The Tint

Streaming along...

There is a whole, fascinating science to river and stream structure, and with so many implications for understanding how these structures and mechanisms affect fish population, occurrence, behavior, and ecology, it's well worth studying for aquarium interpretation!  

Leaf litter beds form in what stream ecologists call "meanders", which are stream structures that form when moving water in a stream erodes the outer banks and widens its "valley", and the inner part of the river has less energy and deposits silt- or in our instance, leaves.

Did you get that part where I mentioned that the lower-energy parts of the water courses tend to accumulate leaves and sediments and stuff?

It's logical, right? And it's also interesting, because, as we know, fishes and their food items tend to aggregate in these areas, and embracing the "theme" of a litter/botanical bed or even wood placement,  in the context of a stream structure in the aquarium is kind of cool!

You could build upon, structure, and replace leaves and botanicals in this "framework"- like, indefinitely...sort of like what happens in the "meanders in streams!"

In Nature, the rain and winds also effect the depth and flow rates of many of the waters in this region, with the associated impacts mentioned above, as well as their influence on stream structures, like submerged logs, sandbars, rocks, etc.

Stuff gets redistributed constantly.

Is there an aquarium "analog" for these processes?

Sure!

We might move a few things around now and again during maintenance, or perhaps current or the fishes themselves act to redistribute and aggregate botanicals and leaves in different spots in our aquairums.

And how we structure the more "permanent" hardscape features in our tanks has a profound influence on how botanical materials can aggregate.

So, rather than covering the whole bottom of your tank with leaves, would it be cool to create some sort of hardscape structure- with driftwood, etc., to retain or keep these items in one place..to create a "framework" for a long-term, organized, specifically-placed litter bed.

The composition of bottom materials and the depth of the channel are always changing in response to the flow in a given stream, affecting the composition and ecology in many ways. I'll probably state this idea more than once in this piece, because it's really important:

Every stream is unique. Although there are standard structural or functional elements common to many streams, each stream is essentially a "custom response" to local ecological, topographical, meteorological, and biological factors.

Permanent streams will often have different volume and material composition (usually finely-packed sands and gravels, with lots of smooth stones) than more intermittent streams, which are the result of inundation caused by rain, etc., or even  so-called "ephemeral" streams, often packed with leaves and lighter sediments, which typically occur only immediately after rain events (which means they usually don't have fish in them unless they are washed into them from more permanent watercourses).

 

The latter two stream types are typically more affected by leaves, botanical debris, branches, and other materials. Like the igarapes ("canoe ways") of Brazil...little channels and rivulets which come and go with the seasonal rains. And then, there's those flooded Igapo forests we obsess over.

In the overall Amazon region (you knew I was sort of headed back that way, right?), it sort of works both ways, with the rivers influencing the surrounding land...and then the land "giving" some of the materials back to the rivers...the extensive lowland areas bordering the river and its tributaries, known as varzeas (“floodplains”), are subject to annual flooding, which helps foster enrichment of the aquatic environment.

Much of them come from trees.

Yeah, trees.

The materials that comprise the tree are known in ecology as "allochthonous material"-  something imported into an ecosystem from outside of it.  (extra points if you can pronounce the word on the first try...) And of course, in the case of trees, this also includes includes leaves, fruits and seed pods that fall or are washed into the water along with the branches and trunks that topple into the stream.  

You know, the stuff we obsess over around here!

Although many streams derive their food base from leaves and organic matter, there is a lot of other material present that contributes to its structure. Think along those lines when scheming your next aquarium. Ask yourself what factors would contribute to the bottom composition of the area you're taking inspiration from.

There seems to be a pervasive mindset within the botanical method aquarium hobby that you need to incorporate a wide variety of botanicals into every aquarium. I would like to go on record right now to state that this is simply untrue. You can use as little or as much diversity of materials as you'd like;

Nature doesn't have a "standard" for this!

It's a "guideline" which I believe vendors have placed into the collective consciousness of the hobby for reasons that are not entirely altruistic. Personally, I will only use a one or two types of botanical materials in a given aquarium. Maybe three, but that's typically it. This mindset was forged by both my aesthetic preferences and my studying of the characteristics of many of the natural habitats which we model our aquariums after.

They simply don't have an unlimited variety of materials present. Rather, the composition of the accumulated  materials in most wild aquatic habitats is limited- often based upon the plants in the immediate vicinity, as well as other factors, like currents (when present) and winds. During storms, materials can be re-distributed from outside of the immediate environment, adding to the diversity of accumulation.

In general, one of the ecological roles of streams are to distribute materials throughout the greater ecosystem. Streams have interesting morphologies. It's interesting to consider the structural components of a stream, to get a better picture of how it forms and functions. What are the key components of streams?

 

Well, there is the top end of a stream, where its flow begins..essentially, its source. The "bottom end" of a stream is known as its "mouth." In between, the stream flows through its main course, also known as a "trunk." Streams gain their water through runoff, the combined input of water from the surface and subsurface.

Streams which flow over stony, open bottoms, free from natural obstacles like tree trunks and such, tend to develop a rich algal turf on their surfaces.

While not something a lot of hobbyists like to see in their tanks (with the exception of Mbuna guys and weirdos like me), algae-covered stones and rocks are entirely natural and appropriate for the bottom of many aquariums! (enter a tank with THAT in the next international aquascaping contest and watch the ensuing judge "freak-out" it causes! )

Grazing fishes, of course, will feed extensively on or among these algal films, and would be logical choices for a stony-bottom-themed aquarium. Like Labeo ("Sharks"), Darter characins, and barbs. When we think about the way natural fish communities are assembled in rivers and streams, it's almost always as a result of adaptations to the physical environment and food resources.

Now, not everyone wants to have algae-covered stones or a mass of decomposing leaves on the bottom of their aquarium.  I totally get THAT! However, I think that considering the role that these materials play in the composition of streams and the lives of the fishes which inhabit them is important, and entirely consistent  with our goal of creating the most natural, effective aquariums for the animals which we keep.

As a hobbyist, you can employ elements of these natural systems in a variety of aquariums, using any number of readily-available materials to do the job. And, let's face it; pretty much no matter how we 'scape a tank- no matter how much- or how little- thought and effort we put into it, our fishes will ultimately adapt to it.

They'll find the places they are comfortable hiding in. The places they like to forage, sleep and spawn. It doesn't matter if your 'scape consists of carefully selected roots, seed pods, rocks, plants, and driftwood, or simply a couple of clay flower pots and a few pieces of egg crate- your fishes will "make it work."

As aquarists, observing, studying, and understanding the specifics of streams is a fascinating and compelling part of the hobby, because it can give us inspiration to replicate the form and more important- the function-  of them in our tanks!

Now, you're also likely aware of the fact that we're crazy about small, shallow bodies of water, right? I mean, almost every fish geek is like "genetically programmed" to find virtually any random body of water irresistible!

Especially little rivulets, pools, creeks, and the aforementioned forest streams. The kinds which have an accumulation of leaves and botanical materials on the bottom. Darker water, submerged branches- all of that stuff...

You know- the kind where you'll find fishes!

Happily, such habitats exist all over the world, leaving us no shortage of inspiring places to attempt to replicate. Like, everywhere you look!

In Africa for example, many of these little streams and pools are home to some of my fave fishes, killifish! This group of fishes is ecologically adapted to life in a variety of unusual habitats, ranging from puddles to small streams to mud holes. However, many varieties occur in those streams in the jungles of Africa.

And many of these little jungle streams are really shallow, cutting gently through accumulations of leaves and forest debris.  Many are seasonal. The great killie documenter/collector, Col. Jorgen Scheel, precisely described the water conditions found in their habitat  as "...rather hot, shallow, usually stagnant & probably soft & acid."

Ah-ah! We know this territory pretty well, right?

I think we do...and understanding this type of habitat has lots of implications for creating very cool biotope-inspired aquariums. 

And why not make 'em for killifish?

So, yeah- we keep talking about "very shallow jungle streams." How shallow? Well, reports I've seen have stated that they're as shallow as 2 inches (5.08cm). That's really shallow. Seriously shallow! And, quite frankly, I'd call that more of a "rivulet" than a stream!

"Virtually still, with a barely perceptible current..." was one description. That kind of makes my case!

What does that mean for those of us who keep small aquariums?

Well, it gives us some inspiration, huh? Ideas for tanks that attempt to replicate and study these compelling shallow environments...

Now, I don't expect you to set up a tank with a water level that's 2 inches deep..And, although it would be pretty cool, for more of us, perhaps a 3.5"-4" (8.89-10.16cm) of depth is something that can work? Yeah. Totally doable. There are some pretty small commercial aquariums that aren't much deeper than 6"-8" (20.32cm). 

We could do this with some of the very interesting South American or Asian habitats, too...Shallow tanks, deep leaf litter, and even some botanicals for good measure.

How about a long, low aquarium, like the ADA "60F", which has dimensions of 24"x12"x7" (60x30x18cm)? You would only fill this tank to a depth of around 5 inches ( 12.7cm) at the most. But you'd use a lot of leaves to cover the bottom...

Yeah, to me, one of the most compelling aquatic scenes in Nature is the sight of a stream meandering into the forest.

There is something that calls to me- beckons me to explore, to take not of its intricate details- and to replicate some of its features in an aquarium- sometimes literally, or sometimes,. just taking components that I find compelling and utilizing them.

An important consideration when contemplating such a replication in our tanks is to consider just how these little forests streams form. Typically, they are either a small tributary of a larger stream, with the path carved out by rain or erosion over time. In other situations, they may simply be the result of an overflowing tributary during the rainy season, and as the waters recede later in the year, they evolve into smaller streams meandering through vegetation.

Those little streams fascinate me.

In Brazil, they are known as igarape, derived from the native Brazilian Tupi language. This descriptor incorporates the words "ygara" (canoe) and "ape"(way, passage, or road) which literally translates into "canoe way"- a small body of water which forms a route navigable by canoes.

A literal path through the forest!

These interesting little tributaries areare shaded by trees at the margins, and often cut for many kilometers through dense rain forest. The bottoms of these tributaries- formerly forest floor- are often covered with seed pods, twigs, leaves, and other botanical materials from the vegetation above and surrounding them. 

Although igapó forests are characterized by sandy acidic soils that have a low nutrient content, the tributaries that feed them are often found over a fine-grained, whitish sand, so as an aquarist, you a a lot of options for substrate!

In this world of decomposing leaves, submerged logs, twigs, and seed pods, there is a surprising diversity of life forms which call this milieu home. And each one of these organisms has managed to eke out an existence and thrive.

A lot of hobbyists not familiar with our aesthetic tastes will ask what the fascination is with throwing palm fronds and seed pods into our tanks, and I tell them that it's a direct inspiration from Nature! Sure, the look is quite different than what has been proffered as "natural" in recent years- but I'd guarantee that, if you donned a snorkel and waded into one of these habitats, you'd understand exactly what we are trying to represent in our aquariums in seconds!

Streams, rivulets...whatever they're called- they beckon us. Compel us. And challenge us to understand and interpret Nature in exciting new ways in our aquariums. 

I think we're starting to see a new emergence of a more "holistic" approach to aquarium keeping...a realization that we've done amazing things so far, keeping fishes and plants in a glass or acrylic box with applied technique and superior husbandry...but that there is room to experiment and push the boundaries even further, by understanding and applying our knowledge of what happens in the real natural environment. 

Think differently. Expand your horizons.

Stay curious. Stay creative. Stay brave. Stay studious...

And Stay Wet.

Scott Fellman

Tannin Aquatics

 

Constantly Changing. Persistently Evolving...

I make it no secret that the botanical method aquarium is unlike almost any other approach to aquarium keeping currently practiced. Not better. Not the "coolest" (well, possibly...)- just different. To parse all of the many reasons why this approach is so different could literally take years...Oh, wait, it HAS..like 8 years, to be exact! 

If you take this approach, you simply, literally- need to clear your mind of any preconceived notions that you have about what an aquarium should look like. The aesthetics are unlike anything that you've seen before in the hobby. 

And, over the many years that I've been playing with botanicals, my approaches and processes have changed and evolved, based on my own experiences, and those of our community. The way I approach botanical method aquariums today is definitely a bit different than I have approached them previously.

And that's pretty cool..It's the by-product of years of playing with this stuff; modifying techniques, philosophies, and approaches based upon actual practice.

My practices are constantly changing...Persistently evolving.

Here are a few examples of the evolution of my practices and approaches over the years. 

As a regular consumer of our content, you likely know of my obsession with varying substrate compositions and what I call "enhancement" of the substrate- you know, adding mixes of various materials to create different aesthetics and function.

Over the years, I've developed a healthy interest in replicating the function and form of substrates found in the wild aquatic habitats of the world. What we had to work with in years past in the hobby was simply based upon what the manufacturers had available. I felt that, although these materials are overall great, there was a lot of room for improvement- and some evolution based upon what types of materials are found in actual wild aquatic habitats.

My evolution was based upon really studying the wild habitats and asking myself how I can replicate their function in my tanks. A big chunk of this understanding came from studying how substrate materials in the wild aggregate and accumulate; where they come from, and what they do for the overall aquatic ecosystem.

I'm fascinated with this stuff partly because substrates and the materials which comprise them are so intimately tied to the overall ecology of the aquatic environments in which they are found. Terrestrial materials, like soils, leaves, and bits of decomposing botanical materials become an important component of the substrate, and add to the biological function and diversity.

Now, there is a whole science around aquatic substrates and their morphology, formation, and accumulation- I don't pretend to know an iota about it other than skimming Marine biology/hydrology books and papers from time to time. However, merely exploring the information available on the tropical aquatic habitats we love so much- even just looking long and hard at some good underwater pics of them- can give us some good ideas!

How do these materials find their way into aquatic ecosystems?

In some areas- particularly streams which run through rain forests and such, the substrates are often simply a soil of some sort. A finer, darker-colored sediment or soil is not uncommon. These materials can profoundly influence water chemistry,  based on the ionic, mineral, and physical concentrations of materials that are dissolved into the water. And it varies based on water velocities and such. 

Meandering lowland rivers maintain their sediment loads by continually re-suspending and depositing materials within their channels- a key point when we consider how these materials arrive-and stay- in the aquatic ecosystems.

Forest floors...Fascinating ecosystems in their own right, yet even more compelling when they're  flooded. 

And what accumulates on dry forest floors?

Branches, stems, and other materials from trees and shrubs. When the waters return, these formerly terrestrial materials become an integral part of the (now) aquatic environment. This is a really, really important thing to think of when we aquascape or contemplate who we will use botanical materials like the aforementioned stems and branches. They impact both function and aesthetics of an aquarium...Yes, what we call "functional aesthetics" rears its head again!

There is no real rhyme or reason as to why stuff orients itself the way it does. I mean, branches fall off the trees, a process initiated by either rain or wind, and just land "wherever." Which means that we as hobbyists would be perfectly okay just sort of tossing materials in and walking away! Now, I know this is actually aquascaping heresy- Not one serious 'scaper would ever do that...right?

I'm not so sure why they wouldn't.  Look at Nature...

I mean, what's wrong with sort of randomly scattering stems, twigs, and branches in your aquascape? It's a near-perfect replication of what happens in Nature. Now, I realize that a glass or acrylic box of water is NOT nature, and there are things like "scale" and "ratio" and all of that "gobbldeygook" that hardcore 'scaping snobs will hit you over the head with...

But Nature doesn't give a shit about some competition aquascaper's "rules"- and Nature is pretty damn inspiring, right? There is a beauty in the brutal reality of randomness. I mean, sure, the position of stones in an "Iwagumi" is beautiful...but it's hardly what I'd describe as "natural."

 We talk a lot about "microhabitats" in Nature; little areas of tropical habitats where unique physical, environmental and biological characteristics converge based on a set of factors found in the locale. Factors which determine not only how they look, but how they function, as well.

The complexity and additional "microhabitats" they create are compelling and interesting. And they are very useful for shelltering baby fishes, breeding Apistogramma, Poecilocharax, catfishes, Dicosssus, an other small, shy fishes which are common in these habitats. 

Small root bundles and twigs are not traditionally items you can find at the local fish store or online. I mean, youcan, but there hasn't been a huge amount of demand for them in the aquascaping world lately...although my 'scape scene contacts tell me that twigs are becoming more and more popular with serious aquascapers for "detailed work"...so this bodes well for those of us with less artistic, more functional intentions!

Except we don't glue shit together. 

When I see aquascapers glue wood together, it makes me want to vomit. I know, I'm an asshole for feeling that way, but it's incredibly lame IMHO. Just fit the shit together with leverage and gravity, like your grandparents did, or keep looking for that perfect piece. Seriously! You don't need to glue to make wood look "cool."  

You're not a reefer gluing coral frags to rock. There is no "need" to do this. 

Relax and just put it together as best as Nature will allow.

Okay, micro rant over!

Let's get back to discussing natural materials and how we've come to include them in our tanks just a bit more...

Like, roots.

In flooded forests, roots are generally found in the very top layers of the soil, where the most minerals are. In fact, in some areas, studies indicated that as much as 99% of the root mass in these habitats was in the top 20cm of substrate! Low nutrient availability in the Amazonian forests is partially the reason for this. And since much of that root mass becomes submerged during seasonal inundation, it becomes obvious that this is a unique habitat.

So, ecological reasons aside, what are some things we as hobbyists can take away from this?  

We can embrace the fact that most of these finer materials will function in our aquairums as they do in Nature, sequestering sediments, retaining substrate, and recruiting epiphytic materials which fishes will forage, hide, and spawn among.

Functional aesthetics.

And let's talk about preparation a bit.

I'm at a phase in my aquarium "career" with regards to botanicals in which I feel it is less and less necessary to worry about extensively preparing my botanical materials for use in my tanks. In essence, my main preparation "technique" is to rinse the items briefly in freshwater, followed by a boil until they are saturated and stay submerged.

It's less and less about "cleaning them" and more and more about getting them to  stay down in my aquairums. And to be perfectly honest, if the materials would actually sink immediately and stay down, I think my "preparation" would simply consist of a good rinse!

What's the reason for this "evolution" of my preparation technique? Well, part of it is because I've started to realize that virtually every botanical item which I use in my work is essentially "clean"- that is, not polluted or otherwise contaminated. Generally, most of the items I use may simply have some "dirt" on their surfaces. I typically will not use botanical items which have bird droppings, insect eggs, or other obvious contaminants present. 

The reality is that, in over 20 years of playing with botanicals, I simply cannot attribute a single fish death to the use of improperly prepared botanical materials!

It's really more about the sourcing, to me. 

Naturally collected materials, air or sun-dried over time are just not an issue. However, when you obtain materials from unvetted sources, you cannot be sure what her original intended use was. For years, the "hack" I've seen was hobbyists purchasing dried botanical materials from craft stores...And these are the people I've seen the most issues with. 

The problem is that materials intended to be used in craft projects are typically chemically preserved or treated with varnishes or other materials...and these are simply deadly to aquatic life.

Feel free to experiment with all sorts of carefully collected natural materials, but I would simply avoid purchasing them from sources which you cannot thoroughly vet. The price of such "hacks" may be the deaths of your fishes.

Another reason I'm less "anal" about preparation of my botanicals and wood and such is that these materials contain a lot of organic materials which are likely "catalysts" for ecological processes. I know, that's vague and oddly unscientific, but it makes sense, when you think about it.

"Organics" are simply incorporated into the aqueous environment, and help foster the growth of a variety of organisms, from fungi to bacterial biofilms and more.  IMHO, they are helpful to create an underwater ecology in your aquirium.  It's no longer a concern of mine that botanicals being added to my aquairums need to be essentially "sterile."

Ecology is the primary motivation for me when it comes to adding botanicals to my tanks- specifically, helping to foster an underwater ecology which will provide the inhabitants with supplemental food and nutrient processing. So, trying to keep things impeccably clean when setting up an ecology first, botanical method aquarium is downright counterproductive, IMHO.

And I have a hunch that a lot of our fear of introducing extraneous "stuff" into our tanks via botanicals was as a result of my excessive paranoia back in 2015, in our earliest days- when I was very concerned about some hobbyist simply dumping a bunch  of our fresh botanicals into his/her tank and ending up with...well, what?

A tank with a little bid of turbidity? Darkly tinted water? Some fungal and biofilm-encrusted seed pods and leaves? Detritus from their tissues?

All things that we've come to not only accept, but to expect and to even celebrate as a normal part of our practice. I mean, man, there is literally an explosion of hashtags used on instagram weekly celebrating shit that I used to have to beat you over the head about to convince you that these things were normal: "Detritus Thursday", "Fungal Friday", etc. 

And, isn't this what you see in wild aquatic habitats?

None of these things are "bad." We're beyond these concerns that were partially rooted in fear, and the other part in our desire to fit in with the mainstream hobby crowd's aesthetic preferences. We've finally accepted that our "normal" is very different from almost every other hobby specialty's view of "normal." 

My development, use, and marketing of our NatureBase line of sedimented substrates reflected another big step in my growing confidence about what is "normal: in our world. These substrates are filled with materials which will make your water turbid for a while...and we absolutely DON'T recommend any sort of preparation before using them. 

Your tank WILL get cloudy for a few days...Absolutely part of the process. I remember a lot of sleepless nights, discussions with Johnny Citotti and Jake Adams before launching the product, and just convincing myself that it was okay to convince fellow hobbyists to...relax bit about this stuff and embrace it, in exchange for the manifold benefits of utilizing more truly natural substrate materials.

The entire botanical method aquarium movement has been, and likely will continue to be- an exercise in stepping out of our hobby "comfort zones" on a regular basis. Trying out ideas which have long been contrary to mainstream  aquairum hobby practice and philosophy. Ideas and practices which question and challenge the "status quo", and seem to go against a century of aquarium work, in favor of embracing the way Nature has done things for eons.

It's a big "ask", but you keep accepting it...and we've all grown together as a result. 

Another seismic shift (in my head, anyways...) is my acceptance that... leaves are leaves. Yeah, seriously. Wether they come from the rainforest of Borneo or the mountains of West Virginia, leaves are essentially similar to each other. Sure, soem look different, or perhaps might have different concentrations of compounds within their tissues...yet they're all fundamentally the same. They perform the same function for the tree, and "behave" similarly when submerged in water. 

A Catappa leaf from Malaysia, Jackfruit leaf from India, or a Live Oak leaf from Southern California are more alike than they are dissimilar. Other than having slightly different concentrations of tannins (and even that is possibly minimal), a leaf is a leaf. To convene ourselves otherwise is kind of funny, actually.

I did for a long time. I was 100% convinced that the leaves I was painstakingly sourcing from remote corners of the globe were somehow better than our Native Magnolia or Live Oak or whatever. The reality is that, other than some exotic sounding names, a morphology that might be different, or a good story about where they  come from, the "advantages" of most "exotic" leaves over "domestically sourced" leaves  ( or leaves from wherever you come from) are really minimal at best.

Trust me- no Catappa leaves find their way into tributaries of the Orinoco river. It's Ficus, Havea leaves, various palms, etc. 

But not Catappa, Guava, or Jackfruit. 

And if they did, they likely impact the water chemistry or ecology no differently.

Leaves are leaves. In fact, ecologically, they all essentially do the same thing, just on a different "timetable." Trees in tropical deciduous forests lose their leaves in the dry season and regrow them in the rainy season, whereas, temperate deciduous forests, trees lose their leaves in the fall and regrow them in the spring.

In the moist forests close to the equator, the climate is warm and there is plenty of rainfall all year round. In this environment there is no reason for the trees to drop their leaves at any particular time of year, so the forest stays green year round. 

Trees from temperate climate zones lose leaves regularly during certain times of the year and then regrow them., and must take a fairly precise cue from their environment. In the mid and high latitudes, if trees put the leaves out too early in the year, these may be damaged by frost and valuable nutrients lost, because the tree cannot easily reclaim nutrients from a frost-bitten leaf.

Yeah, leaves...They perform similar functions for their trees, regardless of where they come from.

The morphological differences are often subtle, and sometimes inconsistent:

It has long been recognized by science that tropical forests are dominated by evergreen trees that have leaves with "complete" margins, whereas trees of temperate forests tend to have deciduous leaves with toothed or lobed margins.

Maybe leaves from different habitats and environments  look a bit different, and fall at different times...but that's really about it... 

I'm sure that this is not an "absolute" sure- there ARE trees which have leaves with higher concentrations of tannins, etc than others...However, by and large, there are not all that many compelling arguments to favor "exotic" leaves from faraway places over the ones you can source locally! 

Sure, soem botanist somewhere could school my on over-generalizing this, but in the aquairum world, I'm not certain one could successfully prove that you MUST use "Pango Pango leaves" from Cameroon to be successful with botanical method aquariums. Now, could one argue that there are some subtle chemical ben efiots to fishes from these regions by using "local" botanicals in their tanks? Maybe. But by and large, I just don't think so anymore.

So,as a hobbyist and vendor, I'm not completely engrossed by chasing every exotic sounding leaf out there anymore. 

I may offer limited quantities of the "big three" in the future, but I feel less and less compelled to do so. Trying to be the aquarium world's "catalogue" of tropical leaves for aquariums long ago lost its luster, among the realities of supply chain issues, tariffs, and unreliable producers. Let other vendors chase the dollars. I'm going to chase my ideas...and use whatever materials I see fit for purpose- regardless of their origin.

Constantly changing. Persistently Evolving.

 

We're in an amazing time right now. For the first time in years, I personally feel that the idea of botanical method aquariums has moved out of it's obscure, "fringe-culture-like" parking spot in the fish world, and into the light of the mainstream. 

And it's all because of YOU! Sure, many of you were playing with "blackwater" tanks before, but if your experience was anything like mine, you were sort of viewed as a mildly eccentric hobbyist playing with a little "side thing"- a passing fancy that you'd eventually "get over.." 

Well, I think that is changing a lot now. We're seeing a community of what was once widely scattered hobbyists starting to come together and share ideas, technique, pictures, inspiration with other equally as obsessed hobbyists. This is an amazing thing to me, and to be able to witness it firsthand is incredible! It's been a renaissance of sorts for this once-neglected aspect of the hobby.

Another think that I think is interesting is that we, as a community, are viewing our aquariums as "habitats" more than ever before. We  seem to have broken through the mindset of creating aquariums only based on an aesthetic WE like, and fitting the fishes into it, as opposed to creating aquariums with specialized habitats for specific fishes. 

And we're not afraid to make little detours- small changes. And, not all of them need be intentional. Things happening in unexpected ways are what can propel the hobby forward.

Everything doesn't have to follow a plan.

A detour can be amazing.

However, if your looking for a specific result and go too far in a different direction, it's often a recipe for frustration for those of us not prepared of it. Sure, many of us can simply "go with the flow" and accept the changes we made as part of the process, but the aquarist with a very pure vision and course will work through such self-created deviations until he or she gets to the destination.

Many find this completely frustrating.

Others find this a compelling part of the creative process.

Pretty much every major breakthrough I've encountered in my hobby "practice" has been the result of me "breaking pattern" and trying something fairly radically new...You know, a big remake of an aquarium....Trying a new manipulation of the environment, etc.

And of course, the thing which maintains the "breakthrough?"

Well...

I've always had this thing about repetition and doing the same stuff over and over agin in my aquarium practice. It's one of the real "truisms", to me, about fish keeping: Once you've gotten in a groove, in terms of husbandry routines, it's great to just do the same thing over and over again. 

Consistency.

Yes, I beat the shit out of that idea fairly regularly, right?

Now, notice that I'm not talking about doing the same thing over and over when it comes to ideas...Nope. I'm of the opinion that you should do all sorts of crazy things when it comes to concepts and experiments.

 One thing that was sort of "experimental" for many years in my world was the idea of NOT removing decomposing botanical materials from my tanks. You know, flat-out siphoning stuff out, lest it do "something" to the water quality in my aquariums.

It was a big deal about 20 years ago...People thought I was crazy for talking about leaving leaves and botnaicals in the tank until they fully decomposed. I was told that if I didn't remove this stuff, all sorts of horrifying outcomes would ensue. Yet, in the back of my mind, I thought to myself, "If the whole idea of botanical method aquariums is to facilitate an ecosystem within the tank, wouldn't removing a significant source of the ecology (ie; decomposing leaves and botanical detritus) be MORE negative than leaving iot in the tank to be "worked" by the resident life forms at various levels?

So I left the stuff in...

Never had any "bad" results...

It really wasn't that surprising, in actuality.

I figured that this would actually be beneficial to the aquairum...My theory was steeped in the mindset that you've created a little ecosystem, and if you start removing a significant source of someone's food (or for that matter, their home!), there is bound to be a net loss of biota...and this could lead to a disruption of the very biological processes that we aim to foster.

Okay, it was a theory...But I think I am on to something, maybe? So, like here is my "theory" in more detail:

Simply look at the botanical-method aquarium (like any aquarium, of course) as a little "microcosm", with processes and life forms dependent upon each other for food, shelter, and other aspects of their existence. And, I really believe that the environment of this type of aquarium, because it relies on botanical materials (leaves, seed pods, etc.), is more signficantly influenced by the amount and composition of said material to "operate" successfully over time.

Just like in natural aquatic ecosystems...

Detritus...the nemesis of the hobby...not all that bad, really..

It's all about not simply accepting the generally held hobby "truisms" as "gospel" in EVERY situation. Experimenting and considering stuff in context is important. 

Change and variation is inevitable and important in the hobby. Being open minded about things is vital. 

The processes of evolution, change and disruption which occur in natural aquatic habitats- and in our aquariums- are important on many levels. They encourage ecological diversity, create new niches, and revitalize the biome. Changes can be viewed as frightening, damaging events...Or, we can consider them necessary processes which contribute to the very survival of aquatic ecosystems.

Think about that the next time you hesitate to experiment with that new idea, or play a hunch that you might have. Remember that there is always a bit of discomfort, trepidation, and risk when you make changes or conduct bold experiments. 

Goes with the territory, really.

However, once you get out of that comfort zone, you're really living...and the fear will give way to exhilaration and maybe even triumph! Because in the aquarium hobby, the bleeding edge is when you're constantly changing, and patiently evolving.

Stay Brave. Stay persistent. Stay curious. Stay thoughtful. Stay creative...

And Stay Wet.

 

Scott Fellman

Tannin Aquatics 

 

 

Race to the bottom...

.

Substrates, IMHO, are one of the most often-overlooked components of the aquarium. We tend to just add a bag of  "_____________" to our tanks and move on to the "more exciting" stuff like rocks and "designer" wood. It's true! Other than planted aquarium enthusiasts, the vast majority of hobbyists seem to have little more than a passing interest in creating and managing a specialized substrate or associated ecology.

And, when we observe natural aquatic ecosystems, I think we as a whole tend to pay scant little attention to the composition of the materials which form the substrate; how they aggregate, and what occurs when they do. 

I'm obsessed with the idea of "functionally aesthetic" substrates in our botanical-style aquariums. 

It's because I imagine the substrate as this magical place which fuels all sorts of processes within our aquariums, and that Nature tends to it in the most effective and judicious manner. 

Yeah, I'm a bit of a "substrate romantic", I suppose.😆

I think a lot of this comes from my long experience with reef aquariums, and the so-called "deep sand beds" that were quite popular in the early 2000's.

A deep sand bed is (just like it sounds) a layer of fine sand on the bottom of the aquarium, intended to grow bacteria in the deepest layers, which convert nitrate or nitrite to nitrogen gas. This process is generically called "denitrification", and it's one of the benefits of having an undisturbed layer of substrate on the bottom of the aquarium.

Fine sand and sediment is a perfect "media" upon which to culture these bacteria, with its abundant surface area. Now, the deep sand bed also serves as a location within the aquarium to process and export dissolved nutrients, sequester detritus (our old friend), and convert fish poop and uneaten food into a "format" that is usable by many different life forms.

In short, a healthy, undisturbed  sandbed is a nutrient processing center, a supplemental food production locale, and a microhabitat for aquatic organisms. 

You probably already know most of this stuff, especially if you've kept a reef tank before. And of course, there are reefers who absolutely vilify sandbeds, because they feel that they "compete" with corals, and ultimately can "leach" out the unwanted organics that they sequester, back into the aquarium. I personally disagree with that whole thing, but that's another battle for another time and place! 

Okay, saltwater diversion aside, the concept of a deep substrate layer in a botanical-style aquarium continues to fascinate me. I think that the benefits for our systems are analogous to those occurring in reef tanks- and of course, in Nature. In my opinion, an undisturbed deep substrate layer in the botanical-style aquarium, consisting of all sorts of materials, from sand/sediments to leaves to twigs and broken-up pieces of botanicals,can foster all sorts of support functions.

I've always been a fan of in my aquarium keeping work of allowing Nature to take its course in some things, as you know. And this is a philosophy which plays right into my love of dynamic aquarium substrates. If left to their own devices, they function in an efficient, almost predictable manner.

Nature has this "thing" about finding a way to work in all sorts of situations.

And, I have this "thing" about not wanting to mess with stuff once it's up and running smoothly... Like, I will engage in regular maintenance (ie; water exchanges, etc.), but I avoid any heavy "tweaks" as a matter of practice. In particular, I tend not to disturb the substrate in my aquariums. A lot of stuff is going on down there...

Amazing stuff.

I realize, when contemplating really deep aggregations of substrate materials in the aquarium, that we're dealing with closed systems, and the dynamics which affect them are way different than those in Nature, for the most part.

And I realize that experimenting with these unusual approaches to substrates requires not only a sense of adventure, a direction, and some discipline- but a willingness to accept and deal with an entirely different aesthetic than what we know and love. And this also includes pushing into areas and ideas which might make us uncomfortable, not just for the way they look, but for what we are told might be possible risks.

One of the things that many hobbyists ponder when we contemplate creating deep, botanical-heavy substrates, consisting of leaves, sand, and other botanical materials is the buildup of hydrogen sulfide, CO2, and other undesirable compounds within the substrate.

Well, it does make sense that if you have a large amount of decomposing material in an aquarium, that some of these compounds are going to accumulate in heavily-"active" substrates. Now, the big "bogeyman" that we all seem to zero in on in our "sum of all fears" scenarios is hydrogen sulfide, which results from bacterial breakdown of organic matter in the total absence of oxygen.

Let's think about this for just a second.

In a botanical bed with materials placed on the substrate, or loosely mixed into the top layers, will it all "pack down" enough to the point where there is a complete lack of oxygen and we develop a significant amount of this reviled compound in our tanks? I think that we're more likely to see some oxygen in this layer of materials, and I can't help but speculate- and yeah, it IS just speculation- that actual de-nitirifcation (nitrate reduction), which lowers nitrates while producing free nitrogen, might actually be able to occur in a "deep botanical" bed.

There is that curious, nagging "thing" I have in my head about the ability of botanical-influenced substrates to foster denitrification. With the diverse assemblage of microorganisms and a continuous food source of decomposing botanicals "in house", I can't help but think that such "living substrates" create a surprisingly diverse and utilitarian biological support system for our aquariums.

And it's certainly possible to have denitrification without dangerous hydrogen sulfide levels. As long as even very small amounts of oxygen and nitrates can penetrate into the substrate, this will not become an issue for most systems. I have yet to see a botanical-style aquarium where the material has become so "compacted" as to appear to have no circulation whatsoever within the botanical layer.

Now, sure, I'm not a scientist, and I base this on close visual inspection of numerous aquariums, and the basic chemical tests I've run on my systems under a variety of circumstances. As one who has made it a point to keep my botanical-method aquariums in operation for very extended time frames, I think this is significant. The "bad" side effects we're talking about should manifest over these longer time frames...and they just haven't.

And then there's the question of nitrate. 

Although not the terror that ammonia and nitrite are known to be, nitrate is much less so. However, as nitrate accumulates, fish will eventually suffer some health issues. Ideally, we strive to keep our nitrate levels no higher than 5-10ppm in our aquariums.  As a reef aquarist, I've always been of the "...keep it as close to zero as possible." mindset (that's evolved in recent years, btw), but that is not always the most realistic or achievable target in a heavily-botanical-laden aquarium. You have a bit more "wiggle room", IMHO. Now, when you start creeping towards 50ppm, you're getting closer towards a number that should alert you. It's not a big "stretch" from 50ppm to 75ppm and higher...

And then you get towards the range where health issues could manifest themselves in your fishes. Now, many fishes will not show any symptoms of nitrate poisoning until the nitrate level reaches 100 ppm or more. However,  studies have shown that long-term exposure to concentrations of nitrate stresses fishes, making them more susceptible to disease, affecting their growth rates, and inhibiting spawning in many species. 

At those really high nitrate levels, fishes will become noticeably lethargic, and may have other health issues that are obvious upon visual inspection, such as open sores or reddish patches on their skin. And then, you'd have those "mysterious deaths" and the sudden death (essentially from shock) of newly-added fishes to the aquarium, because they're not acclimated to the higher nitrate concentrations.

Okay, that's scary stuff. However, high nitrate concentrations are not only manageable- they're something that's completely avoidable in our aquairums.

Quite honestly, even in the most heavily-botanical-laden systems I've played with, I have personally never seen a higher nitrate reading than around 5ppm. I attribute this to  common sense stuff: Good quality source water (RO/DI), careful stocking, feeding, good circulation, not disturbing the substrate, and consistent basic aquarium husbandry practices (water changes, filter maintenance, etc.).

Now, that's just me. I'm no scientist, certainly not a chemist, but I have a basic understanding of maintaining a healthy nitrogen cycle in the aquarium. And I am habitual-perhaps even obsessive- about consistent maintenance. Water exchanges are not a "when I get around to it" thing in my aquarium management "playbook"- they're "baked in" to my practice.

And I think that a healthy, ecologically varied substrate is one of the keys to a successful botanical method aquarium.

I'm really into creating substrates that are a reasonable representation of the bottom of streams, tributaries, and igapo, as found in the Amazon basin. Each one of these has some unique characteristics, and each one presents an interesting creative challenge for the intrepid hobbyist. Until quite recently, the most common materials we had to work with when attempting to replicate these substrates were sand, natural and colored gravels, and clay-comprised planted aquarium substrates.

I reiterate a "manifesto" of sorts that I played out in  "The Tint" back in 2015: 

"If I have something to say about the matter, you'll soon be incorporating a wide variety of other materials into your biotope aquarium substrate!"

Damn, did I just quote myself?

I did!

If you've seen pictures and videos taken underwater in tropical streams (again, I'm pulling heavily from the Amazonian region), you'll note that there is a lot of loose, soil-like material over a harder mud/sand substrate. Obviously, using an entirely soil-based substrate in an aquarium, although technically possible and definitely cool- could result in a yucky mess whenever you disturb the material during routine maintenance and other tasks. You can, however, mix in some of these  materials with the more commonly found sand.

So, exactly what "materials" am I referring to here?

Well, let's look at Nature for a second.

Natural streams, lakes, and rivers typically have substrates comprised of materials of multiple "grades", including fine, medium, and coarse materials, such as pebbles, gravels, silty clays and sands. In the aquarium, we seem to have embraced the idea of a homogenous particle size for our substrates for many years. Now, don't get me wrong- it's aesthetically just fine, and works great. However, it's not always the most interesting to look at, nor is it necessarily the most biologically diverse are of the aquarium.

A lot of natural stream bottoms are complimented with aggregations of other materials like leaf litter, branches, roots, and other decomposing plant matter, creating a dynamic, loose-appearing substrate, with lots of potential for biological benefits. Of course, we need to understand the implications of creating such "dynamic" substrates in our closed aquariums.

When we started Tannin, my fascination with the varied substrate materials of tropical ecosystems got me thinking about ways to more accurately replicate those found in flooded forests, streams, and diverse habitats like peat swamps, estuaries, creeks, even puddles- and others which tend to be influenced as much by the surrounding flora (mainly forests and jungles) as it is by geology.

And of course, my obsession with botanical materials to influence and accent the aquarium habitat caused me to look at the use of certain materials for what I generically call "substrate enrichment" - adding materials reminiscent of those found in the wild to augment the more "traditional" sands and other substrates used in aquariums to foster biodiversity and nutrient processing functions.

Again, look to Nature...

If you've seen pictures and videos taken underwater in tropical streams (again, I'm pulling heavily from the Amazonian region), you'll note that there is a lot of loose, soil-like material over a harder mud/sand substrate. Obviously, using an entirely mud-based substrate in an aquarium, although technically possible- will result in a yucky mess whenever you disturb the material during routine maintenance and other tasks. You can, however, mix in some other materials with the more commonly found sand.

That was the whole thinking behind "Substrato Fino" and "Fundo Tropical", two of our most popular substrate "enrichment" materials. They are perfect for helping to more realistically replicate both the look and function of the substrates found in some of these natural habitats. They provide surface area for fungal and microbial growth, and interstitial spaces for smalll crustaceans and other organisms to forage upon.

Substrates aren't just "the bottom of the tank..."

Rather, they are diverse harbors of life, ranging from fungal and biofilm mats, to algae, to epiphytic plants. Decomposing leaves, seed pods, and tree branches compose the substrate for a complex web of life which helps the fishes were so fascinated by flourish. And, if you look at them objectively and carefully, they are beautiful.

I encourage you to study the natural environment, particularly niche habitats or areas of the streams, rivers, and lakes- and draw inspiration from the functionality of these zones. The aesthetic component will come together virtually by itself. And accepting the varied, diverse, not-quite-so-pritinh look of the "real thing" will give you a greater appreciation for the wonders of nature, and unlock new creative possibilities.

In regards to the substrate materials themselves, I'm fascinated by the different types of soils or substrate materials which occur in blackwater systems and their clearwater counterparts, and how they influence the aquatic environment.

For example, as we've discussed numerous times over the years, "blackwater" is not cased by leaves and such- it's created via geological processes.

In general, blackwaters originate from sandy soils. High concentrations of humic acids in the water are thought to occur in drainages with what scientists call "podzol" sandy soils. "Podzol" is a soil classification which describes  an infertile acidic soil having an "ashlike" subsurface layer from which minerals have been leached.

That last part is interesting, and helps explain in part the absence of minerals in blackwater. And more than one hobbyist I know has played with the concept of "dirted" planted tanks, using terrestrial soils...hmmm.

Also interesting to note is that fact that soluble humic acids are adsorbed by clay minerals in what are known as"oxisol" soils, resulting in clear waters."Oxisol" soils are often classified as "laterite" soils, which some who grow plants are familiar with, known for their richness in iron and aluminum oxides. I'm no chemist, or even a planted tank geek..but aren't those important elements for aquatic plants? 

Yeah.

Interesting.

Let's state it one more time:

We have the terrestrial environment influencing the aquatic environment, and fishes that live in the aquatic environment influencing the terrestrial environment! T

his is really complicated stuff- and interesting! And the idea that terrestrial environments and materials influence aquatic ones- and vice-versa- is compelling and could be an interesting area to contemplate for us hobbyists! 

 

When ecologists study the substrate composition of aquatic habitats like those in The Amazon, they tend to break them down into several categories, broad though they may be: Rock, sand, coarse leaf litter, fine leaf litter, and branches, trunks and roots.

Studies indicate that terrestrial inputs from rainforest streams provide numerous benefits for fishes, providing a wide range of substrate materials that supported a wider range of fishes than can be found in non-forested streams. One study concluded that,  "Inputs from forests such as woody debris and leaf litter were found to support a diversity of habitat niches that can provide nursing grounds and refuges against predators (Juen et al. 2016). Substrate size was also larger in forest stream habitats, adding to the complexity and variety of microhabitats that can accommodate a greater and more diverse range of fish species (Zeni et al. 2019)."

But wait- there's more! Rainforests create uniquely diverse aquatic habitats.

"Forests can further diversify and stabilize the types of food available for fish by supplying both allochthonous inputs from leaf litter and increased availability of terrestrial insects that fall directly into the water (Zeni and Casatti). Forest habitats can support a diverse range of trophic guilds including terrestrial insectivores and herbivores (Zeni and Casatti).

Riparian forests deliver leaf litter in streams attracting insects, algae, and biofilm, each of which may be vital for particular fish species (Giam et al., Juen et al. ). In contrast, nonforested streams may lack the allochthonous food inputs that support terrestrial feeding fish species..."

Leaf litter- yet again. 

And then there are soils...terrestrial soils- which, to me, are to me the most interesting possible substrates in wild aquatic habitats.

So, the idea of a rich soil substrate that not only accommodates the needs of the plants, but provides a "media" in which beneficial bacteria can grow and multiply is a huge "plus" for our closed aquatic ecosystems. And the concepts of embracing Nature and her processes work really well with the stuff we are playing with.

 

As you've seen over the past few years, I've been focusing a lot on my long-running "Urban Igapo" idea and experiments, sharing with you my adventures with rich soils, decomposing leaf litter, tinted water, immersion-tolerant terrestrial plants, and silty, muddy, rich substrates. This is, I think, an analogous or derivative  concept to the "Walstad Method", as it embraces a more holistic approach to fostering an ecosystem; a "functionally aesthetic" aquarium, rather than a pure aesthetic one.

The importance of incorporating rich soils and silted substrates is, I think, an entirely new (and potentially dynamic) direction for blackwater/botanical-style tanks, because it not only embraces the substrate not just as a place to throw seed pods, wood, rocks, and plants- but as the literal foundation of a stable, diverse ecosystem, which facilitates the growth of beneficial organisms which become an important and integral part of the aquarium.

And that has inspired me to spend a lot of time over the past couple of years developing more "biotope-specific" substrates to compliment the type of aquariums we play with.

When we couple this use of non-conventional (for now, anyways...) substrate materials with the idea of "seeding" our aquariums with beneficial organisms (like small crustaceans, worms, etc.) to serve not only as nutrient processing "assistants", but to create a supplementary food source for our fishes, it becomes a very cool field of work.

As creatures like copepods and worms "work" the substrate and aerate and mix it, they serve to stabilize the aquarium and support the overall environment.

Nutrient cycling.

That's a huge takeaway here. I'm sure that's perhaps the biggest point of it all. By allying with the benthic life forms which inhabit it, the substrate can foster decomposition and "processing"of a wide range of materials- to provide nutrition for plants- or in our case- for the microbiome of the overall system. 

There is so much work to do in this area...it's really just beginning in our little niche. And, how funny is it that what seems to be an approach that peaked and fell into a bit of disfavor or perhaps (unintended) "reclassification"- is actually being "resurrected" in some areas of the planted aquarium world ( it never "died" in others...).

And a variation/application of it is gradually starting to work it's way into the natural, botanical-method aquarium approach that we favor.

Substrates are not just "the bottom." 

They are diverse harbors of life, ranging from fungal and biofilm mats, to algae, to epiphytic plants. Decomposing leaves, seed pods, and tree branches compose the substrate for a complex web of life which helps the fishes we're so fascinated by to flourish.

And, if you look at them objectively and carefully, they are beautiful.

Stay curious. Stay ob servant. Stay thoughtful. Stay bold...

And Stay Wet.

 

Scott Fellman

Tannin Aquaitcs 

Perpetual darkness...

Okay, that was an admittedly "dark"-sounding title, but it's perfectly appropriate for today's topic...How to get- and keep- your water as tinted as possible. Or, at least, what materials would do the best job in terms of "color production."

We as a group are kind of obsessed with this.

And yeah, it's a good question!

Now, first off- let's all remember that the color of the water has absolutely NO relationship to its pH or carbonate hardness. It just doesn't. You can have water that looks super dark brown, yet has a pH of 8.5 or whatever. And conversely, it's just as possible to have crystal clear blue-white water that's soft, and has a pH of 4.5. We have to get beyond the social media-style "blackwater" definition, which seems to be, "If the water is tinted, it's a blackwater aquarium!"

Now, look, if you just want the nice color but could care less about the pH and hardness, that's fine. For the benefit of the hobby as a whole, please don't perpetuate the confusing narrative about blackwater aquariums by telling others that you have "blackwater." You have a "tinted" aquairum. 

And that's just fine.

So, yeah-I'm not going to launch into a long drawn out description today about how ecologists define "blackwater" and what specific chemical characteristics make it up- we've covered it enough over the years...you can deep dive here or elsewhere to get that. 

Okay, micro-rant over. Let's get back to the topic.

Remember, this piece is not about how to make blackwater...It's a little more superficial than that...it's about creating an aquarium with color and maintaining it. 

First off, one of the "keys" to getting your color that lovely brown is to select the right types and quantities of botanical materials to assist. Now, I'll be the very first to raise my hand and call BS on anyone who claims to have a perfect "recipe" for how many Catappa leaves per liter or whatever you must use to achieve a specific color. Sure, you could come up with some generic recommendations, but they're not always applicable to every tank or situation.

Yes...there are simply so many variables in the equation- many which we probably haven't even considered yet-that it would be simply guessing. Just like Nature, to some extent...

What I can do is recommend some materials which we have found over the years to generally impart the most reliable and significant color to water. In no particular order, I'll give you my thought on a few of my personal faves. There are a lot more, but these are some that consistently show up on my "fave" list. 

Wood

Yep, you heard me. One of the very best sources of tint-producing tannins in our aquariums is wood. I've told you many times, wood imparts tannins, lignin, and all sorts of other "stuff" from the exterior surfaces and all of those nooks and crannies that we love so much into the water. 

Ahh...the tannins.

Now, I don't know about you, but I'm always amused (it's not that hard, actually) by the frantic posts on aquarium forums from hobbyists that their water is turning brown after adding a piece of wood. I mean- what's the big deal?

Oh, yeah, not everyone likes it...I forgot that. 😂

The reality, though, as you probably have surmised, is that wood will continue to leach tannins to a certain extent pretty much for as long as it's submerged. As a "tinter", I see this as a great advantage in helping establish and maintain the blackwater look, and to impart humic substances that are known to have health benefits for fishes.

Some wood types, like Mangrove ( a wood we don't have at the moment), tend to release more tannins than others over long periods of time. Other types, like "Spider Wood", will release their tannins relatively quickly, in a big burst. Some, such as Manzanita wood, seem to be really "dirty", and release a lot of materials over long periods of time. All will recruit fungal growths and bacterial biofilms.

And  the biocover on the wood is a unique functional aesthetic, too, as we rant on and on about here!

Bark

I'm a huge fan of tree bark to impart not only color, but beneficial tannins into the water. Because of its composition and structure, bark tends to last a very long time when submerged, and tends to impart a lot of color to the water over the long term.

And to be quite honest, almost all of the bark products we've played with over the years seem to work equally as well. The real difference in bark is the "form factor" (appearance) and the color that they impart to the water over time. Some, such as Red Mangrove bark or Cutch bark, will impart a much deeper, reddish-brown tint to the water than say, an equal quantity of catappa bark. And our soon-to-be-released Ichnocarpus bark really packs in this reddish brown color! You're gonna love this stuff! 

Ounce for ounce, gram for gram, I've always felt that various types of bark always impart the most color to the water over almost any other materials.

"Skyfruit Pods" 

These are very interesting, woody pods, derived from the outer "valve" of the fruit of the Swietenia macrophylla tree, which hails from a wide range of tropical locales (although native to Brazil), and are just the sort of thing you'd find floating or submerged in a tropical jungle stream. Often called "Skyfruit" by locals in the regions in which they're found because they hang from the trees- a name we fell in love with!

These botanicals can leach a terrific amount of tannins, akin to a similar-sized piece of Mopani wood or other driftwood. They are known to be full of flavonoids, saponins, and other humic substances, which have known positive health effects on fishes. Like bark, it lasts a good long time and recruits some biofilms and fungal growths for good measure.

Live Oak Leaves/Magnolia Leaves 

Despite their humble North American origins, these leaf types impart more color, ounce per ounce, than just about any of our fave tropical leaves. And they both last very long time...Like, I've had specimens of live oak leaves stay intact for several months!

It's really important to think of leaves as not just a "coloring agent" for your water, but as a sort of biological support mechanism for your burgeoning ecosystem. They actively recruit fungi, bacterial biofilms, and other microorganisms which enrich the overall aquatic environment in your tank.

 

 

Cones 

Alder cones  (Aalnus glutinosa and Alnus incana)  and Birch cones (Betula occidentalis), have  been widely utilized by aquarium hobbyists in Europe for some time. Betta and ornamental shrimp breeders are fond of the tannins released into the water by these cones, and their alleged anti fungal and antibacterial properties. There has also been much study by hobbyists about the pH reduction attributes of these cones, too.

A study done a few years back by a Swedish hobbyist using from one to six cones in a glass containing about 10 ounces of tap water, with a starting ph of around 8.12, was able to affect a drop to 6.74 with one cone after about two weeks, 4.79 with 2 cones after two weeks, and an amazing 3.84 with 6 cones after the same time period! The biggest part of the drop in pH occurred in the first 12 hours after immersion of the cones!

Now, I'm the last guy to tell you that a bunch of cones is the perfect way to lower pH, but this and other hobby-level studies seem to have effectively have demonstrated their ability to drive pH down in "malleable" (soft) water...

 Coconut-based products (Coco Curls, "Fundo Tropical", "Substrato Fino")

There's something about coconuts...The materials which are derived from the husks of coconuts seem to produce a significant amount of tannins and impart color to the water. Of course, "Substrate Fino" and "Fundo Tropical" are smaller, or finer-textured materials which work primarily as "substrate enhancers", and not strictly as "color-producing agents", because there is an initial "burst", which subsides over time. 

Now, one of the novel applications for these finer botanical materials to take advantage of their color producing ability is to place them in a fine mesh filter bag and allow water to flow around or through them, like filter media. Essentially, a more sustainable alternative to the old peat moss trick...

Oak Twigs

For an interesting look and some nice color, I'm a big fan of oak twigs. Oak has a nice bark which imparts a deep brownish/yellow color to the water and it's quite distinctive. There is a reason why our  "Twenty Twigs" packs are pretty popular, and it's not just because you get a bunch of cool sticks!

When mixed with leaves and/or other botanical materials, not only do you get an incredible "framework" for a cool ecosystem, you get an incredible aesthetic as well!

Now, this is an absolutely cursory list.. I could have easily listed 10 or more items. No doubt, some of you hardcore enthusiasts are screaming at your screens now: "WTF Fellman, you didn't include_______!"

And of course, that's the beauty of natural materials...There are numerous options!

Another note on the colors to expect from various botanical materials. As you might suspect, many of the lighter colored ones will impart a correspondingly lighter tint to the water. And, some leaves, such as Guava or Loquat, also impart a  more yellowish or golden color to the water, as opposed to the brownish color which Jackfruit and Catappa are known for. 

A lot of you ask about things that impact how long the water retains it's tint.

This kind stuff is a big deal for us- I get it! Many hobbyists who have perhaps added some catappa leaves, "blackwater extracts", or rooibos tea to their water contact me asking  stuff like why the water doesn't stay tinted for more than a few days. Now, I'm flattered to be a sort of "clearing house" for this stuff, but I must confess, I don't have all the answers.

So, "Why doesn't my water stay tinted, Scott?"

Well, I admit I don't know. Well, not for certain, anyways!

I do, however, have some information, observations, and a bunch of ideas about this- any of which might be literally shot to pieces by someone with the proper scientific background. However, I can toss some of these seemingly uncoordinated facts out there to give our community some stuff to "chew on" as I offer my ideas up.

Now, perhaps it starts with the way we "administer" the color-producing tannins. 

Like, I personally think that utilizing leaves, bark, and seed pods is perhaps the best way to do this. I'm sure that you're hardly surprised, right? Well, it's NOT just because I sell these material for a living...It's because they are releasing tannins, humic substances, and other compounds into the water "full time" during their presence in the aquarium as they break down. A sort of "on-board" producer of these materials, with their own "half life" (for want of a better term!).

And, they also perform an ecological role, providing locations for numerous life forms (like fungal growths) surface area upon which to colonize. They become part of the ecosystem itself. A few squirts of "blackwater extracts" won't do that, right?

The continuous release of tint-producing compounds from botanical materials keeps things more-or-less constant. And, if you're part of the "school" which leaves your botanicals in your aquarium to completely break down, you're certainly getting maximum value out of them! And if you are continuously adding/replacing them with new ones as they completely or partially break down, you're actively replenishing and adding additional "tint-producing" capabilities to your system, right?

There is another way to "keep the tint" going in your tanks, and it's pretty easy. Now, those of you who know me and read my rambling or listen to "The Tint" podcast regularly know that I absolutely hate shortcuts and "hacks" in the aquarium hobby. I preach a long, patient game and letting stuff happen in its own time...

Nonetheless, there ARE some that you can employ that don't make you a complete loser, IMHO.😆

When you prepare your water for water changes, it's typically done a few days to a week in advance, so why not use this time to your advantage and "pre-tint" the water by steeping some leaves in it? Not only will it keep the "aesthetics" of your water ( can you believe we're even talking about "the aesthetics of water?") consistent (i.e.; tinted), it will already have humic substances and tannins dissolved into it, helping you keep a more stable system.

Obviously, you'd still check your pH and other parameters, but the addition of leaves to your replacement water is a great little "hack" that you should take advantage of. (Shit, I just recommended a "hack" to you...)

It's also a really good way to get the "look" and some of the benefits of blackwater for your system from the outset, especially for those of you heathens that like the color of blackwater and despise all of the decomposing leaves and seed pods and stuff!

So, if you're just setting up a brand new aquarium, and have some water set aside for the tank, why not use the time while it's aging to "pre-tint" it a bit, so you can have a nice dark look from day one? It's also great if you're setting up a tank for an aquascaping contest or  other same-day club event that would make it advantageous to have a tinted tank immediately.

I must confess that yet another one of the more common questions we receive here from hobbyists is, "How can I get the tint in my tank more quickly?"- and this is definitely one way!

How many botanicals to use to accomplish this?

Well, that's the million dollar question.

Who knows?

It all gets back to the (IMHO) absurd "recommendations" that have been proffered by vendors over the years recommending using "x" number of leaves, for example, per gallon/liter of water. There are simply far, far too many variables- ranging from starting water chem to pH to alkalinity, and dozens of others- which can affect the "equation" and make specific numbers unreliable at best. 

We did, too, in the early days of Tannin. And it was kind of stupid really. There just is no hard-and-fast answer to this. Every situation is different. You need to kind of go with your instinct. Go slowly. Evaluate the appearance of your water, the behaviors of the fishes...the pH, hardness, TDS, nitrate, phosphate, or other parameters that you like to test for.

It's really a matter of experimentation.

I'm a much bigger fan of "tinting" the water based on the materials in the aquarium. Letting Nature have at it. The botanicals will release their "contents" at a pace dictated by their environment. And, when they're "in situ", you have a sort of "on board" continuous release of tannins and humic substances based upon the decomposition rate of the materials you're using, the water chemistry, etc.

Replacement of botanicals, or addition of new ones, as we've pointed out many times, is largely a subjective thing, and the timing, frequency, and extent to which materials are removed or replaced is dependent upon multiple factors, ranging from base water chemistry to temperature, to the types of aquatic life you keep in the tank (ie; xylophores like certain Plecos, or strongly grazing fishes, like Headstanders, will degrade botanicals more quickly than in a tank full of characins and such).

(The part where Scott bashes the shit out of the idea of using "blackwater extracts" and Rooibos tea. This could get nasty!)

If you haven't heard of it before, there is this stuff called Rooibos tea, which, in addition to bing kind of tasty, has been a favored "tint hack" of many hobbyists for years. Without getting into all of the boring details, Rooibos tea is derived from the Aspalathus linearis plant, also known as "Red Bush" in South Africa and other parts of the world. 

(Rooibos, Aspalathus linearis.  Image by R.Dahlgr- used under CC-BY S.A. 2.5)

It's been used by fish people for a long time as a sort of instant "blackwater extract", and has a lot going for it for this purpose, I suppose. Rooibos tea does not contain caffeine, and and has low levels of tannin compared to black or green tea. And, like catappa leaves and other botnaicals, it contains polyphenols, like flavones, flavanols, aspalathin, etc. 

Hobbyists will simply steep it in their aquariums and get the color that they want, and impart some of these substances into their tank water. I mean, it's an easy process. Of course, like any other thing you add to your aquarium, including leaves and botanicals, it's never a bad idea to know the impact of what you're adding. 

Like using botanicals, utilizing Rooibos tea bags in your aquarium requires some thinking, that's all. 

The things that I personally dislike about using tea or so-called "blackwater extracts" are that you are simply going for an effect, without getting to embrace the functional aesthetics imparted by adding leaves, seed pods, etc. to your aquarium as part of its physical structure and ecology, and that there is no real way to determine how much you need to add to achieve______.

Obviously, the same could be said of botanicals, but we're not utilizing botanicals simply to create brown water or to target specific pH parameters, etc. We're trying to create an ecology that is similar to what you'd see in such habitats in Nature.

Yet, with tea or commercial blackwater extracts, you sort of miss out on replicating a little "slice of Nature" in your aquarium. The building of an ecosystem.  Which is why we call this the botanical method. It's not a "style" of aquascaping! And of course, it's fine if your goal is just to color the water, but it's more of an aesthetically-focused aquarium at that point.

I also understand that some people, like fish breeders who need bare bottom tanks or whatever- like to condition water without all of the leaves and twigs and nuts we love. They want the humic substances and tannins, but really don't need/want the actual leaves and other materials in their tanks.

And, when it comes to tea and these commercial extracts, I don't think the stuff lasts all that long. I personally believe that the tint-producing tannins in "tea" are potentially taken up quickly by substrate materials, filter media, etc. And unless you're keeping tea bags in your tank on a continuous basis, you'll always experience some "color loss" after some period of time.

Yes it works to impart some color and tannins. Creating infusions or extracts is useful, if you understand their purpose and limitations. They have a place in the hobby for sure.

It's why we got into the game with our botanical-based "Shade" products. We're currently sold out and are working with our supplier on a reformulated version. Seems as though we need to make a "darker" mix!

On the other hand, if you're trying to replicate the look and function (and maybe some of the parameters) of THIS:

You won't achieve it by using THIS:

It's simply another shortcut.

Not good or bad. Just a way to get the end "effect" faster, and without the other collateral benefits we discussed.

And look, I understand that we are all looking for the occasional shortcuts and easier ways to do stuff. And I realize that none of what we proffer here at Tannin is an absolute science. It's likely more of an "art" at this point, with a little science behind it.

Think about it: There is no current way available to the hobby to test for "x" types or amounts of tannins (of which there are hundreds of types) in aquariums.  I mean, there are tannin test kits, but they're used for wine making and such...Perhaps there is some tangential application for our purposes, but I'm not really sure what practical information. we could extract from the results.

And, I have not found a study thus far which analyzed wild habitats (say, Amazonia) for tannin concentrations and specific types, so we have no real model to go on.

The best we can do is create a reasonable facsimile of Nature.

And, in Naturę, a lot of the tint in blackwater environments comes from dissolved fulvic and humic acids from...soils. Yeah, geology is the key, IMHO, to truly "realistic" blackwater habitats. This is why I've been very picky on sourcing the materials and figuring out recipes for our NatureBase sediment substrates. They are intended to support these types of systems.

Understanding substrates and their role in both the physical environment and the ecology of our aquariums is still a wildly under-appreciated concept in the aquarium hobby, IMHO. We'll keep coming back to this in the future, I'm certain.

And keeping the water tinted is something that many botanical method aquarists are interested in. This wonderful "collateral benefit" of our approach is something that's easy to get addicted to!

Now, all of these ideas are okay to impart some color to your water. Some do more, as we've discussed ad nauseam. And none of them will work to full advantage if your aquarium is removing them as fast as you're imparting them into the water. So, go easy on chemical filtration media like carbon. I didn't say NOT to use them...Just don't use a ton of them! Use less than what the manufacturer recommends. 

What about plants?

Well, I have a theory about plants and tannins...

First off, as you know by now, you absolutely can keep plants in blackwater aquariums. We've talked about this a million times over the years. And yet,  interestingly, you can't always keep "blackwater conditions" (at least, color-wise) in planted aquariums! There has been much geeky discussion on this topic.

Tannin are interesting things. Think about this:

Tannins are known to bind up heavy metals and minerals. The roots of aquatic plants prefer to take up bound-up minerals and metals...So, another theory of mine is that heavily planted tanks do actually remove some of the visual "tint" (ie; the tannins) from the water via uptake from their roots. 

Make sense? Maybe?

Okay, I could go on and on all day throwing out all sorts of theories and unsubstantiated (via lab tests and rigorous studies, anyways) ideas on this topic...But I think I gave you enough here to get the party started. I encourage you to do some homework. We need to ask these questions to people who really understand the chemistry here. I think that there might be some good answers out there.

And, back to the "color thing" to close on here...

I admit, visual "tint" is probably THE single most superficial aspect of what we experience with botanical-method aquariums- but the most obvious, and likely the most impactful to the casual hobbyist or observer.

It's just as important to understand the collateral benefits of utilizing botanical materials- a subject we've discussed dozens of times here. However, in the end, it's the look of your aquarium that is what you have to experience each and every day, and if having an understanding of which materials can bring you the aesthetic experience you're after in a more effective way- well, then this is a worthwhile discussion, right?

I think that it is.

Stay curious. Stay resourceful. Stay enthusiastic. Stay observant. Stay appreciative. Stay tinted...

And Stay Wet.

 

Scott Fellman

Tannin Aquatics  

Heading to the bottom...Again!

Time to hit on another of my fave topics regarding botanical method aquariums; one that we've talked about before- yet one that is still new and exciting to many of us, and perhaps clouded at times with a lot of misinformation, too.

We're talking about botanically-supplemented substrates!

For far too long in the aquarium hobby, I think that we've treated aquairum substrates as simply an afterthought. I mean, there are all sorts of sands and gravels on the market today, but I think that we sort of take them for granted- or at the very least, we treat them as a "requirement" when setting up a tank, and move on to other, more "exciting stuff": "Sand added, check. Time to select the wood!"

That sort of thing.

One of the most "liberating" things we've seen in the botanical-method aquarium niche is our practice of utilizing the bottom itself to become a feature aesthetic point in our aquariums, as well as a functional mechanism for the inhabitants.

"Oh, shit, he's talking about that 'functional aesthetic' thing again!"

Yeah. Yes I am. 😎

Because I think that there are a lot of "missed opportunities" to do something cool with substrates in our tanks. Opportunities to make it a much more important part of the aquarium. 

When you look at it from our rather biased perspective, and from a strictly aesthetic sense, the bottom itself becomes a big part of the aesthetic appeal of the aquarium. You may not focus on it, observationally, but it's hugely important. And of course, I see the bottom of the aquarium as more than just sand or whatever. Rather, it's a important component of the aquarium habitat, with the botanical materials placed upon or mixed into the substrate- or, in some cases, becoming the substrate!

These materials form an attractive, texturally varied "microscape" of their own, creating color and interest. In addition to be being comprised of the usual sands and gravels, we can be adding bits of botanicals, root pieces, twigs, leaves, etc. into the mix.

Why? 

Again, the focus isn't just on aesthetics. 

It's about creating a habitat for the fauna which help "run" our tanks!

Much like in Nature, the materials that we place on the bottom of the aquarium will become an active, integral part of the ecosystem. From a "functional" standpoint, bottoms comprised of supplemented with a variety of botanical materials form a sort of "in-tank refugium", which allows small aquatic crustaceans, fungi, and other microorganisms to multiply and provide supplemental food for the aquarium, as we've touched on before.

So, the idea of creating rich, diverse botanical-influenced substrates for the purpose of infusing tannins, humic substances, and other compounds- as well as creating a "matrix" for the growth and propagation of beneficial micro and microfauna is pretty appealing to me.

Using a botanically-infused substrate to create a unique, ecologically diverse, functional, and aesthetically interesting affect on the aquarium- even one that doesn't have aquatic plants in it- is a sort of different approach.

Functionality. Interest. Aesthetics. Stability. They're all there!

 

Nature provides no shortage of features which can provide inspiration for unique aquariums.

Think about the materials which accumulate on and in the substrates of natural aquatic habitats, and why they accumulate in the first place. Well, typically, in addition to soils and leaves, you'll see sediments, pieces of plant roots, bits of twigs and bark, and the occasional seed pod. Almost all of this material arrives in these bodies of water from the surrounding terrestrial environment.

Some of it is present on forest floors, and when nearby streams overflow, inundating the once dry floor, these materials become part of the aquatic environment, influencing both the structure and the ecology of the habitat. Other materials, like sediments, are the product of hydrology and erosion- rocks ground down over eons by water; or soils- which find their way into streams during periods of intense rain, with the resulting material distributed over vast distances by current.

The beauty of Nature is that She uses pretty much everything that is thrown at Her. Fishes and other organisms feed directly upon some of this material, or on the other life forms (small crustaceans, insects, fungal growths) which live among it. The bottom of streams and other becomes a vibrant, ecologically diverse habitat, which supports a tremendous amount of life at many levels.

And we just throw bag of aquarium sand or gravel on the bottom of our tanks...and move on!

Shit. Really?

Like, WTF is a matter with us fish geeks? There is HUGE opportunity here! We need to give a lot more thought to what goes on the bottom of our aquariums! Instead of becoming a literal "placeholder" in our tanks, substrate should become the ecological "backbone"- and a (functionally aesthetic) foundation of our miniature aquatic ecosystems- just like it is in Nature!

Now, the first "pushback" we hear from critics of this type of approach in aquariums is that it will result in all sorts of problems- ranging from suppressed pH to high levels of nitrates, or even pockets of hydrogen sulfide and other nasty stuff accumulating.

I think that this is an incredible over-reaction and grounded in not fully thinking through why we are creating substrates like this in the first place.

In Nature, the leaf litter "community" of fishes, insects, fungi, and microorganisms is really important to the overall tropical environment, as it assimilates terrestrial material into the blackwater aquatic system (and, by doing this, acts to reduce the loss of nutrients to the forest which would inevitably occur if all the material which fell into the streams was washed downstream...)

The key point: These materials foster the development of life forms which process it. Stuff is being used by life forms.

It's the same in our aquariums.

And bits of botanical materials and such not only provide a physical substrate upon which these organisms can grow and multiply as they process it- they provide a sort of "on board nutrient processing center" within the aquarium.

If you approach this "substrate enrichment" idea holistically, rather than just from some warped aesthetic mindset, creating and managing such a system is not at all difficult or dangerous. In fact, you don't really need to give it all that much thought in a well-managed aquarium, once it's set up.

I realize that experimenting with these unusual substrates requires not only a sense of adventure, a direction, and some discipline- but a willingness to accept and deal with an entirely different aesthetic than what we know and love. And this also includes pushing into areas and ideas which might make us uncomfortable, not just for the way they look, but for what we are told might be possible risks.

One of the things that many hobbyists ponder when we contemplate creating deep, botanical-heavy substrates, consisting of leaves, sediment, bark, and other botanical materials is the "buildup of hydrogen sulfide", CO2, and other undesirable compounds within the substrate.

Well, sure, I can't entirely "diss" fellow hobbyists for having this fear. It does make sense that if you have a large amount of decomposing material in an aquarium, then some of these compounds are likely to accumulate in heavily-"active" substrates. The big "bogeyman" that we all seem to zero in on in our "sum of all fears" scenarios - the one which keyboard warriors on the forums will pounce on- is an accumulation of deadly hydrogen sulfide, which results from bacterial breakdown of organic matter in the total absence of oxygen.

Let's think about this for just a second.

In a botanical bed with materials placed on the substrate, or loosely mixed into the top layers, will it all really "pack down" enough to the point where there is a complete lack of oxygen and we develop a significant amount of this reviled compound in our tanks? Are we managing tanks in such a way as to encourage no circulation whatsoever?

I think that we're more likely to see some oxygen in this layer of materials, and in fact, I can't help but speculate- and it IS just speculation- that actual de-nitirifcation (nitrate reduction), which lowers nitrates while producing free nitrogen, might actually be able to occur in a "deep botanical" bed.

And it's certainly possible to have denitrification without dangerous hydrogen sulfide levels. As long as even very small amounts of oxygen and nitrates can penetrate into the substrate this will not become an issue for most systems. I have yet to see a botanical-method aquarium where the material has become so "compacted" as to appear to have no circulation whatsoever within the botanical layer.

Now, sure, I'm not a scientist, and I base this on close visual inspection of numerous aquariums, and the basic aquarium-standard chemical tests I've run on my systems under a variety of circumstances. As one who has made it a point to keep my botanical method aquariums in operations for very extended time frames, I think this is significant. The "bad" side effects we're talking about should manifest over these longer time frames...and they just haven't.

Yeah- in my experience, based on literally a lifetime of playing with all sorts of combinations of materials in dozens and dozens of my aquariums' substrates ('cause I've always been into that stuff!), I cannot attribute a single environmental lapse, let alone, a "tank crash", as a result of such additions.

A well-managed substrate, in which uneaten food and fish feces are not allowed to accumulate to excess, and in which regular nutrient export processes are embraced, rather than decimated by constant interference (ie; siphoning) it's not an issue, IMHO. When other good practices of aquarium husbandry (ie; not overcrowding, overfeeding, etc.) are empIoyed, a botanically-"enriched" substrate can enhance- not inhibit- the nutrient processing within your aquarium and help maintain high water quality for extended periods of time.

Like many of you, I have always been a firm believer in some forms of nutrient export being employed in every single tank I maintain. Typically, it's regular water exchanges. Not "when I think about it', or "periodically", mind you.

Nope, it's weekly. 

Now look,  I'm not saying that you can essentially disobey all the common sense husbandry practices we've come to know and love in the hobby (like not overcrowding/overfeeding, etc.) and just change the water weekly and everything's good. And I'm not suggesting that the only way to succeed with adding botanical materials to the substrate is to employ massive effort at nutrient export; the system otherwise teetering on a knife's edge, with disaster on one side and success on the other. 

It's not that binary. 

Our aquariums are more resilient than that. If we set them up to be. Common sense aquarium management, with an eye towards how natural aquatic systems work, is key, IMHO.

Of course, an aquarium is NOT a stream, river, etc. However, the same processes and "rules" imposed by Nature that govern the function of these wild ecosystems apply to our little glass and acrylic boxes. It's simply a matter of nuance in management and understanding how these wild habitats work on a basic level.

I'd love to keep us in the mindset of thinking about our aquariums as little "microcosms", not just "aquatic dioramas."

Think about this: The idea of a substrate "enriched" with botanical materials is completely in line with the practices of a "dirted" planted aquarium. In our case, not only will there be an abundance of material for microorganisms and crustaceans to forage and multiply among, trace elements and essential plant nutrients will also be present in such a substrate. And, of course there will be the constant addition of tannins and humic substances into the water,  which provide many known benefits for fishes as well.

The best of both worlds, I think.

Again, it's not about creating a cool Instagram-ready "look."

It's about trying to create an entire aquatic ecosystem.

Embracing and fostering not just the look, but the very processes and functions which take place in natural aquatic systems. Is it as simple as crushing some leaves, adding some coconut-based material, covering it up with sand and you have an "instant tropical stream?" No, of course not. There is no such "magic bullet!" You need to look at things sort of "holistically"- with an eye towards nutrient export and long-term maintenance. 

For those of you who are adventurous, experimental, diligent, and otherwise engaged with managing and observing your aquariums, I think this process offers amazing possibilities. Not only will you gain some fascinating insights and the benefits of "on-board" nutrient export/environmental "enrichment"- you will also get the aesthetics of a more natural-looking substrate as well. (Let's face it, no matter how "function first" we feel that we are, everyone likes a nice-looking aquarium, right?)

 

So, the best way to "enrich" (for want of a better term) your substrate is to add the  botanical materials and sediments before you fill the tank up with water. In the case of leaves, bits of botanicals, etc., you'd want to have boiled/steeped them previously, so that they are rid of any surface contaminants, and to assure that their tissues are saturated enough to get them to sink immediately upon submersion.

There is no set "process" for this, other than to mix these materials into the upper layers of substrate as you add them. You will just sort of know when you've achieved the look and texture that pleases you (that's the "aesthetic" part!), and take comfort in knowing that just about any amount of these materials that you're adding to your system will help accomplish the "functional" aspect.

Once your substrate is in place, Nature takes over and the materials develop that lovely "patina" of fugal growth, biofilms and microbial colonization, and start breaking down. Some may be moved about by the grazing activities of resident fishes, or otherwise slowly redistributed around the aquarium.

A literal "active substrate", indeed! Yet, something that is fascinating and beautiful for those who give the idea a shot!

 At this point, I have to admit that there are many hobbyists who will never find any sort of appeal whatsoever in a botanically-enriched substrate, dark and complex, filled with all sorts of "stuff" besides just sand. The so-called "Nature Aquarium" cult crowd, or the truly "artistic" aquascaping people, for example, will likely never approve of this idea, because it looks "dirty" to them, and because some of the aesthetic and management "work" is being "ceded" to Nature. They need to be in control.

I admit, the simple practice of adding "botanical stuff" into our aquariums is not some "high concept thing." However, the impacts on the water chemistry and overall aquatic environment- not to mention, on our fishes- are profound, fascinating, and real!

Being careful and taking the time to clean, prepare, and add botanicals to your aquarium in a measured manner always yields a better outcome. Going slowly also gives you the opportunity to address any issues that you might have before they become critical, especially when you're experimenting with some of these ideas.

It just makes sense to be patient. The rewards are so great.

From a maintenance standpoint, it's pretty straightforward. You monitor your environmental parameters regularly, and conduct routine water exchanges, taking care not to siphon aggressively from the substrate. You simply don't want to disrupt the very processes within the substrate that you're trying to foster. And trust me, your fishes will spend a lot of time foraging among it.

Much like what occurs spontaneously in Nature, the materials that we deliberately place on the bottom of the aquarium will become an active, integral part of the ecosystem. 

Like so many things we discuss here, I admit that simply don't have all the answers about every aspect of botanically-supplemented substrates. There is a ton to learn! That's part of the joy of this process- sort of figuring out why and how it works as you're enjoying the success!

Playing with ideas like botanically supplemented substrates truly pushes the boundaries between what we do al the time in the hobby, and those outer regions where few have tread before. There will be challenges, discoveries..and rewards for taking this road less travelled.

And that's part of the fun, isn't it?

Stay creative. Stay brave. Stay curious. Stay diligent...

And Stay Wet.

 

Scott Fellman

Tannin Aquatics 

Along the way.

Our approach to aquarium keeping is as much a "mindset" as it is a practice. And, although the practical techniques are relatively easy to grasp and execute, the philosophical components can be confusing and seem a bit contradictory at times.

We preach radical patience, yet completely embrace the idea of dramatically changing things within the greater "mindset."

Huh? Wtf?

Yeah, you should just do what feels right to you.

And sometimes, that means creating an aquarium which doesn't look anything like you'd want it to until long after it's been established. Other times, it means tearing stuff apart immediately and "re-directing" your tank based on a different vision.

Yet, I always urge you to take a slightly longer view of what''s going on in your tank. Not to rush to completely tear your aquarium apart just because it doesn't seem to be getting to where you want it to go right after you set it up.

Stuff takes time.

Looking back on some of my favorite tanks that I've executed in the past few years, it becomes increasingly obvious to me that these systems really didn't completely hit that "look and feel" that I want until long after they'd evolved naturally...however long that took. It seems that , in the botanical-method aquarium, stuff needs to acquire a "patina" of biofilm, a "stain" from the tannins, and decomposition of botanical materials needs to really begin before one of these systems turns "functional" as well.

That's part of why using aesthetics only as an evaluation criteria for a successful botanical-method aquairum falls a bit short, IMHO.

I mean, every new botanical-method tank likely looks cool to a broader swatch of the aquarium world from day one, if you're just using superficial aesthetics as your metric...But the long-established ones stand out for what they really are. After 4-6 months, that's when things get really special. After Nature has done a lot of the real "work" on the tank.

The decomposition of materials in water impacts our aesthetics greatly, as we all know by now. And that is what's so intriguing. The crisp leaves and dry, lifeless twigs that you submerge will evolve into a dynamic, ever-changing microcosm.

Every tank can get there.

Simply by exercisng patience, and letting your aquarium be.

I've long held that perhaps my fave botanical-method aquarium of all was the one I did about 3 years ago..an aquarium utilizing mangrove wood, extensive leaf litter, and catappa bark throughout. This is probably the only tank in recent years that I've truly regretted changing and moving on from! 😂 

I knew what it was I wanted from the tank at the start, but it didn't look like much at first...It would have tested a lot of people's faith if they saw it in it's early stages! 

It literally looked like shit for the first couple of months of it's existence: Slightly tinted water, a contrived-looking "campfire-like" wood stack, bare sand, and mostly intact botanical materials. I had to do a bunch of "iterations" with the hardscape to get it where I wanted it. It looked quite "contrived" at points, but I knew instinctively that if I waited it out, let Nature do Her thing- that the potential was huge in this tank.

 

Sure enough, a few months in, biofilms started forming. The wood acquired that "patina" we talk about so much. Leaves and botanicals broke down...And the water took on perhaps the most earthy-looking, deeply mysterious color I've seen in a botanical-influenced blackwater aquarium.

By some standards, the water in the tank could be described as almost "turbid"- taking on an appearance as though there were fine materials in the water column. Yet, the tank had a real magical appearance with the lighting; the fishes were as colorful, relaxed and happy as any I've ever seen, and the water parameters were spot-on and consistent for as long as the tank was set up.

The essence of  "wabi-sabi", for sure. Transience, the ephemeral aspects of our botanicals...the wonders of Nature, embraced.

It just took a little time.

I could have "intervened" at a number of junctures- trying to "circumvent" these aesthetic "deviations" while the tank was evolving. However, I knew not to. I knew that the long-term gains from letting this system evolve would far exceed any "relief" I'd gain from siphoning out the biofilms, removing decomposing leaves, and clearing the water.

And, as usual- Nature delivered...because I didn't get in Her way.

We've done this numerous times with similar results. Inauspicious starts.

Botanical-method aquariums typically require more time to evolve than more "conventional" aquariums do. They are dependent upon the development of a specialized ecology, which includes fostering organisms like fungal growths and biofilms.This process can be "expedited" or manipulated a bit, but to achieve truly meaningful and beneficial results, you just can't rush stuff! 

You can't interrupt it, either.

When you do, as we've learned, results can be, well- "different" than they would be if you allow things to continue on at their own pace. Not necessarily always  "bad"- just not as good as what's possible if you relax and let Nature run Her course without interruption. Following a plan is never a bad idea; it can lead to some exciting destinations. 

 

However, the ability to "pivot" and "go with the flow" is really important, too.

It's not always a bad idea to switch things around if you're suddenly inspired to do so. What I hate to see is when hobbyists attempt to "intervene" on the processes which are occurring in the tank- like the recruitment of biofilms and fungal growths, the breakdown of leaves, etc. THAT'S a problem, imho.  You can change the "overall theme" without irrevocably interrupting Nature's processes.

Yeah, there IS a certain kind of "intervention" which I occasionally embrace myself. As I've previously discussed here, on occasion, I'll start to execute on an idea I've had, and very early (or sometimes, not so early) in the process, I'll completely lose interest in it for whatever reason (it can be anything from "not feeling it!" to "I hate that I can't hide that heater!"), and the desire to abort and move on to something else on my "to do list" beckons.

In general, however, I play a really long game.

One which acknowledges that the fact that our botanical-method aquariums evolve over very long periods fo time, not reaching the state that we perhaps envisioned for many months. My actions reflect this mindset. Unless there is some major emergency, about the only thing that I might do is to add a few more botanicals, re-arrange some wood, or just wait it out.

Of course, if you really are "not feeling it" (it happens!), does it mean tearing the whole thing apart and starting over?

No!

You can change the "look" or aesthetic direction of an aquairum- fairly significantly- without disrupting its function.

One of the things I've done a lot in recent years when making big changes to aquariums is to keep the substrate layers from my existing tanks and "build on them."  It makes a ton of sense, really. Why waste this goodness, just because the "theme" of the "new" tank is different than the existing one?  

Your South American-themed tank won't be that much different if you change up the "hardscape" to turn it into s Southeast Asian-themed tank, while leaving the substrate layer intact, right?

In other words, I'm taking advantage of the well-established substrate layers, complete with their sediments, decomposing leaves and bits of botanicals, and simply building upon them with some additional substrate and leaves. I've done this many times over the years- and I'm sure a lot of you have, too-it's hardly a "game-changing" practice, but it's something not everyone talks about.

I believe that preserving and building upon an existing substrate layer provides not only some biological stability (ie; the nitrogen cycle), but it has the added benefit of maintaining some of the ecological diversity and richness created by the beneficial fuana and the materials present within the substrate. 

I know many 'hobby old timers" might question the safety- or the merits-of this practice, mentioning things like "disturbing the bacterial activity" or "releasing toxic gasses", etc. A lot of 'em would rather have you simply remove this stuff altogether. It's "all or nothing" for them! I'm not sure how leaving the substrate layer intact is problematic. It doesn't "die." I believe that particular belief is steeped in "aquarium mythology", conflates a lot of different ideas and topics, and has generally been misapplied and misunderstood over the years.

I simply have never experienced any issues of this nature from this practice. Well maintained systems generally are robust and capable of evolving from such disturbances. And we're not really "disturbing" the substrate when we preserve it, are we? Moving around a few pieces of wood or rock might cloud the water a bit, but it's not wholesale disturbance of the substrate.

I see way more benefits to this practice than I do any potential issues.

Since I tend to manage the water quality of my aquariums well, if I say so myself, I have never had any issues, such as ammonia or nitrite spikes, by doing this- in fresh or saltwater systems. It's a logical way of maintaining stability and continuity- even in an arguably disruptive and destabilizing time!

This idea of a "perpetual substrate"- keeping the same substrate layer "going" in successive aquarium iterations- is just one of those things I believe that we can do to replicate Nature in an additional way.

Huh?

Well, think about it for just a second. In Nature, the substrate layer in rivers, streams, and yeah, flooded forests and pools tends to not completely wash away during wet/dry or seasonal cycles.

Oh sure, some of the material comprising the substrate layer may get carried away by currents or other weather dynamics, but for the most part, a good percentage of the material- and the life forms within it- remains when the water recedes. Wind and weather add additional materials to the now terrestrial environment, which become part of the aquatic habitat when the waters return.

So, by preserving the substrate from the previous iteration of your aquarium, and perhaps "refreshing" it a bit with some new materials (ie; sand, sediment, gravel, leaves, and botanicals), you're essentially mimicking some aspects of the way Nature functions in these wild habitats!

And, from an aquarium management perspective, consider the substrate layer a living organism (or "collective" of living organisms, as it were), and you're sure to look at things a bit differently next time you "re-do" a tank!

I suppose, one could view the process of "perpetuating" the substrate almost like persuing "eternal youth"- it's not entirely possible to achieve, but you can easily embrace the idea of renewal and continuity within your aquarium. It's a very natural process. Perhaps it's even beneficial in some way over the long term?

Things change in Nature, some things are utilized elsewhere, and other things are  preserved in situ. Nothing goes to waste.

Rather, stuff gets "folded" into the changing ecosystem. Leaves on the forest floor become a lush ecological niche for fungal growth and bacteria, and a grazing substrate for fishes when submerged. Tree branches become "attachment points" for epiphytic plants, sponges, and other aquatic life forms.

Nature is very efficient. We should take a cue from Her! "Disruption" is often a form of renewal and evolution in Nature.

Patience, as always, is the key ingredient here. Of course, this is a hobby, and it should be fun...and you should feel free to change stuff up if it's not. However, make it a point to consider your actions in the "big picture", and it takes on a greater significance.

You need to have an understanding that you're creating a dynamic environment, not simply an "aquascape." And it's constantly evolving- even when you're not ripping it apart!  It's anything but "static"-sort of like a planted aquarium, but in reverse (rather than plants growing, the botanicals are, for want of a better word "diminishing")! At any given time, you'll have materials like leaves in various states of decomposition, seed pods, slowly softening, breaking down, and recruiting biofilms and a "patina" of  fungal growth.

It begs the most fundamental of questions about our botanical method practice:

What happens over time in a botanical method aquarium? What changes occur along the way?

Well, typically, at its simplest, as most of you who've played with this stuff know, the botanicals will begin to soften and break down. Botanical materials are the very definition of the word "ephemeral." Nothing lasts forever, and botanicals are no exception! Pretty much everything we utilize- from Guava leaves to oak twigs- starts to soften and break down over time.

Most of these materials should be viewed as"consumables"- meaning that you'll need to replace them over time if you want maintain some environmental consistency. Again, perfectly analogous to what occurs in Nature.

You're not an "aquascaper" in the classic hobby sense when you play with these types of systems. Rather, you're a a sort of "superintendent" to Nature, helping Her do what she has done for eons. You're not simply an idle "passenger," either- you play an active role in conceiving, setting up, and maintaining such a system. You need to take some cues from Nature, and that often means simply standing by and observing as she does Her work and goes through Her process.

You learn. You evolve with your aquarium, on a very real level. 

Sometimes, it requires intervention on your part- at least in your own mind, perhaps. Other times, it simply involves sitting back, letting things unfold, and observing patiently.

Watching a display aquarium evolve and sort of "find itself" naturally over time is proving to be one of the most enjoyable discoveries I've made in the hobby in decades. It's a mindset that I actually had in my youth- by necessity, because I had very limited resources except for time- yet lost as I grew into adulthood and "evolved" in the hobby. With more skills and economic resources, I could "do more"- but the reality is that it wasn't always the right thing.

It took me a few decades after hitting so-called "advanced" hobbyist status before it really hit me that, by simply studying the function of natural ecosystems, all of the answers I needed to be successful as an aquarist were right there! I just needed to figure out which questions to ask.

I'm still deep in that process, decades later! 

By understanding that my aquariums are governed by the same "laws" which apply to natural aquatic ecosystems, and developing and following simple practices and husbandry routines to embrace this, and monitoring what's occurring in the tank (as opposed to constantly trying to intervene to "pre-empt" what we in the hobby have commonly perceived to be problems), I've personally had more beautiful, healthy and stable aquariums, and...more success than ever before.

Accepting that there is most definitely an elegant, yet complex ecological "dance" in our aquariums, and becoming an "active monitor" instead of an "active intervener" has added an enjoyable and rewarding aspect to my love of the hobby.

I think that this approach to the "dance" not only makes you a more engaged hobbyist, it gives you a remarkable appreciation for the long term evolution of an aquarium; an appreciation for the pace by which Nature operates, and the direction in which your aquarium ultimately goes.

By doing this, you get the enjoyment of seeing the "evolution" every day! Observing and enjoying the subtle nuances of your aquarium at every stage of its existence. With my "go slow" mindset and practice, the differences are subtle in the short term- the "payoffs" really more apparent over the longer term. 

Again, it's okay to make changes- even significant ones- to the "theme" of your aquarium. However, it's simply not good practice to interfere with the processes which allow it to become what Nature ( and YOU, too, if you're honest with yourself) wants it to become.

I know, it does feel a bit "yin" and "yang"- like I'm pulling from both sides- telling you, on one hand, that it's okay to make significant changes to a tank, while simultaneously urging you to deploy extreme patience and an almost "sit back and relax" approach...These seemingly diametrically opposite actions actually work really well together when you have the "common denominator" of good intentions, vision, careful actions, and an appreciation for what Nature can do if we let Her.

This philosophy, like so many things I ask you to consider here- doesn't always seem to make any sense.

Until it does.

Be kind to yourself- and to Nature.

Trust that She'll guide your aquarium effectively along the way to its ultimate potential. She won't let you down. Even if you take a slight detour now and again.

Stay confident. Stay observant. Stay curious. Stay patient....

And Stay Wet.

 

Scott Fellman

Tannin Aquatics 

 

 

 

For the love of weird substrates...

One of the "cornerstones" of our botanical-method aquarium practice is the use of substrate. Specifically, substrate materials which can influence- or make it easier to influence- water chemistry in the aquarium, as well as to help foster a "microbiome" of small organisms which will provide ecological diversity for the system.

Substrates, IMHO, are one of the most often-overlooked components of the aquarium. We tend to just add a bag of  "_____________" to our tanks and move on to the "more exciting" stuff like rocks and "designer" wood. It's true! Other than planted aquarium enthusiasts, the vast majority of hobbyists seem to have little more than a passing interest in creating and managing a specialized substrate or associated ecology.

 

A real pity, especially for those of us who are interested in botanical-method aquariums, which replicate natural aquatic habitats where soils and geology play a HUGE role in influencing the environmental parameters of these ecosystems. And in the hobby, we've largely overlooked the benefits and possibilities which specialized substrates can offer.

So I started to experiment with materials to recreate some of the characteristics of wild aquatic habitats which fascinated me. And an obsession was born.

I started playing with substrates mainly because I couldn't find exactly what I was looking for on the market. This is not some indictment of the major substrate manufacturers out there...I LOVE almost all of them and use and happily recommend ones that I like. I'm obsessed with substrates. I think that the companies which produce them are among the coolest of the cool aquatics industry brands. If I wasn't doing this botanical thing with Tannin, I'd probably have started a company that specializes in substrates for aquariums. Seriously.

And the fact is, the major manufacturers need to market products that more than like 8 people are interested in. It's unreasonable to think that they'd devote precious resources to creating a product that would be geared to such a tiny target. 

And of course, being one of those 8 people who are geeked-out about weird substrates, I decided that I'd "scratch my own itch" (as we did with the botanical thing..) and formulate and create some of my own. Thus, the NatureBase product line was born!

I realized that the specialized world which we operate in embraces some different ideas, unusual aesthetics, and is fascinated by the function of the environments we strive to replicate. These are important distinctions between what we are doing with substrates at Tannin, and what the rest of the aquarium hobby is doing.

Our NatureBase line is not intended to supersede or completely replace the more commonly available products out there as your "standard" aquarium substrate, because: a) they're more expensive, b) they're not specifically "aesthetic enhancements", c) they are not intended to be planted aquarium substrates, and d) because of their composition, they'll add some turbidity and tint to the aquarium water, at least initially (not everyone could handle THAT!)

So, right there, those factors have significantly segmented our target market...I mean, we're not trying to be the aquarium world's "standard substrate", they weren't formatted to grow aquatic plants, we're not marketing them just for the cool looks, and we can't emphasize enough that they will make your water a bit turbid when first submerged. If you have fishes which dig, or which like to "work" the substrate, you may see a near-continuous turbidity in your aquarium!

Oh, joy.

Those factors alone will take us out of contention for large segments of the market!

This is important to grasp.

I mean, these substrates are intended to be used in more natural, botanical-style/biotope-inspired aquariums. Our first two releases, "Igapo" and "Varzea", are specific to the creation of a type of "cyclical" terrestrial/aquatic feature. They do exactly what I wanted them to do, and they were specifically intended for use in specialized set ups, like the "Urban Igapo" idea we've been talking about for a long time here, as well as brackish water mangrove environments, etc.

Let's touch on the "aesthetic" part for a minute.

Most of our NatureBase substrates have a significant percentage of clays and sediments in their formulations. These materials have typically been something that aquarists have avoided, because they will cloud the water for a while, and often impart a bit of color. We also have some botanical components in a few of our substrates, because they are intended to be "terrestrial" substrates for a while before being flooded...and when this stuff is first wetted, some of it will float.

And that means that you're going to have to net it out, or let your filter take it out. You simply won't have that "issue" with your typical bag of aquarium sand!

Shit, you're probably just frothing right now, waiting to cloud and dirty up your aquariums with this stuff, huh?

No?

I can't for the life of me figure out why not? ;)

Remember, some of these substrates were formulated for a very specific purpose: To replicate the terrestrial soils which are seasonally inundated in the wild. As such, these products simply won't look or act like your typical aquarium substrate materials!

Scared off completely yet? I hope not.

Why include sediments and clays in our mixes? 

Well, for one thing, sediments are an integral part of the natural substrates in the habitats from which our fishes come. So, they're integral to our line. In fact, I suppose you'd best classify NatureBase products as "sedimented substrates."

Think about this: Many of our favorite habitats are forest floors and meadows which undergo periodic flooding cycles in the Amazon, which results in the creation of aquatic habitats for a remarkable diversity of fish species.

Depending on the type of water that flows from the surrounding rivers, the characteristics of the flooded areas may vary. Another important impact is the geology of the substrates over which the rivers and streams pass. This results in differences in the physical-chemical properties of the water.

In the Amazon, areas flooded by rivers of black or clear waters, with acid pH and low sediment load, in addition to being nutritionally poor, are called “igapó."

The flooding often lasts for several weeks or even several months, and the plants and trees need special biochemical adaptations to be able to survive the lack of oxygen around their roots. We've talked about this a lot here over the years.

 

Forest floor soils in tropical areas are known by soil geologists as "oxisols", and have varying amounts of clay, sediments, minerals like quartz and silica, and various types of organic matter. So it makes sense that when flooded, these "ingredients" will have significant impact on the aquatic environment. This "recipe" is not only compositionally different than typical "off-the-shelf" aquarium sands and substrates- it looks and functions differently, too.

YOU DON'T RINSE THEM BEFORE USE!

You CAN wet them right away; you don't have to do a "wet/dry season" igapo-style tank with them.  However, you should be ready for some cloudy water for a week or more! And again, if you have fishes which like to "work" the substrate, it will be a near-constant thing, the degree to which it will be is based on the habits of the fishes you keep.

 

And that's where a lot of people will metaphorically "leave the room."Turbid, darker water is a guaranteed "freak out" for a super-high  high percentage of aquarists. 

So, yeah, you'll have to make a mental shift to appreciate a different look and function.

And many hobbyists simply can't handle that. I've been extremely up front with this stuff since the introduction of these substrates, to ward off the, "I added NatureBase to my tank and it looks like a cloudy mess! This stuff is SHIT!" type of emails that inevitably come when people don't read up first before they purchase the stuff. (And trust me- the fact that you're even reading this blog, or listening to this podcast puts you in the tiniest minority of aquarium hobbyists!)

Let's talk a bit about how to "live" with these substrates. 

There are a lot of different ways to use these substrates in all sorts of tanks. I mean, if you want some of the benefits and want to geek out and experiment with them, you can use a "sand cap" of whatever conventional substrate you prefer on top, and likely limit the turbidity somewhat, much like the practice of aquarists who employ "dirted" substrates do.

Oh, and the plant thing...

We're asked a LOT if these substrates can grow aquatic plants. Now, although they were intended to facilitate the growth of terrestrial plants, like grasses, the fact is, both our customers and ourselves have seen pretty damn good plant growth in tanks using this stuff!

Our Igapo and Varzea substrates mimic sandy acidic soils that have a low nutrient content. And, as you know, the color and acidity of the floodwater is due to the acidic organic humic substances (tannins) that dissolve into it. The acidity from the water translates into acidic soils, which makes sense, right?

Now, I admit, I am NOT a geologist, and I'm not expert in soil science. I know enough to realize that, in order to replicate the types of habitats I am fascinated with, it required different materials. If you ask me, "Will this fish do well with this materials?" or, "Can I grow "Cryptocoryne in this?", or "Does this make a good substrate for shrimp tanks?" I likely won't have a perfect answer. Sorry.

Periodically, plant enthusiasts will ask me about the "cation exchange capacity" of our substrate. Cation Exchange Capacity (CEC) is the ability of a material to absorb positively-charged nutrient ions. This means the substrate will hold nutrients and make them available for the plant roots, and therefore, plant growth. CEC measures the amount of nutrients, more specifically, positivity changed ions, which a substrate can hold onto/store for future use by aquatic plants.

Thus, a "high CEC" is important to many aquatic plant enthusiasts in their work.  While it means that the substrate will hold nutrients and make them available for the plant roots. it doesn't indicate the amount of nutrients the substrate contains. 

For reference, scientists measure cation exchange capacity (CEC) in milliequivalents per 100 grams ( meq/100g).

As you might suspect, CEC varies widely among different materials. Sand, for instance, has a CEC less than 1 meq/100 g. Clays tend to be over 30 meq/100 g. Stuff like natural zeolites are around 100 meq/100g! Soils and humus may have CEC up to 250 meq/100g- that's pretty serious!

What nutrients are we talking about here? The most common ones which come into play in the context of CEC are iron, potassium, calcium and magnesium. So, if you're into aquatic plants, high CEC is a good thing!

Of course, this is where the questions arise around the substrates we play with.

It makes sense, right?

Our "Nature Base" substrates do contain materials such as clays and silts, which could arguably be considered "higher CEC" materials, because they're really fine- and because higher surface area generally results in a higher CEC. The more surface area there is, the more potential bonding sites there are for the exchange to take place. Alas, nothing is ever exactly what we hope it should be in this hobby, and clays are often not all that high in their CEC "ratings."

Now, the "Nature Base" substrates are what we like to call “sedimented substrates”, because they are not just sand, or pellets of fired clays, etc. They are a mix of materials, and DO also have some terrestrial soils in the mix, too, which are also likely higher in CEC. And no, we haven't done CEC testing with our substrates...It's likely that in the future, some enthusiastic and curious scientist/hobbyist might just do that, of course!

Promising, from a CEC standpoint, I suppose!

However, again, I must emphasize that they were really created to replicate the substrate materials found in the igapo and varzea habitats of South America, and the overall habitat- more "holistically conceived"-not specifically for plant growth. And, in terrestrial environments like the seasonally-inundated igapo and varzea, nutrients are often lost to volatilization, leaching, erosion, and runoff..

So, it's important for me to make it clear again that these substrates are more representative of a terrestrial soil. Interestingly, the decomposition of detritus and leaves and such in our botanical-method aquariums and "Urban Igapo" displays is likely an even larger source of “stored” nutrients than the CEC of the substrate itself, IMHO. Thus, they will provide a home for beneficial bacteria- breaking down organics and helping to make them more available for plant growth. 

Perhaps that's why aquatic plants grow so well in botanical-method aquariums?

Yeah, the stuff DOES grow aquatic and riparian plants and grasses quite well, in our experience! Yet, again- I would not refer to them specifically as "aquatic plant substrates." They're not being released to challenge or replace the well-established aquatic plant soils out there. They're not even intended to be compared to them!

Remember, our "Igapo" and "Varzea" substrates are intended to start out life as "terrestrial" materials, gradually being inundated as we bring on the "wet season." And because of the clay and sediment content of these substrates, you'll see some turbidity or cloudiness in the water. It won't immediately be crystal-clear- just like in Nature. That won't excite a typically planted aquarium lover, for sure. 

I can't stress it often enough: With our emphasis on the "wholistic" application of our substrate, our focus is on the "big picture" of these closed aquatic ecosystems.

I'll be the first to tell you that, while I have experimented with many species of plants, inverts, and fishes with these substrates, I can't tell you that every single fish or plant will like them. You'll simply have to experiment!

Well, shit- that's not something that you typically hear an aquarium hobby brand tell you to do with their products every day, huh? Like, I'm not going to make all sorts of generalized statements about everything I think that these products can do. It would be very unhelpful. I'd rather focus on how they perform in the types of systems in which they were intended to work in, and what the possible downsides could be!

The whole point here is that these substrates are perfect for a whole range of applications. They're not "the greatest substrates ever made!" or anything like that. However, they are super useful for replicating the soils of some of our favorite aquatic habitats. 

And for doing some of those geeky experiments that we love so much. So, that pretty much covers the "sedimented" substrate thing for now. Let's talk about "alternative" substrates for a bit...

PT.2 : "ALTERNATIVE SUBSTRATES" AND THE "DANGERS" FROM WITHIN? 

In my experience, and in the reported experiences from hundreds of aquarists who play with botanical materials breaking down in and on their aquariums' substrates, undetectable nitrate and phosphate levels are typical for this kind of system. When combined with good overall husbandry, it makes for incredibly stable systems.

I've been thinking through further refinements of the "deep botanical bed"/sand substrate relationship. I've been spending a lot of time researching natural aquatic systems and contemplating how we can translate some of this stuff into our closed system aquaria.

Now, I realize, when contemplating really deep aggregations of substrate materials in the aquarium, that we're dealing with closed systems, and the dynamics which affect them are way different than those in Nature, for the most part.

And I realize that experimenting with these unusual approaches to substrates requires not only a sense of adventure, a direction, and some discipline- but a willingness to accept and deal with an entirely different aesthetic than what we know and love. And this also includes pushing into areas and ideas which might make us uncomfortable, not just for the way they look, but for what we are told might be possible risks.

One of the things that many hobbyists ponder when we contemplate creating deep, botanical-heavy substrates, consisting of leaves, sand, and other botanical materials is the possible buildup of hydrogen sulfide, CO2, and other undesirable compounds within the substrate.

Well, it does make sense that if you have a large amount of decomposing material in an aquarium, that some of these compounds are going to accumulate in heavily-"active" substrates. Now, the big "bogeyman" that we all seem to zero in on in our "sum of all fears" scenarios is hydrogen sulfide, which results from bacterial breakdown of organic matter in the total absence of oxygen.

Let's think about this for just a second.

In a botanical bed with materials placed on the substrate, or loosely mixed into the top layers, will it all "pack down" enough to the point where there is a complete lack of oxygen and we develop a significant amount of this reviled compound in our tanks?  I just don't think so. I think that we're more likely to see some oxygen in this layer of materials, and I can't help but speculate- and yeah, it IS just speculation- that actual de-nitirifcation (nitrate reduction), which lowers nitrates while producing free nitrogen, might actually be able to occur in a "(deep) botanical" bed.

And it's certainly possible to have denitrification without dangerous hydrogen sulfide levels. As long as even very small amounts of oxygen and nitrates can penetrate into the substrate, this will not become an issue for most systems. I personally have yet to see a botanical-method aquarium where the material has become so "compacted" as to appear to have no circulation whatsoever within the botanical layer.

Now, sure, I'm not a scientist, and I base this on the management of, and close visual inspection of numerous aquariums, as well as the basic chemical tests I've run on my systems under a variety of circumstances. As one who has made it a point to keep my botanical-method aquariums in operation for very extended time frames, I think this is significant. The "bad" side effects we're talking about should manifest over these longer time frames...and they just haven't.

And then there's the question of nitrate. 

Although not the terror that ammonia and nitrite are known to be, nitrate accumulation is something a lot of hobbyists are concerned with. As nitrate accumulates, fish will eventually suffer some health issues. Ideally, we strive to keep our nitrate levels no higher than 5-10ppm in our aquariums.  

As a reef aquarist, I was always of the "...keep it as close to zero as possible." mindset, until I realized that corals just grow better with the presence of some nitrate! This was especially evident in my large scale coral grow-out raceways.

It seems that 'zero" nitrate is not always the most realistic or achievable target in a heavily-botanical-laden aquarium, although I routinely see undetectable nitrate reading in my tanks. You have a bit more "wiggle room", IMHO, however, before concern over fish health is a factor. Now, when you start creeping towards 50ppm, you're getting closer towards a number that should alert you.

It's not a big "stretch" from 50ppm to more potentially detrimental readings of 75ppm and higher...

And then you get towards the range where health issues could manifest themselves in your fishes. Now, many fishes will not show any symptoms of nitrate poisoning until the nitrate level reaches 100 ppm or more. However,  studies have shown that long-term exposure to moderate concentrations of nitrate stresses fishes, making them more susceptible to disease, affecting their growth rates, and inhibiting spawning in many species. 

At those really high nitrate levels, fishes will become noticeably lethargic, and may have other health issues that are obvious upon visual inspection, such as open sores or reddish patches on their skin. And then, you'd have those "mysterious deaths" and the sudden death (essentially from shock) of newly-added fishes to the aquarium, because they're not acclimated to the higher nitrate concentrations.

Okay, that's scary stuff. However, high nitrate concentrations are not only manageable- they're something that's completely avoidable in our aquairums.

Quite honestly, even in the most heavily-botanical-laden systems I've played with, I have personally never seen a higher nitrate reading than around 5ppm. Often, as I mentioned above, they're undetectibIe on hobby-level test kits. I attribute this to common sense stuff: Good quality source water (RO/DI), careful stocking, feeding, good circulation, not disturbing the substrate, and consistent basic aquarium husbandry practices (water exchanges, filter maintenance, etc.).

Now, that's just me.

I'm no scientist, certainly not a chemist, but I have a basic understanding of maintaining a healthy nitrogen cycle in the aquarium. And I am habitual-perhaps even obsessive- about consistent maintenance. Water exchanges are not a "when I get around to it" thing in my aquarium management "playbook"- they're "baked in" to my practice.

So yeah, although nitrate is something to be aware of in botanical-method aquariums, it's simply not an ominous cloud hanging over our success.

Relatively shallow sand or substrate beds seem to be optimal for denitrification, and many of us employ them for the aesthetics as well. Light "stirring" of the top layers, if you're concerned about any potential "dead spots" is something that is permissible, IMHO. Any debris stirred up can easily be removed mechanically by filtration, as mentioned above.

But that's it.

 

Of course, as we already discussed, you don't have to go crazy siphoning the shit (literally!) out of your sand every week, essentially decimating populations of beneficial microscopic infauna -or interfering with their function- in the process.

What I am starting to feel more and more confident about is postulating that some form of denitrification occurs in a system with a layer of leaves and botanicals as a major component of the tank.

Now, I know, I have little rigorous scientific information to back up my theory, other than anecdotal observations and even some assumptions. However, there is always an example to look at- Nature. 

Of course, Nature and aquariums differ, one being a closed system and the other being "open." However, they both are beholden to the same laws, aren't they? And I believe that the function of the captive leaf litter bed and the wild litter beds are remarkably similar to a great extent.

The thing that fascinates me is that, in Nature, leaf litter beds perform a similar function; that is, fostering biodiversity, nutrient export, and yes- denitrification. Let's take a little look at a some information I gleaned from the study of a natural leaf litter bed for some insights.

In a slow-flowing wild Amazonian stream with a very deep leaf litter bed, observations were made which are of some interest to us. First off, oxygen saturation was 6.7 3 mg/L (about 85% of saturation), conductivity was 13.8 microsemions, and pH was 3.5.

Some of these parameters (specifically the very low pH) are likely difficult to obtain and maintain in the aquarium, but the interesting thing is that these parameters were stable throughout a months-long investigation.

 

 

 

Microscopic investigation confirmed that the leaf litter was heavily populated with fungi and other microfauna. There was also a significant amount of fish life. Interestingly, the fish population was largely found in the top 12"/30cm of the litter bed, which was estimated to be about 18"/45cm deep. The food web in this type of habitat is comprised largely of fungal and bacterial growth which occurs in the decomposing leaf litter. 

Okay, I"m throwing a lot of information here, and doing what I hope is a slightly better-than-mediocre attempt at tying it all together. The principal assertions I'm making are that, in the wild, the leaf litter bed is a very productive place, and has a significant impact on its surroundings, and that it's increasingly obvious to me that many of the same functions occur in an aquarium utilizing leaf litter and botanicals.

"Enriching" a substrate with botanicals, or composing an entire substrate of botanicals and leaves is a very interesting and compelling subject for investigation by hobbyists.

So, three areas of potential investigation for us:

*Use of botanicals and leaves to comprise a "bed" for bacterial growth and denitrification.

*Understanding the chemical/physical impact of the botanical "bed" on an aquarium. (ie, pH, conductivity, etc.)

*Utilization of a botanical bed to create a supplemental food source for the resident fishes.

We've also touched on the idea of a leaf litter/botanical bed as "nursery" for fry, something more and more hobbyists/breeders are confirming is a logical "go-to" thing for them. 

Interesting semi-anecdotal observations from my friends in the know suggest that the biofilms for decaying leaves form a valuable secondary food for the fry of fishes such as Discus, Uaru, (after they’re done feeding on their parent’s exuded slime coat) and even Loricariid catfishes. And I've seen juvenile fishes  of a variety of species "appear" from my botanical-rich aquariums over the years, fat and happy, apparently deriving some nutrition from the fungi, bacteria, and small crustaceans which live in, on, and among the leaf litter bed.

My own experience with creating leaf-litter-bed-focused aquariums has proven that supplemental food production for the resident fishes is a real "thing" that we need to consider. It's a valid and very exciting approach to creating a functional closed aquatic ecosystem.

 

We talk about the concept of "substrate enhancement" or "enrichment" a lot in the context of aquatic botanicals (we tend to use the two terms interchangeably).

Again, we're not talking about "enrichment" in the same context as say, planted aquarium guys, with materials put into the substrate specifically for the benefit of plants. However, the addition of botanical and other materials CAN create a sort of organic "mulch" which benefits many aquatic plants! 

Rather, "enrichment" in our context refers to the addition of botanical materials for creating a more natural-appearing, natural-functioning substrate- one which provides a haven for microbial life, as well as for small crustaceans, biofilms, and even algae, to serve as a foraging area for our fishes and invertebrates.

We've found over the years of playing with botanical materials that substrates can be really dynamic places, and benefit from the addition of leaves and other materials. For many years, substrates in aquarium were really just sands and gravels. With the popularity of planted aquariums, new materials, like soils and mineral additives, entered into the fray.

With the botanical-method aquarium starting to gain in popularity, now you're seeing all sorts of materials added on and in the substrate...for different reasons of course.

I think the big takeaway is that we should not be afraid to experiment with the idea of mixing various botanical materials into our substrates, particularly if we continue to embrace solid aquarium husbandry practices.

In my opinion, richer, botanically-enhanced substrate provides greater biological diversity and stability for the closed system aquarium. 

Is it for everyone?

Not for those not willing to experiment and be diligent about monitoring and maintaining water quality. Not for those who are superficially interested, or just in it for the unique aesthetics it affords. 

However, for those of you who are adventurous, experimental, diligent, and otherwise engaged with managing and observing your aquariums, I think it offers amazing possibilities. Not only will you gain some fascinating insights and the benefits of "on-board" nutrient export/environmental "enrichment"- you will also get the aesthetics of a more natural-looking substrate as well.

Like so many things we do in our niche, the "weird" alternative and botanical-enriched substrate approaches are fascinating, dynamic, and potentially ground-breaking for the aquarium hobby. For the adventurous, diligent, and observant aquarist, they present numerous opportunities to learn, explore, and create amazing, function-first aquatic ecosystems.

Who's in?

Stay creative. Stay observant. Stay diligent. Stay thoughtful...

And Stay Wet.

 

Scott Fellman

Tannin Aquatics 

 

Throwing some light on blackwater...

It goes without saying that the single most important component of our aquariums is also the most obvious...water! As the literal bearer of life and the environment in which our fishes, plants, and other organisms thrive, it's fundamental. it's the reason we're drawn to fishes, not gerbils, Tarantula, or Mice- or whatever other pets people keep!

Yeah, we're into water!

And I dear say that we take it for granted a bit.

Now, sure, some hobbyist rightfully place the importance of good quality, properly-conditioned water at the very top of their "want list" of "Stuff" required for successful aquariums. These are often fish breeders and very serious hobbyists, who understand the fundamental importance of good water for their work.

Some of the most common questions we receive lately are "How much _______ do I need to get my water to look like________?" or "How much_______ is needed to lower the pH in my tank?" Or, "How much do I need to get a good amount of humic substances and tannins into my aquarium?"

I usually respond with a simple, "I don't know."

These are all really good questions. Logical. Important.  I kind of feel like many hobbyists are looking for a plug-and-play "formula" or "recipe" for how to accomplish certain water-conditioning tasks.

I totally get that. But the reality is...there IS no "recipe" for how to do this stuff.

And it sucks, I know.

"Why, Scott? I read that you can just add some of this blackwater extract that you can buy online, and maybe add some catappa leaves, and..."

Stop. STOP. Please, we're just making this painful.

Simply adding leaves or bottled extracts to your tap water isn't going to result in "Instant Amazon" or whatever. There are numerous complexities and nuances which contribute to these habitats that to simply recommend adding "X" to your water isn't the whole story.

There are so many variables in the equation that it's almost impossible to give a definitive answer. And yeah, us guys in the botanical biz haven't really helped the situation. Over the years, vendors who sold catappa leaves, for example, would recommend starting amounts ("three leaves per 15 liters of water" or whatever...) of botanical materials to use in aquariums.

I mean, we've sort of done it, too...And, although our recommended "dosage" of leaves was given for different reasons (to avoid adding too much material to your tank too quickly), the idea of a "recipe" in general is kind of delusional, IMHO.

Now, this was all well and good, but it's based on....what? I mean, is this based on how many leaves of _______ size that a typical hobbyist with a 10-gallon aquarium needs to get the water "looking brown?" Or to lower tap water with a starting pH of 7.4 and a KH of ___ to pH of 6.9? Or to impart "x" ppm of tannins or humic substances into this given quantity of water?

See? Add to this story the fact that you really can't soften water and make it more "malleable" by using botanicals or extracts alone, and you've got a good case for confusion! It's just not that simple.

Maybe we can gain a bit of understanding- or at least, an appreciation for the dynamics of this process, by looking once again to Nature.

Have you very thought about how water reaches all of the wild aquatic systems of the world? I mean, it's got to get there some way, right? So, how does it reach the ponds, lakes, streams, and rivers and forest floors of the world?

Well, some simply falls into the body of water directly from the sky, and that's that. Some is a result of other overflowing streams and rivers (like, ya' know- those flooded Igapo forests we talk about!). Inputs of precipitation falling over the area of an aquatic habitat are transferred to the habitat via a number of different pathways.

It's surprisingly complicated.

There's like a whole field of science devoted to studying this process! It's called Hydrology, and it's incredibly interesting...As fish geeks, we're probably already acquainted with this field of study, at least tangentially! 

So, water comes from a variety of sources, reaching a myriad of ecological niches. However, not all of the water has such an easy journey on its way into our favorite aquatic habitat!

Even in the case of rainwater, some of it simply lands on tree leaves in the surrounding area and evaporates. This is a process scientists call "interception", and accounts for the fact that not all water makes it to the ground. Water that does reach the ground enters the soil through a process called infiltration. slowly percolating down to soil areas known as the "saturated zone"- and as you'd imagine, this is where the fun really begins! (to a soil geologist, at least!)

The soil properties control the infiltration capacity; these include things like soil permeability, the presence of vegetation and plant roots, and how much water is already in the soil. Through what is known as "ground water flow", ultimately, the water finds it way into our favorite aquatic habitats. It's important to note that soil texture ( the relative proportion of sand, silt and clay particles within the mix) affects infiltration rates. 

Sandy soils like the "podzols", common to forested areas of South America that we've talked about have higher permeability than some clay-based soils. In some really arid areas a "crust" can form on the soil surface, decreasing the permeability. And of course, the thickness of the soil directly affects how much water the soil can actually absorb.

And, in many cases, the substrate composition and its relationship with water has direct impact on the life forms which inhabit these aquatic systems. In the case of some habitats, like vernal pools, which are filled with water seasonally, the substrate is of critical importance to the aquatic life forms which reside there.

Yeah, soils and geology are perhaps the primary driver of water composition in Nature. 

Let's talk more about "blackwater."

In a blackwater environment, the color is a visual indicator of an influx of dissolved materials that contribute to the "richness" of the environment. Indeed, a blackwater environment is typically described as an aquatic system in which vegetation decays, creating  tannins that leach into the water, making a transparent, acidic water that is darkly stained, resembling tea.

But, that's not the whole story, really.

It’s important to really try to understand the most simple of questions- like, what exactly is “blackwater”, anyways?

A scientist or ecologist will tell you that blackwater is created by draining from older rocks and soils (in Amazonia, look up the “Guyana Shield”), which result in dissolved fulvic and humic substances, present small amounts of suspended sediment, and characterized by lower pH (4.0 to 6.0) and dissolved elements, yet higher SiO₂ contents. Magnesium, Sodium, Potassium, and Calcium concentrations are typically very low in blackwater. Electrical conductivity (ORP) is also lower than in so-called "whitewater" habitats.

Tannins are also imparted into the water by leaves and other botanical materials which accumulate in these habitats.

 

The action of water upon fallen leaves and other botanical-derived materials leaches various compounds out of them, creating the deep tint that many of us are so familiar with. Indeed, this "leaching" process is analogous to boiling leaves for tea. The leached compounds are both organic and inorganic, and include things like tannin, carbohydrates, organic acids, pectic compounds, minerals, growth hormones, alkaloids, and phenolic compounds.

Most of the of the extractable substances in the surface litter layer are humic acids, typically coming from decaying plant material. Scientists have concluded that greater input of plant litter leads to greater input of humic substances into ground water.

In other words, those leaves that accumulate on the substrate are putting out significant amounts of humic acids, as we've talked about previously! And although humic substances, like fulvic acid, are found in both blackwater and clear water habitats, the organic detritus (you know, from leaves and such) in blackwater contains more extractable fulvic acid than in clearwater  habitats, as one might suspect!

The Rio Negro, for example, contains mostly humic acids, indicating that suspended sediment selectively adsorbs humic acids from black water.  The low concentration of suspended sediments in rivers like the Rio Negro is one of the main reasons why high concentrations of humic acids are maintained. With little to no suspended sediment, there is no "adsorbent surface" (other than the substrate of the river, upon which these acids can be taken hold of (adsorb).

When you think about it, all of this this kind of contributes to why blackwater has the color that it does, too. Blackwater in the Amazon basin is colored reddish-brown. Why? Well, it has  those organic compounds dissolved in it, of course. And most light absorbtion is in the blue region of the spectrum, and the water is almost transparent to red light, which explains the red coloration of the water!

And many of those organic compounds come from the surrounding land, as touched on above...

In summary, natural "blackwaters" typically arise from highly leached (tropical) environments where most of the soluble elements in the surrounding rocks and soils are rapidly removed by heavy rainfall. Materials such as soils are the primary influence on the composition of blackwater.

Leaves and other materials contribute to the process and appearance in Nature, but are NOT the primary “drivers” of its creation and composition.

 

So, right from the start, it’s evident that natural blackwater is “all about the soils…” Yeah, I'll repeat it again: It’s more a product of geology than just about anything else. 

More confusing, recent studies have found that most of the acidity in black waters can be attributed to dissolved organic substances, and not to dissolved carbonic acid. In other words, organic acids from compounds found in soil and decomposing plant material, as opposed to inorganic sources. Blackwaters are almost always characterized by high percentages of organic acids.

Despite the appearance, as a general rule, blackwater rivers are lower in nutrients than clear rivers. Wouldn't it be interesting, when contemplating more natural biotope/biotype aquariums, to study and take into consideration the surrounding geology and physical characteristics of the habitat?  Too recreate the habitat based on the soil or geological composition of the surrounding terrestrial environment?

As we know now, the influence of factors like soil, and the presence of terrestrial materials like seed pods, leaves, and branches play a huge role in the chemical composition and appearance-of the water. It's really no different in the aquarium, right?

Like so many things in nature, the complexity of blackwater habitats is more than what meets the eye. Chemically, biologically, and ecologically, blackwater habitats are a weave of interdependencies- with soil, water, and surrounding forest all functioning together to influence the lives of the fishes which reside within them. No single factor could provide all of the necessary components for fish populations to thrive.

To damage or destroy any one of them could spell disaster for the fishes- and the ecosystem which supports them. It is therefore incumbent upon us to understand, protect, and cherish these precious habitats, for the benefit of future generations. 

And with regards to our aquarium work?

Although there may even be breakthroughs in terms of blackwater extracts and additives coming to market, there are still a lot of questions that would have to be answered before we could simply state that "X" drops per gallon of such an such a formula would yield a specific outcome. This reminds me of the reef aquarium world more an more, lol.

So, if I've made any "argument" here, it's that this stuff is every bit as much of an "art"- in terms of aquarium keeping- as it is a "science." We will, at least for the foreseeable future, have to use the data we have available and formulate a best guess as to how much of what can give us some of the impacts we are interested in for our aquariums.

We simply can't authoritatively make blanket statements like, "You need to use "X" catappa leaves per gallon in order to recreate Rio Negro-like conditions in your aquarium!" We can't simply state that you can throw in some podzolic soil and achieve blackwater, either. There are many factors in play, as we've discussed here, right?

Marketing hyperbole aside, we really are sort of...guessing.

And that's certainly nothing to be discouraged about!

We, as a community, are getting deeper into the functional aspects of blackwater, botanical-style aquariums than ever before. More light is being shed on what's going on in both our aquariums and in the natural habitats we desire to replicate. We are learning more every day about how the presence of tannins and humic substances in our aquariums is affecting the health, longevity, and spawning behaviors of our blackwater fishes.

We're learning about the challenges and realities of managing blackwater systems over the long term- understanding the good, the bad, and the dangerous possibilities that are present when we experiment with these ideas.

There is much, much more work to be done..And a lot of talented hobbyists like yourself are out there on the front lines every day, contributing to the body of knowledge that will benefit the hobby for generations!

Stay persistent. Stay bold. Stay open-minded. Stay curious. Stay disciplined...

And Stay Wet.

 

Scott Fellman

Tannin Aquatics 

 

Behind the dynamics of the "Urban Igapo"

I've always been fascinated by environments which transform from dry, terrestrial ones to lush aquatic ones during the course of the year. I remember as a kid visiting a little depression in a field near my home , which, every spring, with the rains would turn into a little pond, complete with frogs, Fairy Shrimp, and other life forms. I used to love exploring it, and was utterly transfixed by the unique and dynamic seasonal transition.

The thrill and fascination of seeing that little depression in the ground, which I later learned was called a "vernal" or "temporal" pool by ecologists, never quite left me. As a fish geek, I knew that one day I'd be able to incorporate what I had seen into my fish keeping hobby...somehow.

About 5 years ago, I got a real "bug up my ass", as they say, about the flooded forests of South America. There is something alluring to me about the way these habitats transition between terrestrial and aquatic at certain times of the year. The migration of fishes and the emergence of aquatic life forms in a formerly terrestrial environment fascinates me- as does the tenacity of the terrestrial organisms which hang on during these periods of inundation. 

So, I began playing with aquariums configured to replicate the function and form of these unique habitats. I spent a lot of time studying the components of the Igapo and Varzea environments- the soils, plants, fauna, etc., and learning the influences which lead to their creation and function.  

Once I had a grasp of the way these dynamic ecologies work, the task of attempting to recreate them in the aquarium became more realistic and achievable. I realized that, although hobbyists have created what they call "Igapo" simulations in biotope contests for years, for example, it was always a representation of the "wet" season.  Essentially a living "diorama" of sorts. Not really a true simulation of the seasonal dynamics which create these habitats.

They were cool, but something was somehow missing to me. With those representations, you throw in some leaves, twigs, and seed pods, maybe a few plants, and call your tank a "flooded forest."  I mean, essentially a botanical-style aquairum, although the emphasis was on appearance, not function. That wasn't really that difficult to do, nor much of a advancement in the current state of the art of aquarium keeping. I could do that already. Rather, I wanted to recreate the process- all of it- or as much as possible- in my aquariums.

Thus, the idea of the "Urban Igapo"- a functional representation of a transitional aquatic habitat was born. 

The concept behind the "Urban Igapo" is pretty straightforward:

The idea is to replicate to a certain extent, the seasonal inundation of the forests and grasslands of of Amazonia by starting the tank in a 'terrestrial phase", then slowly inundating it with water over a period of weeks or more; then, running the system in an "aquatic phase" for the duration of the 'wet season", then repeating the process again and again.  

 

Because you can do this in the comfort of your own home, we called the concept the "Urban Igapo." About 2 years ago, we went more in depth with some of the procedures and techniques that you'd want to incorporate into your own executions of the idea.

 

As with so many things in the modern aquarium hobby, there is occasionally some confusion and even misunderstandings about why the hell we do this in the first place! 

Well, that's a good question! I mean, the whole idea of this particular approach is to replicate as faithfully as possible the seasonal wet/dry cycles which occur in these habitats. It starts with a dry or terrestrial environment, managed as such for an extended period of time, which is gradually flooded to simulate inundation which occurs when the rainy season commences and swollen rivers and streams overflow into the forest or grassland.

Sure, you can replicate the "wet season" only- absolutely. I've seen tons of tanks created by hobbyists to do this. However, if you want to replicate the seasonal cycle- the real magic of this approach- you'll find as I did that it's more fun to do the "dry season!"

Think of it in the context of what the aquatic environment is- a forest floor or grassland which has been flooded. If you develop the "hardscape" (gulp) for your tank with that it mind, it starts making more sense. What do you find on a forest floor or grassland habitat? Soil, leaf litter, twigs, seed pods, branches, grasses, and plants.

 Just add water, right?

Well, sort of.

Now, recently, one of my friends who was presenting his experiences with this approach was just getting pounded on a forum by some, well- let's nicely call them "skeptics"- you know, the typical internet-brave "armchair expert" types- about why you'd do this and how it can't lead to a stable aquarium and how it's "not a blackwater aquarium" (okay, it wasn't presented as such, but it could be...) and that it's just a "dry start" (Well, sort of, but you have to understand the concept behind it, dude), and that you don't need to do it this way and...well- that kind of stuff.

I mean, the full compliment of negative, ignorant, questions by people clearly frightened about someone trying to do something a little differently. In a typical display of online-warrior hypocrisy, one particularly nasty hack did not even bother to research the idea or think about what it was really trying to do before laying into my friend.

Apparently, for these people, there was a lot to unpack.

I mean, first of all, the idea was not intended to be a "dry start" planted tank. It just wasn't. I mean, it starts out "dry", but that's where the similarity ends. This ignorant comment is a classic example of the way some hobbyists make assumptions based on a superficial understanding of something.

We aren't trying to grow aquatic plants here. It's about creating a habitat of terrestrial plants snd grasses, allowing them to establish, snd then inundating the display. Most of the terrestrial grasses will simply not survive extended periods of time submerged. Now, you COULD add adaptable aquatic plants- there are no "rules"- but the intention was to replicate a seasonal dynamic. 

The other point, which is utterly lost on some people, is that establishing a "transitional" environment in an aquarium takes time and patience. One dummy literally called the process "complete nonsense" and a "waste of time." This is exactly the kind of self-righteous, ignorant hobbyist who will never get it. In fact, I'm surprised guys like that actually have any success at anything in the hobby.

Such a dismissive and judgmental attitude. 

To replicate this process is really not difficult. The challenging part is to separate what we are trying to do here from our preconceptions about how an aquarium should work. To understand that the resulting aquatic display won't initially look or function like anything that we're already familiar with.

While it superficially resembles the "dry start" method that many aquatic plant enthusiasts play with, it's important to remember that our goal isn't to start plants for a traditional aquarium. It's to establish terrestrial growth and to facilitate a microbiome of organisms which help create this habitat. It's to replicate, on some levels, the year-round dynamic of the Amazonian forests. We favor terrestrial plants- and grasses-grown from seed, to start the "cycle."

So, those of you who are ready to downplay the significance of experimenting with this stuff because "people have done 'dry start' planted tanks for years", take comfort in the fact that I recognize that, and acknowledge that we're taking a slightly different approach here, okay?

 

You'll need to create a technical means or set of procedures to gradually flood your "rainforest floor" in your tank, which could be accomplished manually, by simply pouring water into the vivarium over a series of days; or automatically, with solenoids controlling valves from a reservoir beneath the setup, or perhaps employing the "rain heads" that frog and herp people use in their systems. This is all very achievable, even for hobbyists like me with limited "DIY" skills.

You just have to innovate, and be willing to do a little busy work. You can keep it incredibly simple, and just utilize a small tank.

You must be patient.

And of course, there are questions. Here are some of the major/common ones we receive about this concept:

Does the grass and plants that you've grown in the "dry season" survive the inundation?

A great question. Some do, some don't. (How's that for concise info!). I've played with grasses which are immersion tolerant, such as Paspalum. This stuff will "hang around" for a while while submerged for about a month and a half to two months, in my experience, before ultimately succumbing. Sometimes it comes back when the "dry season" returns. However, when it doesn't survive, it decomposes in the now aquatic substrate, and adds to the biological diversity by cultivating fungi and bacteria.

You can use many plants which are riparian in nature or capable of growing emmersed, such as my fave, Acorus, as well as all sorts of plants, even aquatics, like Hydrocotyle, Cryptocoryne, and others. These can, of course, survive the transition between aquatic and "terrestrial" environments.

How long does the "dry season" have to last?

Well, if you want to mimic one of these habitats in the most realistic manner possible, follow the exact wet and dry seasons as you'd encounter in the locale you're inspired by. Alternatively, I'd at least go 2 months "dry" to encourage a nice growth of grasses and plants prior to inundation.

And of course, you cans do this over and over again! If you're trying to keep fishes like annual killifishes, the "dry season" could be used on the incubation period of their eggs.

When you flood the tank, doesn't  it make a cloudy mess? Does the water quality decline rapidly? 

Sure, when you add water to what is essentially a terrestrial "planter box", you're going to get cloudiness, from the sediments and other materials present in the substrate. You will have clumps of grasses or other botanical materials likely floating around for a while.

Surprisingly, in my experience, the water quality stays remarkably good for aquatic life. Now, I'm not saying that it's all pristine and crystal clear; however, if you let things settle out a bit before adding fishes, the water clears up and a surprising amount of life (various microorganisms like Paramecium, bacteria, etc.) emerges.

Curiously, I personally have NOT recorded ammonia or nitrite spikes following the inundation. That being said, you can and should test your water before adding fishes. You can also dose bacterial inoculants, like our own "Culture" or others, into the water to help. The Purple Non-Sulphur bacteria in "Culture" are extremophiles, particularly well adapted to the dynamics of the wet/dry environment.

Should I use a filter in the "wet season?"

You certainly can. I've gone both ways, using a small internal filter or sponge filter  in some instances. I've also played with simply using an air stone. Most of the time, I don't use any filtration. I just conduct partial water exchanges like I would with any other tank- although I take care not to disturb the substrate too much if I can. When I scaled up my "Urban Igapo" experiments to larger tanks (greater than 10 gallons), Il incorporated a filters with no issues. 

A lot of what we do is simply letting Nature "take Her course." 

Ceding a lot of the control to Nature is hard for some to quantify as a "technique" or "method", so I get it. At various phases in the process, our "best practice" might be to simply observe...

And with plant growth slowing down, or even going completely dormant while submerged, the utilization of nutrients via their growth diminishes, and aquatic life forms (biofilms, algae, aquatic plants, and various bacteria, microorganisms, and microcrustaceans) take over. There is obviously an initial "lag time" when this transitional phase occurs- a time when there is the greatest opportunity for one life form or another (algae, bacterial biofilms, etc.) to become the dominant "player" in the microcosm.

It's exactly what happens in Nature during this period, right?

And there are parallels in the management of aquariums.

In our aquarium practice, it's the time when you think about the impact of technique-such as water exchanges, addition of aquatic plants, adding fishes, reducing light intensity and photoperiod, etc. and (again) observation to keep things in balance- at least as much as possible. You'll question yourself...and wonder if you should intervene- and how..

It's about a number of measured moves, any of which could have significant impact- even "take over" the system- if allowed to do so. This is part of the reason why we don't currently recommend playing with the Urban Igapo idea on a large-tank scale just yet. (that, and the fact that we're not going to be geared up to produce thousands of pounds of the various substrates just yet! 😆)

Until you make those mental shifts to accept all of this stuff in one of these small tanks, the idea of replicating this in 40-50, or 100 gallons is something that you may want to hold off on for just a bit.

Or not.

I mean, if you understand and accept the processes, functions, and aesthetics of this stuff, maybe you wouldwant to "go big" on your first attempt. However, I think you need to try it on a "nano scale" first, to really "acclimate" to the idea.

The idea of accepting Nature as it is makes you extremely humble, because there is a realization at some point that you're more of an "interested observer" than an "active participant." It's a dance. One which we may only have so much control- or even understanding of! That's part of the charm, IMHO.

These habitats are a remarkable "mix" of terrestrial and aquatic elements, processes, and cycles. There is a lot going on. It's not just, "Okay, the water is here- now it's a stream!"

Nope. There is a lot of stuff to consider.

In fact, one of the arguments one could make about these "Urban Igapo" systems is that you may not want to aggressively intervene during the transition, because there is so much going on! Rather, you may simply want toobserve and study the processes and results which occur during this phase. Personally, I've noticed that the "wet season" changes in my UI tanks generally happen slowly, but you will definitely notice them as they occur. 

After you've run through two or three complete "seasonal transition cycles" in your "Urban Igapo", you'll either hate the shit out of the idea- or you'll fall completely in love with it, and want to do more and more work in this alluring little sub-sector of the botanical-style aquarium world.

The opportunity to learn more about the unique nuances which occur during the transition from a terrestrial to an aquatic habitat is irresistible to me. Of course, I'm willing to accept all of the stuff with a very open mind. Typically, it results in a fascinating, utterly beautiful, and surprisingly realistic representation of what happens in Nature.

It's also entirely possible to have your "Urban Igapo" turn into an "Urban Algae Farm" if things get out of balance. Yet, it can "recover" from this. Again, even the fact that a system is "out of balance" doesn't mean that it's a failure. After all, the algae is thriving, right? That's a success. Life forms have adapted. A cause to celebrate.

It happens in Nature, too!

So, that's a brief rundown on the dynamics and challenges of the "Urban Igapo" concept. It will be exciting to see how each of us evolves the idea further!

Stay creative. Stay thoughtful. Stay bold. Stay curious...

And Stay Wet.

 

Scott Fellman

Tannin Aquatics  

What's the big deal about substrates?

Of all the fun topics in botanical-style aquarium keeping, few hold my interest as much as substrates.

I imagine the substrate as this magical place which fuels all sorts of processes within our aquariums, and that Nature tends to it in the most effective and judicious manner. 

Yeah, I'm a bit of a "substrate romantic", I suppose.😆

Particularly in transitional habitats, like flooded forests, etc. the composition and characteristics of the substrate plays a huge role in the ecology of the aquatic habitat. The presence of a lot of soils, clays, and sediments in these substrates, as opposed to just sand, creates a habitat which provides a lot of opportunity for organisms to thrive.

The substrates are not just "the bottom." 

They are diverse harbors of life, ranging from fungal and biofilm mats, to algae, to epiphytic plants. Decomposing leaves, seed pods, and tree branches compose the substrate for a complex web of life which helps the fishes we're so fascinated by to flourish. And, if you look at them objectively and carefully, they are beautiful.

Detritus ("Mulm") located in the sediments is the major source of energy and/or nutrients for many of these dynamic aquatic habitats. The bacteria which perform all the important chemical reactions, such as converting ammonia to nitrite, nitrates to nitrogen, releasing bound-up nutrients, neutralizing hydrogen sulfide, etc. will obtain  essential nutrients from the detritus (this is what autotrophic bacteria that metabolize ammonia/ammonium or hydrogen sulfide for energy do).

These bacteria may also "harvest" those nutrients, as well as metabolize (aerobically or anaerobically) the organic compounds present in the detritus for energy, just like heterotrophs do.

The processing of nutrients in the aquarium is a fascinating one; a real "partnership" between a wide variety of aquatic organisms.

Yes, there is a lot of amazing biological function occurring in these layers. And of course, fostering this dynamic in the aquarium is one of the things we love the most. It's all part of our vision for the modern, botanical-style aquarium.

Now, hobbyists have played with deep sand beds and mixes of various materials in aquariums for many years, and knowledgable proponents of natural aquarium management, such as Diane Walstad, have discussed the merits of such features in far more detail, and with a competency that I could only dream of! That being said, I think the time has never been better to experiment with this stuff!

Again, we're talking about utilizing a wider variety of materials than just sand, so the dynamics are quite different, offering unique functions, processes, and potential benefits.

I've been thinking through further refinements of the "deep botanical bed"/sand substrate relationship. I've been spending a lot of time over the years researching natural aquatic systems and contemplating how we can translate some of this stuff into our closed system aquaria.

Before we talk about the actual substrate materials again, let's think about the processes that we would like to foster in a substrate, and the potential negatives that may be of concern to those of us who play with botanicals in our substrate configurations

 One of the things that many hobbyists ponder when we contemplate creating deep, botanical-heavy substrates, consisting of leaves, sand, and other botanical materials is the buildup of hydrogen sulfide, CO2, and other undesirable compounds within the substrate.

Well, it does make sense that if you have a large amount of decomposing material in an aquarium, that some of these compounds are going to accumulate in heavily-"active" substrates. Now, the big "bogeyman" that we all seem to zero in on in our "sum of all fears" scenarios is hydrogen sulfide, which results from bacterial breakdown of organic matter in the total absence of oxygen.

Let's think about this for just a second.

In a botanical bed with materials placed on the substrate, or loosely mixed into the top layers, will it all "pack down" enough to the point where there is a complete lack of oxygen and we develop a significant amount of this reviled compound in our tanks? I think that we're more likely to see some oxygen in this layer of materials, and I can't help but speculate- and yeah, it IS just speculation- that actual de-nitirifcation (nitrate reduction), which lowers nitrates while producing free nitrogen, might actually be able to occur in a "deep botanical" bed.

And it's certainly possible to have denitrification without dangerous hydrogen sulfide levels. As long as even very small amounts of oxygen and nitrates can penetrate into the substrate, this will not become an issue for most systems. I have yet to see a botanical-style aquarium where the material has become so "compacted" as to appear to have no circulation whatsoever within the botanical layer.

Now, sure, I'm not a scientist, and I base this on close visual inspection of numerous aquariums, and the basic chemical tests I've run on my systems under a variety of circumstances. As one who has made it a point to keep my botanical-style aquariums in operation for very extended time frames, I think this is significant. The "bad" side effects we're talking about should manifest over these longer time frames...and they just haven't.

We need to look at substrates literally as an aquatic organism. And, like aggregations of organisms, they may be diverse, both morphologically and ecologically. They're a dynamic, functional part of the miniature ecosystems we create in our aquariums. We've used the "basic" stuff for a generation. It's time to open up our minds to a few new ideas. To rethink substrate. To reconsider why we incorporate substrate, and what we use.

What kinds of materials can we employ to create more "functional" substrates (which just happen to look cool, too?). What kinds of functions and benefits can we hope to recreate in the confines of our aquariums?

 

First off, think beyond just sands...or anything resembling "conventional" aquarium substrate. Think about what goes on in the benthic (bottom) regions in the natural habitats we love, and what benefits or support the materials which aggregate there provide for the organisms within the ecosystem.

Understand that the substrate is a dynamic, extremely important part of the aquarium, too. And what we construct our substrate with, and how we manage it, is of profound importance to our fishes!

Fostering fungal growth, as well as other microorganisms and small crustaceans, should be a huge component of the "why" we do this. These organisms, as we've discussed repeatedly, form a part of the "food chain" within our captive ecosystems, and offer huge benefits to the aquarium not only as potential supplemental nutrition for fishes, but as a means to process and export nutrients from within the botanical-style aquarium.

 

So, yeah, in summary- the substrate plays a huge role in the function of a botanical-style aquarium. We can create a "facility" with substrate materials which provides not only unique aesthetics- it provides priceless benefits: Production of supplemental nutrition for our fishes, and nutrient processing via a self-generating population of creatures that compliment, indeed, create the biodiversity in our systems on a more-or-less continuous basis.

True "functional aesthetics!"

A combination of finely crushed leaves, bits of botanicals, small twigs, etc. can form the basis for a more "biologically active" and even productive substrate. As these materials break down, they are colonized by fungi and biofilms, and impart  tannins, lignin, and other sources of carbon into the water to fuel a variety of microbial growth. 

As you might have gathered by now, we are an advocate of some rather "unconventional" substrate materials, particularly a classification what we call "Sedimented Substrates." 

Yeah, that'd be ours. NatureBase "Igapo", "Varzea", and the upcoming "Mangal", "Floresta" and "Selagor", are examples of substrates which have a lot of sediments and clays in their formulation. These substrates realistically replicate the composition, function, and look of soils which are found in many tropical aquatic habitats.

In fact, most of our NatureBase substrates have a significant percentage of clays and sediments in their formulations. These materials have typically been something that aquarists have avoided, because they will cloud the water for a while, and often impart a bit of color. Like, that's a problem? We also have some botanical components in a few of our substrates, because they are intended to be "terrestrial" substrates for a while before being flooded...and when this stuff is first wetted, some of it will float. And that means that you're going to have to net it out, or let your filter take it out.

You simply won't have that "issue" with your typical bag of aquarium sand!

You can mix them with any of the above-mentioned commercially-available sands, or use them alone. You can gradually add water (as in our "Urban Igapo" concept), or simply fill your tank form day one. Expect significant cloudiness for several days as the materials settle out, though. Don't rinse these substrates...just put them to work right away.

Now, although you can (and should) play with these substrates "wet" from the start, I'd be remiss if I didn't remind you again that the igapo and varzea substrates were initially intended to be "terrestrial" for a period of time, to get the grasses and plants going, and then inundated.  

 

So, yeah, you'll have to make a mental shift to appreciate a different look and function. And many hobbyists simply can't handle that. We've been up front with this stuff since these products were released, to ward off the, "I added NatureBase to my tank and it looks like a cloudy mess! This stuff is SHIT!" type of emails that inevitably come when people don't read up first before they purchase the stuff.  

And the warning and mental shift indoctrinations have worked. No one has freaked out.

Instead, we're hearing how incredibly natural these aquariums look, and how the biological diversity and stability of these tanks are.

What goes on in an aquarium with sediments, botanicals- or leaves, in this instance as the total  "substrate" or "hardscape", as the case may be, is that they become the basis for biological activity in the tank. As we have discussed a million times here, as botanicals break down, they recruit bacteria, fungi, and other organisms on their surfaces.

That's the "big deal" about substrates.

Mix it up. Play with sediments, crushed leaves, broken bits of botanicals..All sorts of natural "stuff" which would previously have been considered "dirty" and "bad for long term maintenance" in almost anyone's book. Look at the advantages that can be realized, instead of the potential risks involved in experimenting.

Open your mind up to accept the look and function- and the "aesthetic challenges" of using non-traditional materials in your substrates. 

Stay creative. Stay excited. Stay bold. Stay studious...

And Stay Wet.

 

Scott Fellman

Tannin Aquatics