The Tint

Your fishes call it "food..."

If you've followed us for any length of time, you're well aware that we are not just pushing you to play with natural, botanical-method aquariums only for the pretty aesthetics.

I mean, yeah, they look awesome, but there is so much more to it than that. We are unapologetically obsessed with the function of these aquariums and the wild habitats which they attempt to represent!

And one of the most important functions of many botanically-influenced wild habitats is the support of what ecologists call food webs-a system of interlocking and interdependent food chains...in other words, "what eats what" in the aquatic ecosystem!

It's a fascinating field of study that plays beautifully into what we do in our botanical method aquariums.

As we've discussed before, the leaf litter zones in tropical waters are home to a remarkable diversity of life, ranging from microbial to fungal, as well as crustaceans and insects...oh, and fishes, too!  These life forms are the basis of complex and dynamic food webs, which are one key to the ecological "productivity" of these habitats.

By researching, developing, and managing our own botanically-influenced aquaria, particularly those with leaf litter beds, we may be on the cusp of finding new ways to create "nurseries" for the rearing of many fishes!

At least upon superficial examination, our aquarium leaf litter/botanical beds seem to function much like their wild counterparts, creating an extremely rich "microhabitat" within our aquariums. And initial reports form those of you who breed and rear fishes in your intentionally "botanically-stocked" aquariums are that you're seeing great color, more regularity in spawns, and higher survival rates from some species.

I don't believe that this is mere coincidence.

We're just beginning here, and the future is wild open for huge hobbyist-level contributions that can lead to some serious breakthroughs in understanding how food webs develop in aquariums! 

Maybe we will finally overcome generations of fear over detritus and fungi and biofilms- the life-forms and "by-products" which literally "power" the aquatic ecosystems we strive to duplicate in our aquariums.

There is something tantalizing to me about the idea of our fishes being able to supplement what we feed them by foraging in the aquarium. To some extent, virtually every aquairum has some microorganisms, algae, etc. which fishes can "snack on" in between our feedings. Yet, botanical-method aquariums, with their abundance of decomposing leaves and the ecology which they foster, take this to a whole different level.

I'm particularly fascinated with the idea of the fry of our fishes being able to sustain themselves or supplement their diets substantially, with what is produced inside the little habitat we've created in our tanks! A botanical method aquarium is, I believe, an ideal "nursery" for many species of fishes to begin their lives, and the experience of many of my fish-breeding friends who have played with this idea successfully helps to prove my thesis.

 

Let's consider some of the types of food sources that our fishes might utilize in the wild habitats that we try so hard to replicate in our aquariums, and perhaps develop a greater appreciation for them when they appear in our tanks. Perhaps we will even attempt to foster and utilize them to our fishes' benefits in unique ways?

One of the important food resources in natural aquatic systems are what are known as macrophytes- aquatic plants- which grow in and around the water, emerged, submerged, floating, etc. Not only do macrophytes contribute to the physical structure and spatial organization of the water bodies they inhabit, they are primary contributors to the overall biological stability of the habitat, conditioning the physical parameters of the water. Of course, anyone who keeps a planted aquarium could attest to that, right? 

 

One of the interesting things about macrophytes is that, although there are a lot of fishes which feed directly upon them, in this context, the plants themselves are perhaps most valuable as a microhabitat for algae, zooplankton, and other organisms which fishes feed on. Small aquatic crustaceans seek out the shelter of plants for both the food resources they provide (i.e.; zooplankton, diatoms) and for protection from predators (yeah, the fishes!).

I have personally set up a couple of systems recently to play with this idea- botanical-influenced planted aquariums, and have experimented with going extended periods of time without feeding my fishes who lived in these tanks- and they have remained as fat and happy as when they were added to the tanks…

Something is there- literally!  

Perhaps most interesting to us botanical-method aquarium people are epiphytes. These are organisms which grow on the surface of plants or other substrates and derive their nutrients from the surrounding environment. They are important in the nutrient cycling and uptake in both nature and the aquarium, adding to the biodiversity, and serving as an important food source for many species of fishes.

In the case of our aquatic habitats, like streams, ponds, and inundated forests, epiphytes are abundant, and many fishes will spend large amounts of time foraging the biocover on tree trunks, branches, leaves, and other botanical materials. Although most animals use leaves and tree branches for shelter and not directly as a food item, grazing on this epiphytic growth is very important.

Some organisms, such as nematodes and chironomids ("Bloodworms!") will dig into the leaf structures and feed on the tissues themselves, as well as the fungi and bacteria found in and among them. These organisms, in turn, become part of the diet for many fishes.

And the resulting detritus produced by the "processed" and decomposing pant matter is considered by many aquatic ecologists to be an extremely significant food source for many fishes, especially in areas such as Amazonia and Southeast Asia, where the detritus is considered an essential component of the food webs in these habitats. 

And of course, if you observe the behavior of many of your fishes in the aquarium, such as characins, cyprinids, Loricarids, and others, you'll see that in between feedings, they'll spend an awful lot of time picking at "stuff" on the bottom of the tank. In a botanical style aquarium, this is a pretty common occurrence, and I believe an important benefit of this type of system. 

I am of the opinion that a botanical-method aquarium, complete with its decomposing leaves and seed pods, can serve as a sort of "buffet" for many fishes- even those who's primary food sources are known to be things like insects and worms and such. Detritus and the organisms within it can provide an excellent supplemental food source for our fishes!

Just like in Nature. 

 

It's well known by scientists that in many habitats, like inundated forest floors, etc., fishes will adjust their feeding strategies to utilize the available food sources at different times of the year, such as the "dry season", etc. And it's also known that many fish fry feed actively on bacteria and fungi in these habitats...so I suggest once again that a botanical method aquarium could be an excellent sort of "nursery" for many fish species! 

 

You'll often hear the term "periphyton" mentioned in a similar context, and I think that, for our purposes, we can essentially consider it in the same manner as we do "epiphytic matter." Periphyton is essentially a "catch all" term for a mixture of cyanobacteria, algae, various microbes, and of course- detritus, which is found attached or in extremely close proximity to various submerged surfaces. Again, fishes will graze on this stuff constantly.

 

And then, of course, there's the “allochthonous input” that we’ve talked about so much: Foods from the surrounding environment, such as flowers, fruits, terrestrial insects, etc. These are extremely important foods for many fish species that live in these habitats. We mimic this process when we feed our fishes prepared foods, as stuff literally "rains from the sky!" Now, I think that what we feed to our fishes directly in this fashion is equally as important as how it's fed.

I'd like to see much more experimentation with foods like live ants, fruit flies, and other winged insects. Of course, I can hear the protests already: "Not in MY house, Fellman!" I get it. I mean, who wants a plague of winged insects getting loose in their suburban home because of some aquarium feeding experiment gone awry, right?

That likely wouldn't go over well with just about any significant other in the "non-aquarium" world, right?

That being said, I would encourage some experimentation with ants and the already fairly common wingless fruit flies. Sure, you can just catch some ants outside and drop them into your tank...or you could culture them...Remember those "Ant Farms" that some of us had when we were kids?

Can you imagine one day recommending an "Ant Farm" as a piece of essential aquarium food culturing equipment? It's at least as wacky as culturing peanut beetle larvae or microworms, and not nearly as messy!

Why not, right? 😆

And of course, easier yet- we can simply foster the growth of potential food sources that don't fly or crawl around- they just arise when botanicals and wood and stuff meet water...We just need to not wipe them out as soon as they appear! Damn, using the collection and feeding of winged insects as an opposite example sure makes fungal growths and biofilms more palatable, right?

As many of you may know, I've often been sort of amused by the panic that many non-botanical-style-aquarium-loving hobbyists express when a new piece of driftwood is submerged in the aquarium, often resulting in an accumulation of fungi and biofilm.

I realize this stuff can look pretty shitty to many of you, particularly when you're trying to set up a super-cool, "sterile high-concept" aquascaped tank.

That being said, I think we need to let ourselves embrace this stuff and celebrate it for what it is: Life. Sustenance. Diversity. Foraging.

I think that those of us who maintain botanical method aquariums have made the "mental shift" to understand, accept, and even celebrate the appearance of this stuff.

We learn to appreciate it by looking to Nature.

Natural habitats are absolutely filled with this stuff...in every nook and cranny. On every rock, branch, seed pod, and leaf. It's like the whole game here- an explosion of life-giving materials, free for the taking...

A priceless natural resource.

It's why, a long time ago, I learned to not be put off by the mere appearance of these life forms when they showed up in my early botanical method aquariums. They are literally the drivers of underwater ecology- a priceless resource which Nature happily deposits into our aquariums. 

A true gift from Nature. 

Yet, for a century or so in the hobby, our first instinct is to reach for the algae scraper or siphon hose, and lament our misfortune with our friends.

It need not be this way. Its appearance in our tanks is a blessing. 

Really.

You call it "mess." I call it a blessing.  Your fishes call it “food."

Another "mental shift", I suppose...one which many of you have already made, no doubt. Or, I hope you have..or can.

The ability to appreciate this stuff- to move beyond the fear, loathing, and disdain which many hobbyists have for it-is to truly grow as a hobbyist. In fact, the oft-quoted, absurdly mis-interpreted and applied (to the point where it's almost a mockery) statement by none other than the late Akashi Amano that, "To know Mother Nature is to love her smallest creations..." sums this up perfectly. 

Yeah, he got it. 

You can, too. 

Now look, I'm not saying that your tank has to be packed with biofilms, fungal growth, decomposing leaves, and detritus in order to provide all of these benefits to your fishes. However, I am suggesting that, as hobbyists, we should to allow some amount of this material to accumulate in our tanks.

Remember, the presence of these materials does not signify some "problem" with your aquarium, as is so easy to conclude. 

Rather, their presence indicates that your aquarium is functioning very much like a natural aquatic ecosystem. That it's doing what Nature has done for eons. To disrupt the process by aggressively siphoning out every gram of detritus, scraping off every bit of fungal growth or biofilm actually inhibits or even completely disrupts processes which can benefit your tank in manifold ways.

Not only do fungal growths and biofilms serve as a supplemental food resource for our fishes, they help "filter" the water by processing nutrients. And a large part of their "fuel" is the leaf litter, seed pods, wood, and the detritus which occurs as a result of their decomposition. 

 Yeah, we talk about this a lot around here, I know. 

However, it's such an important part of our philosophy and methodology that it cannot be stated often enough. 

And the sooner we embrace this stuff, the sooner we begin to realize the lasting benefits that it can bring to our aquariums!

Stay confident. Stay bold. Stay curious. Stay diligent. Stay studious...

And Stay Wet.

 

Scott Fellman

Tannin Aquatics 

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 

 

Anything goes? Well, sort of...

The garden suggests there might be a place where we can meet Nature halfway."-Michael Pollan

It's long been suggested that an aquarium is sort of like a garden, right? And, to a certain extent it is. Of course, we can also allow our tanks to evolve on a more-or-less "random" path than the word "garden" implies...

Perhaps one of the most liberating things about our botanical-method aquariums is that there is no set "style" that you have to follow to "arrange" botanical materials in your tank. 

When you look at those amazing pictures of the natural habitats we love so much, you're literally bombarded with the "imperfection" and apparent randomness that is Nature. Yet, in all of the "clutter" of an igarape flooded forest, for example, there is a quiet elegance to it. There is a sense that everything is there for a reason- and not simply because it looks good. It IS perfect. Can't we bring this sense to our aquariums?

I think we can...simply by meeting Nature halfway.

To a certain extent, it's "anything goes" in terms of adding materials to represent the wild habitats. I mean, when you think about flooded forest floors and rainforest streams, you're talking about an aggregation of material from the forest that has accumulated via wind, rain, and current. The influences on the "design" are things like how something arrives into the water, and how it gets distributed by water movement. 

Nature offers no "style guide." 

Rather, she offers clues, based on her processes.

I mean, sure, you could and should certainly use some aesthetic thought in the concept, but when you're trying to recreate what in Nature is a more-or-less random thing, you probably don't want to dwell too much on the concept! You don't want to over-think "random" too much, right? Rather, put your effort into selecting suitable materials with which to do the job.

For a bit more context, just think for just a second, about the stems and branches that we love so much in our aquascaping. Those of us who obsessively study images of the wild tropical habitats we love so much can't help but note that many of the bodies of water which we model our aquariums after are filled with tree branches and stems.

Since many of these habitats are rather ephemeral in nature, they are only filled up with water part of the year. The remainder of the time, they're essentially dry forest floors.

And what accumulates on dry forest floors?

Branches, stems, leaves, 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 how 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 once submerged. There are numerous random factors involved. 

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 literally tossing materials in and walking away! Now, I know this is actually aquascaping heresy- Not one serious 'scaper would ever do that...right?

On the other hand, I'm not so sure why they wouldn't! 

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 shit that hardcore 'scapers will hit you over the head with...

But Nature doesn't give a fuck about some competition'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."

Natural looks...well, like what you'd see in Nature.

It's pretty hardcore stuff.

And it's all part of the reason that I spend so damn much time pleading with you- my fellow fish geeks- to study, admire, and ultimately replicate natural aquatic habitats as much as you do the big aquascaping contest winners' works. In fact, if every hobbyist spent just a little time studying some of these unique natural habitats and using them as the basis of their work, I think the hobby would be radically different.

When hobbyists interpret what they see in wild aquatic habitats stats more literally, the results are almost always stunning. And contest judges are starting to take notice...

I think that there would also be hobby success on a different level with a variety of fishes that are perhaps considered elusive and challenging to keep. Success based on providing them with the conditions which they evolved to live in over the millennia, not a "forced fit" its what works for us humans.

More awareness of both the function and the aesthetics of fascinating ecological niches, such as the aforementioned flooded forests, would drive the acceptance and appreciation of Nature as it is- not as we like to "edit" and "sanitize" it.

Taking this approach is actually a "stimulus" for creativity, perhaps in ways that many aquarists have not thought of. 

There are a lot of aquatic habitats in Nature which are filled with tangles of terrestrial plant roots, emergent vegetation, fallen branches, etc., which fill small bodies of water almost completely.

These types of habitats are unique; they attract a large populations of smaller fishes to the protection of their vast matrix of structures. Submerged fallen tree branches or roots of marginal terrestrial plants provide a large surface area upon which algae, biofilm, and fungal growth occurs. This, in turn, attracts higher life forms, like crustaceans and aquatic insects. Sort of the freshwater version of a reef, from a "functionality" standpoint, right?

Can't we replicate such aquatic features in the aquarium?

Of course we can!

This idea is a fantastic expression of "functional aesthetics." It's a "package" that is a bit different than the way we would normally present an aquarium. Because we as hobbyists hesitate to densely pack an aquarium like this, don't we?

Why do you think this is?

I think that we hesitate, because- quite frankly- having a large mass of tangled branches or roots and their associated leaves and detritus in the cozy confines of an aquarium tends to limit the number, size, and swimming area of fishes, right? Or, because its felt that, from an artistic design perspective, something doesn't "jibe" about it...

Sure, it does limit the amount of open space in an aquarium, which has some tradeoffs associated with it.

On the other hand, I think that there is something oddly compelling, intricate, and just beautiful about complex, spatially "full" aquatic features. Though seldom seen in aquarium work, there is a reason to replicate these systems. And when you take into account that these are actually very realistic, entirely functional representations of certain natural habitats and ecological niches, it becomes all the more interesting!

What can you expect when you execute something like this in the aquarium?

Well, for on thing, it WILL take up a fair amount of space within the tank. Of course. Depending upon the type of materials that you use (driftwood, roots. twigs, or branches), you will, of course, displace varying amounts of water.

Flow patterns within the aquarium will be affected, as will be the areas where leaves, detritus and other botanical materials settle out. You'll need to understand that the aquarium will not only appear different- it'll function differently as well. Yet, the results that you'll achieve- the more natural behaviors of your fishes, their less stressful existence- will provide benefits that you might not have even realized possible before. 

This is something which we simply cannot bring up often enough. It's transformational in our aquarium thinking. 

The "recruitment" of organisms (algae, biofilms, epiphytic plants, etc.) in, on, and among the matrix of wood/root structures we create, and the "integration" of the wood into other "soft components" of the aquascape- leaves and botanicals is something which occurs in Nature as well as in the aquairum.

This is an area that has been worked on by hobbyists rather infrequently over the years- mainly by biotope-lovers. However, embracing the "mental shifts" we've talked about so much here- allowing the growth of beneficial biocover, decomposition, tinted water, etc.- is, in our opinion, the "portal" to unlocking the many secrets of Nature in the aquarium.

The extraordinary amount of vibrance associated with the natural growth on wood underwater is an astounding revelation. However, our aesthetic sensibilities in the hobby have typically leaned towards a more "sterile", almost "antispetic" interpretation of Nature, eschewing algae, biofilm, etc.

However, a growing number of hobbyists worldwide have began to recognize the aesthetic and functional beauty of these natural occurances, and the realism and  I think that the intricate beauty of Nature is starting to eat away at the old "sterile aquascape" mindset just a bit!

And before you naysayers scoff and assert that the emerging "botanical method" aquarium is simply an "excuse for laziness", as one detractor communicated to me not too long ago, I encourage you once again to look at Nature and see what the world underwater really looks like. There is a reason for the diversity, apparent "randomness", and success of the life forms in these bodies of water.

What is it?

It's that these materials are being utilized- by an enormous community of organisms- for shelter, food, and reproduction. Seeing the "work" of these organisms, transforming pristine" wood and crisp leaves into softening, gradually decomposing material, is evidence of the processes of life.

When you accept that seed pods, leaves, and other botanical materials are somewhat ephemeral in nature, and begin to soften, change shape, accrue biofilms and even a patina of algae- the idea of "meeting Nature halfway" makes perfect sense, doesn't it? 

You're not stressing about the imperfections, the random patches of biofilm, the bits of leaves that might be present in the substrate. Sure, there may be a fine line between "sloppy" and "natural" (and for many, the idea of stuff breaking down in any fashion IS "sloppy")- but the idea of accepting this stuff as part of the overall closed ecosystem we've created is liberating.

Sure, we can't get every functional detail down- every component of a food web- every biochemical interaction...the specific materials found in a typical habitat- we interpret- but we can certainly go further, and continue to look at Nature as it is, and employ a sense of "acceptance"- and randomness-in our work. 

I'm not telling you to turn your back on the modern popular aquascaping scene; to disregard or dismiss the brilliant work being done by aquascapers around the world, or to develop a sense of superiority or snobbery, and conclude that everyone who loves this stuff is a sheep...

Noooooo.

Not at all.

I'm simply the guy who's passing along the gentle reminder from Nature that we have this great source of inspiration that really works! Rejoice in the fact that Nature offers an endless variety of beauty, abundance, and challenge- and that it's all there, free for us to interpret it as we like. Without aesthetic rules, rigid standards, and ratios. The only "rules" are those which govern the way Nature works with materials in an aquatic environment.

A botanical-method aquarium features, life, death, and everything in between.

It pulses with the cycle of life, beholden only to the rules of Nature, and perhaps, to us- the human caretakers who created it.

But mainly, to Nature.

The processes of life which occur within the microcosm we create are indifferent to our desires, our plans, or our aspirations for it. Sure, as humans, we can influence the processes which occur within the aquarium- but the ultimate outcome- the result of everything that we did and did not do- is based solely upon Nature's response.

In the botanical-style aquarium, we embrace the randomness and unusual aesthetic which submerged terrestrial materials impart to the aquatic environment. We often do our best to establish a sense of order, proportion, and design, but the reality is that Nature, in Her infinite wisdom borne of eons of existence, takes control.

It's a beautiful process. Seemingly random, yet decidedly orderly.

Think about that for a bit.

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

And Stay Wet.

 

Scott Fellman

Tannin Aquatics 

 

The "fungal filter?"

You saw the title.

What exactly am I talking about here? 

 

 

Today, I want to double back and talk a bit about our gooey friends, the fungi- for just a few minutes. Despite their off-putting appearance to some, they may be among the most beautiful, elegant, and useful organisms we encounter in the aquatic world.

Why do I have such devotion to organisms which most of us find truly revolting in appearance? 

Because they are among the most important and useful organisms which we can have in our botanical method aquariums. Think about how they arrive in aquatic ecosystems, what they consume, how they derive nutrition, and what they do for the overall ecosystem.

As everyone knows, when you put stuff in water, one of four things seems to happen:

1) Nothing.

2) It gets covered in a gooey slime of fungal growth, and "biofilm."

3) It starts to break down and decompose.

4) Both 2 and 3

Now, it's pretty much a "given" that any botanicals or leaves that you drop into your aquarium will, over time, break down. Wood, too. And typically, before they break down, they'll "recruit" (a fancy word for "acquire') a coating of some rather unsightly-looking growth. Well, "unsightly" to those who have not been initiated into our little world of decomposition, fungal growth, biofilms, tinted water, etc., and maintain that an aquarium by definition is a pristine-looking place without a speck of anything deemed "aesthetically unattractive" by the masses! 

So, with that little explanatory passage out of the way, let's take a closer look at fungi-the stuff that you'll see covering the leaves, botanicals, and wood that you place into your aquarium, and why you actually WANT the stuff there in the first place.

The fungi known as aquatic hyphomycetes produce enzymes which break down botanical materials in water. Essentially, they are primary influencers of leaf maceration. They're remarkably efficient at what they do, too. In as little as 3 weeks, as much as 15% of the decomposing leaf biomass in many aquatic habitats is "processed" by fungi, according to one study I found!

Aquatic hyphomycetes play a key role in the decomposition of plant litter of terrestrial origin- an ecological process in rain forest streams that allows for the transfer of energy and nutrients to higher tropic levels. 

This is what ecologists call "nutrient cycling", folks.

These fungi colonize leaf litter and twigs and such soon after they're immersed in water. The fungi mineralize organic carbon and nutrients and convert coarse particulate matter into fine particulate organic matter. They also increase leaf litter palatability to shredders, which helps facilitate physical fragmentation.

Fungi tend to colonize wood and botanical materials, because they offer them a lot of surface area to thrive and live out their life cycle. And cellulose, hemicellulose, and lignin- the major components of wood and botanical materials- are degraded by fungi, which posses enzymes that can digest and assimilate these materials and their associated organics!

Fungi are regarded by biologists to be the dominant organisms associated with decaying leaves in streams, so this gives you some idea as to why we see them in our aquariums, right?

In aquarium work, we see fungal colonization on wood and leaves all the time. Most hobbyists will look on in sheer horror if they saw the same extensive amount of fungal growth on their carefully selected, artistically arranged wood pieces as they would in virtually any aquatic habitat in Nature!

Yet, it's one of the most common, elegant, and beneficial processes that occurs in natural aquatic habitats!

It's everywhere.

Of course, fungal colonization of wood and botanicals is but one stage of a long process, which occurs in Nature and our aquariums. And, as hobbyists, once we see those first signs of this stuff, the majority of us tend to reach for the algae scraper or brush and remove as much of it as possible- immediately! And sure, this might provide some "aesthetic relief" for some period of time- but it comes right back...because these materials will provide a continuous source of food and colonization sites for fungal growths for some time!

I know that the idea of "circumventing" this stuff is appealing to many, but the reality is that you're actually interrupting an essential, ecologically beneficial natural process. And, as we know, Nature abhors a vacuum, and new growths will return to fill the void, thus prolonging the process.

Remember, your aquairum is not a pice of kinetic art. It's a miniature, closed aquatic ecosystem. Processes which occur in Nature play out daily in your tank.

Yeah, I admit, decades ago, I freaked out about seeing fungal growths in my tanks, too. I'd get a bit scared, wondering if something was wrong, and why no one else's aquariums ever seemed to look like mine. I used to think something was really wrong!

To reassure myself, I would stare for hours at underwater photos taken in the Amazon region, showing decaying leaves, biofilms,and fungi all over the leaf litter. I'd read the studies by researchers like Henderson and Walker, detailing the dynamics of wild leaf litter zones and how productive and unique they were.

I remember telling myself that what I was seeing in my tanks was remarkably similar to what I saw in images and videos of wild aquatic habitats that I wanted to replicate. They seem to look- and even function- so similarly.

I'd pour over my water quality tests, confirming for myself that everything was okay. It always was. And of course I would watch my fishes for any signs of distress...

I never saw them.

Truth be known, I knew that there wouldn't be any issues, because I created my aquariums with a solid embrace of basic aquatic biology; an understanding that an aquarium is not some sort of underwater art installation, but rather, a living, breathing microcosm of organisms which work together to create a biome..and that the appearance of the aquarium only tells a small part of the story.

 

And another big concept for you to wrap your head around:

Your aquarium- or more specificlally- the colonized botanical materials which comprise the botanical-method aquarium "infrastructure" acts as a biological "filter system."

In other words, the botanical materials present in our systems provide enormous surface area upon which beneficial bacterial biofilms and fungal growths can colonize. These life forms, like fungi, utilize the organic compounds present in the water as a nutritional source, thus creating a "nutrient assimilation process."

Understanding and embracing this has changed everything about how I look at aquarium management and the creation of functional closed aquatic ecosystems. 

It's really put the word "natural" back into the aquarium keeping parlance for me. The idea of creating a multi-tiered ecosystem, which provides a lot of the requirements needed to operate successfully with just a few basic maintenance practices, the passage of time, a lot of patience, and careful observation.

It means adopting a different outlook, accepting a different, yet very beautiful aesthetic. It's about listening to Nature instead of the "influencer" on YouTube with the flashy, gadget-driven tank and nothing substantive to back up his vapid narrative. It means educating yourself a bit. It's not always fun at first for some, and it initially seems like you're somehow doing things wrong.

But you're not. And Mother Nature won't let you down if you don't lose faith in Her.

And yeah- it's about faith. Faith in Mother Nature, who's been doing this stuff for eons. She's got this. She'll hook you up...If you allow Her. If you have faith in Her processes.

Have faith.

Stay bold. Stay thoughtful. Stay curious. Stay patient...

And Stay Wet.

 

Scott Fellman

Tannin Aquatics 

 

"Aquarium practice rooted in neither culture nor tradition..."

I've been asked a lot lately to comment on our philosophical position here at Tannin; a sort of rundown of what makes us tick, and how we arrived at our overriding approach and mindset. And, looking back on our past 7 years of operation, it's interesting for me, too.

If you haven't noticed, we tend to take a different view of the aquarium hobby around. here. Not that we don't respect, value, or love all of the traditions of the hobby as it exists- we do. However, in practice, we look at things from a slightly different point of view; one which puts Nature in charge of a lot of things.

We look at it as if we have a responsibility to step out of the way a bit; to cede a little control to Nature...To set the stage and to let natural processes play out in our tanks with limited, if any intervention on our part.

To create more naturally-functioning aquatic, authentic-looking displays for our fishes. To understand and acknowledge that our fishes- and their very existence- is influenced by the habitats in which they have evolved. 

Although a high percentage of the wild aquatic habitats that we love some much happen to consist of earthy, brown water, with decomposing leaves, twigs, and seed pods, we are inspired by, and play with all sorts of habitats, ranging from crystal clear karmic rivers, to brackish water estuaries, to the Rift Lakes of Africa. It's all about finding inspiration from a variety of natural aquatic habitats, and replicating their function, to the best of our ability, in aquariums.

It's not just "lip service", either. When you look at some of the aquariums we've advocated for, created and managed, that becomes fairly obvious!

We advocate some rather "unconventional" stuff.

But is it really THAT unconventional?

All we're doing is focusing on the more "natural" part of Nature, if that makes sense. We're not overstating our skill in what we do, nor basting our work with vapid rhetoric. We're just doing stuff. A bit differently. Questioning some long-held beliefs. Trying to recreate natural function in the aquarium- perhaps, a bit less "traditionally" than has previously been done in the hobby.

And it all starts with our view of Nature, and our place within it as aquarists. Hobbyists love to expound on ideas about Nature, and how what they do is an "expression of Nature", in a reverent, almost religious way. Cool, I guess, but sometimes, I find it a bit silly. I mean, every aquarium is an expression of Nature to a certain extent.

Those prosaic, often pretentious, haiku-like statements that we see posted by aquarists online about "...standing before Nature" and stuff like that sound really cool, but what the hell do they mean? And, if the aquarium that you're executing when spouting this stuff is as relevant to a wild natural aquatic habitat as a vase full of cut flowers is to a mountain meadow, how do you reconcile that kind of lofty rhetoric?

It just rings hollow when you think about it.

Unfortunately, in our social-media-soundbite iteration of the hobby, that kind of "word salad" makes a great Instagram Reel, or whatever. The headline is rad. But it "dumbs stuff down" and objectively tends to fall flat when you really look for some real meaning behind it.

In a very real way, the creation of an aquarium is a search for meaning.

The relationship between Nature and our aquariums makes a lot more sense when you look at, and study the wild aquatic habitats of the world, and and attempt to replicate their function as accurately as possible. The appearance, which we as humans hold so important, seems to follow the function. We either like it, or we don't.

That's pretty straightforward...

Of course, not everyone likes the appearance of aquariums created and executed in this manner. This makes sense. Nature doesnt create aquatic habitats for our viewing pleasure. Not all of Her creations square with our hobby definition of "beautiful."

Nature doesn't care.

Our approach understands this, and rather than trying to warp Nature into something that looks "right" to us, we advocate making mental shifts to see the beauty in what Nature does, and to embrace this stuff when it happens in our aquariums.

It's not about trying to win some contest, receive accolades from the Instagram crowd, or trying to meet some rigid standards set out for competition "biotope aquariums." You won't garner a million adoring YouTube fans by presenting aquariums filled with decomposing leaves and brown water. You won't have contest judges throwing roses at your feet. And you won't be creating aquariums that look like what you're used to seeing pretty much everywhere.

Rather, our philosophy is about looking at Nature as it is, and accepting all of it. Humbly accepting, of course, that we can't perfectly replicate every aspect of Nature and her function to the "nth degree." Instead, it's about learning what we can from the wild aquatic habitats of the world and trying to bring their function into our home aquariums to the greatest extent possible.

That means embracing stuff like sediment, turbidity, tinted water, fungal threads, biofilms, decay, and detritus...the results of natural processes which occur when terrestrial materials are immersed in water. 

Stuff which, quite frankly, freaks most hobbyists out. Full stop.

 

To you, it also means mentally shifting to not freak out about the appearance of these things in our aquaruims.

To not seek ways to eradicate them; rather, to contemplate what makes them form, and what role they play in the overall aquatic ecosystem that we have created, And indeed, to rejoice in the fact that these same things happen in the wild aquatic habitats we strive so hard to attempt to replicate in our tanks.

These principles, and the mental shifts that we make to accept them, form the "transportive mechanism" of the botanical method aquarium. It challenges you. It tests you. It doesn't give a damn about what you think it should look like. It's about ceding some control to Nature- something not always comfortable to everyone.

It's an aquarium practice neither rooted in tradition nor hobby culture. Rather, it's based upon the whims and functions of Nature Herself.

Tradition...not included?

Well, yeah...for the most part. Because "aquarium tradition" typically eschews stuff like algal films, detritus, fungal growth, turbidity, etc. It's long been part of aquarium "culture" to control, limit, or eradicate these things..to stifle natural processes rather than allow them to play out in our tanks.

However, beautiful things can happen when you meld this understanding with your skills, talents, and a good attitude.

And loving this stuff; embracing it- doesn't mean you're somehow "cool" and are a "rebel" or a visionary or something. It doesn't mean that every single aquarium you do has to be a dark, turbid morass of decomposing leaves and jumbled sediments.

It just means that you have a slightly different philosophy, outlook, and acceptance of some stuff than the majority of aquarists do. Stuff that impacts the way you create aquariums, and which influences the way they operate...and look.

This isn't the best way to run an aquarium.

It's just a way to run an aquarium.

The botanical method is not an excuse for laziness, nor a license to abandon common sense, either. You still have to do some work, and to make the effort to understand why you're doing what you're doing. And yes- Nature will rightfully kick your ass if you try to circumvent her laws. You are entirely to blame if your tank fails...

Ouch! 

Perhaps it's not what you would expect to hear, but it's true. When I do something stupid, take a big risk without considering the consequences, I occasionally get my ass handed to me by Mother Nature. And I'm entirely okay with that. I deserve it. I learn from it. And, yeah- there IS a certain amount of risk to taking a slightly different approach. Sometimes, shit happens even when you're doing what you feel is the right thing.

Not everyone wants that. It's 100% understandable. Yet, it's what you expose yourself to when you really "...stand with Nature!"

And, there's also the way we look at things that most hobbyists view as "problems." 

When people are going through "stuff" in their tanks, like algae blooms, etc., tradition in the hobby dictates "corrective action" taken by the aquarist. It's seen as a huge problem. It needs to be corrected. Often times, if we look at the "problem" objectively, it's simply Nature responding, as She has for eons, to a set of parameters which favor one life form over another. Our version of "corrective action" is to find out what is causing the "undesired" issue, and simply allowing natural processes to help bring things back into a normal balance.

As we've discussed many times before, often, our "corrective actions" to "solve" some sort of "issue" usually involves...doing nothing. Yeah. Just waiting it out. Letting Nature correct things and bring the aquarium back on course- just like She's done in the wild aquatic habitats for millennia. Asking ourselves if what we are seeing is really a "problem" in the overall scheme of Nature- or just a "problem" to us as hobbyists, because we've labeled it as such.

It can be tough to wrap your head around that. Particularly after generations of hobby wisdom and practice telling you otherwise. Again, it's a mental shift that I couldn't possibly expect everyone to make or embrace. 

And you still have to apply some old-fashioned common sense to this approach...It's not, "stand by and watch as your aquarium bites the dust..."

In real problematic cases-extreme situations, like disease outbreaks, ammonia spikes, temperature drops, poisonings, etc.- intervention by the hobbyist is the absolute right call.

Standing by, waiting for an infectious disease to "run its course", is ridiculous. Assuming that the disinfectant that your housekeeper accidentally spilled in the tank will simply "work its way out of the system" is insane. However, for a bloom of biofilms, some cloudy water that can't be attributed to mismanagement on your part, or a little bit of algae, "waiting it out" is the best way to go in many cases, IMHO.

Many of these things we call "problems" are simply life forms reacting to opportunities and resources available to them. Nature seeks to balance things out, and these things are often a sign that Nature is "working on it.." Often, the "solution" we employ creates some other imbalance, and fails to contemplate that the "problem" is simply NOT a problem in the first place.

I've said it a hundred times and I'll say it again: I think that many of the things we label as "problems" in the aquarium problem receive that label because of the way they appear. Things which don't fit some hobby-imposed standard of aesthetics get labeled as "problems." IMHO, that's an absurdly incorrect, downright irrational point of view.

Looking at things we're unfamiliar with, or that we find unattractive because of hobby "norms" as "problems" deters us from evolving and moving ahead, IMHO. It sets up artificial "roadblocks" on our journey that aren't always necessary.

We need to look at these things as opportunities. Yes, opportunities to figure out what role they play in the ecology of natural aquatic ecosystems- and in our aquaruims. We need to look for ways to incorporate, rather than eliminate them from our tanks. 

Because when we incorporate natural processes and functions into our tanks, we're doing the very best possible job at advancing the "state of the art" in aquarium keeping. More than we ever could by studying some rock arranging technique or sharing how to glue wood pieces together to achieve a certain "look."

This position will not win me any friends in some corners of the larger aquarium community. It will definitely anger almost everyone who's ever written a "How to solve your _________ problem"-type article for beginners, and it will certainly piss off some manufacturers of "solutions" for all sorts of "problems" with our aquariums.

Why? 

Well, first, because it's wildly unorthodox. 

It is a sort of different take on being proactive in the hobby. Our version of "proactive" is to set up your aquarium to work with Nature from the start- to allow Her the "space" to do her thing. It's not designed to employ numerous technical "props", additives, and complex procedures at every step. One thing we do recommend, however, is to perform regular small water exchanges on your aquariums. They make sense, especially in a closed ecosystem such as an aquarium. That's one "tradition"- and apparently not a popular one with many hobbyists- that we are behind 100%! (It figures, right? We embrace the most unpopular "tradition" in the hobby!)

We espouse studying natural aquatic habitats- their influences and functions- and how they formed, as the "model" for our aquariums. Anyone can tell you to "use this filter", "add this additive", etc. Only Nature can tell you, with authority, to allow THIS or THAT to occur in your aquarium, because that what She wants.

We ceded some of the work to Nature. We accept Her actions. Work with them, instead of resist them.

Yeah, it's a huge mental shift.

Also, it's not popular to advocate for something without some "plug-and-play" solution these days. Telling a hobbyist to study what the cause of the "algae problem" in his or her aquarium could and then to simply "wait it out" or take subtle actions until such time as the system "rebalances" itself is a wildly unpopular approach, I'll admit.

Sure, if you see something obvious- like, you're dumping a whole pack of frozen brine shrimp into your tank at every feeding, you could curtail that ASAP! But embarking on some crazy procedure to exchange 90% of the water in your tank, or scrubbing and siphoning the "detritus" out of every centimeter of sand is, IMHO, a fool's errand, which will only result in a longer "recovery time." (don't get me started on detritus, btw...)

In my opinion, most of what we label as "problems" in the aquarium are the result of environmental lapses or imbalances caused either by something your tank is efficient in- or has too much of. It's that simple. And I believe that there are other ways to tackle these issues than simply reaching for "Product A" or whatever.

Yeah.

That's simply NOT how great botanical-method aquariums are conceived, created, or managed.

They're created to facilitate and take advantage of natural processes- regardless of how they look initially. Function first.

In my (admittedly biased) opinion, a botanical-method aquarium is perhaps one of the best ways to bring Nature into our home! To blur the lines between Nature and aquarium. Really. Sure, planted aquariums give us a similar challenge...but the botanical-method aquarium challenges us in different ways. It tasks us to understand and accept Nature in all of its beauty. And yeah, it makes us accept that there IS beauty in things like decomposition, biofilm, detritus, and algal growth. Things which we as aquarists might have been "indoctrinated" to loathe over the years..

We just have let go sometimes, and trust in Nature to move stuff along the correct path.

Nature finds a way. Nature knows how to do this.

Again- problems are only "problems" if we interpret them as such. When we see something we didn't expect to happen in our tanks occur, the question to ask ourselves might not be, "What's the problem?" Rather, it might be, "IS there are problem?"

Look, it's not like we are trying to create warp drive or foster nuclear fusion. Nothing about the botanical-method approach is even remotely difficult or hard to execute from a technical standpoint. In fact, the only "hard" part of this whole approach is making those mental shifts. Letting go of old notions or preconceptions; that sort of thing.  

Our practice and its underlying philosophy is not really that earth-shattering.

But it is an example of an approach- one of many in our hobby, which simply requires us to look at what exactly we want to accomplish, understand what it is just a bit, and to develop a mind set and practical procedures to work within the requirements and parameters laid out by Nature- in our aquariums. It's still very much a "work in progress", but we're well on the way to making truly natural, botanical-method aquariums far more common in the hobby. 

Perhaps not traditional...but very exciting!

We can find comfort in forging new paths. What we don't yet know and understand is every bit as compelling as what we do.

Think about that.

Stay thoughtful. Stay creative. Stay curious. Stay driven...

And Stay Wet.

 

Scott Fellman

Tannin Aquatics

 

 

 

 

 

Just can't stay away...Well, maybe I can, for now.

Welcome to my mind...

Today's little tale is something which many of you may relate to. Perhaps some of you can't relate to it. Others might simply gain value by remaining comfortably at a distance and watching how this unfolds.

It's all good.

I'm now in the final weeks before setting up some new tanks in my home office in my newly remodeled home for the first time in 18 MONTHS! I'm brimming over with new and old ideas, and at least two or three tanks will be going up in a fairly short period of time...

(Yeah, I'm charging my MacBook from the power strip inside that stand...I mean, I'm not running the tank yet, so why waste the outlet? 😆)

It's really exciting for me.

In fact, it's probably the most excited I've been in the hobby in years. Doing without my usual tanks has been agonizing. Like with many of you, aquariums are a huge part of my life and my sanity! I'm stoked to be getting underway again! 

Among other things, the intention is to create a new variation of my brackish water mangrove habitat... A long awaited, smaller, shallow version of the highly successful botanical-style brackish tank I created a few years ago. 

And of course, whenever there is salt in the equation, my mind begins to wander...

Even though I'm set up to do a full-blown, high-end coral tank early next year, for some reason I simply can't hold back against the idea of just "going all the way" and creating a mangrove-centric marine tank instead of brackish...

I mean, I've been steadily nudging up the specific gravity to 1.010 in my temporary mangrove tank from 1.005.. It IS getting closer all the time to 1.025...full strength marine water...And I never did a "mangrove-first" saltwater tank before...It's something I've been craving to do for years, rather than having them sort of hanging in the background as "supporting players" to the corals...

Of course, the idea was that this time, I'd make them the stars, with perhaps a few sand-dwelling corals like Goniopora, or maybe Catalaphyllia or Cynarina. Or-maybe a small Sarcophyon or some other soft corals... Fishes would likely be some Pajama Cardinal Fish and/or captive-bred Mandarin Dragonets or something small, like gobies...And some seagrasses! Not just a "reef tank with a mangrove in it", which has been done-  or at least, contemplated by pretty much every reefer who's ever lived, lol.

Nope, this is a true mangrove-focused marine aquarium. 

Urghhh..!

It's too tempting to not do this. Right?

So, it would be an incredibly biologically rich, diverse, nitrate-loving saltwater tank...a bit different than the way I'll do my coral focused tank, so there is some fun freedom here!

I've got a great little all-in-one tank to play with- an Innovative Marine "Fusion Lagoon 25", with integrated overflow, a wide foot print, and a DC pump ready to go. And I can swap out my Kessil A80 "Tuna Sun" for that cool Kessil A80 "Tuna Blue" with a spectral controller that has just been staring at me from the box for over a year...Yeah, gear... That thing that reefers love...playing with cool gear...I mean, just having a simple, coral-growth-capable little light for this idea is motivation enough for the hardcore reefer in me.

Can't...resist... I just can't stay away...Must execute...

Or, can I?

I mean, I should do another brackish tank.Yeah, I should, right? Or, maybe not... I dunno...

It would be so easy to ease back into my saltwater roots a bit with a significantly different approach to saltwater than I've done in a decade. Bring the whole Tannin philosophy in. Hell, I've been imagining doing a muddy, mangrove and coral estuary-type tank for years, but my coral-focused mindset wouldn't allow it. I never took the time to execute on this idea, being so busy with them as co-owner of a successful coral propagation/import business.

 

But, that was then.

And now, with this empty tank, what seems like the right situation, and the idea bubbling up once again, it's becoming irresistible. Time to "scratch the itch", right? And yeah, my reefing friends are teasing me a bit with that "peer pressure" sort of thing to do it that only friends can do.

So the idea I had is ridiculously simple:

A deep substrate of NatureBase "Mangal", perhaps topped or mixed with some fine aragonite sand...Modest water flow, perhaps not even supplementing the return flow from the system pump. Modest LED lighting in the 10,000K range for the corals. The aquarium is situated in a locale which receives more than enough ambient natural light to grow the mangroves...in fact, all they've received for almost 3 years is natural room-filtered sunlight and they have grown from small propagules to beautiful seedlings!

 

I think the biggest challenge in this tank would be restraint...because it's small (only 25 US gallons- squarely in the "nano" category for a "reef" tank), I simply can't keep a whole bunch of coral and fishes in it. And the bioload in a modest sized tank would reflect that. The ecological diversity, however, is where I'm focusing with this one. 

Coral-wise, I think I'd be focusing on one two  that I really love- Goniopora or Catalaphyllia.

Wow, the familiar alluring glow of "Windex blue" LED light and that "reef smell" are seared into my psyche - it would be so nice to experience them again, right?

Ahh, then there is the thing that gets me. Stops the whole fantasy in it's tracks. Brings me back from my warm, ignorant bliss into the cold light of reality.

I mean, a small aquarium with relatively aggressive corals like the two mentioned above is basically a self-limiting system. OR should I say, it requires the hobbyist to "cool his or her jets", as the expression goes. Unless I want to go "monospecific", the tank runs the risk of turning into a chemical warfare zone, with the super-aggressive Catalaphyllia or Goniopora essentially chemically beating the living shit out of anything else I'd put in there into submission. 

That means, little in the way of coral diversity if I want to be responsible. And I do, of course. And really, when you take into account the displacement for substrate, this "25 gallons" really becomes like, I dunno- maybe 18-19 gallons. Squarely in the "nano"marine  tank zone- the idea of which has always turned me off. Why?

Not because they're bad. They're not. 

It's because I'd be too limited to execute the plan the way I want to. The way it should be executed in an aquarium.

And dealing with a heavy set of ecological factors in a tiny, well-illuminated, not fully-equipped "reef" tank is a recipe for algal blooms and all of the stuff which takes away from the fun of having a unique system, in my mind. I mean, sure, I can handle that stuff- I have many times. Yet, what I can't handle is being soooo limited and size-restricted. Going in knowingly limited in both scope and equipment is a bad handicap for an enjoyable reef experience, IMHO. Yeah, it's against my mindset with reefs to go this route. I suppose that it can be argued that it shouldn't be- tons of successful hobbyists run gorgeous "nano reefs" and derive great pleasure from them.

But they're not me. I'm not them. And I don't feel like outfitting the crap out of a 25-gallon tank to get the system the way I want it.

Ahh, a "champagne problem" for this little aquarium brat, huh? 😂

There is a lesson here:

The enormous power and value which self-awareness brings to us as hobbyists.

I simply couldn't enjoy this tank in that format because it goes against everything that I've previously believed in. I couldn't take this "vanity detour" simply because I didn't want to wait until Spring, as I've planned, to "get my reefing on."

I mean, that's totally against my "patience first" philosophy, isn't' it?

Yeah, seriously. Just super-lame, IMHO. Lowkey STUPID. A surefire recipe for not having fun. And a deviation from patience. Hell, I waited a year and half to have "real" tanks again- what's another few months to have the "crown jewel" of my home aquarium collection properly in place?

I'm going to have my full-blown coral tank soon enough.

And the "Mangrove-centric" marine tank? Maybe some other time. It'd still a really good idea. Every one of my reefing friends wanted me to do it. And me, Scott Fellman- the "Once and Future Reefer"- 7-time MACNA speaker, coral vendor, reef world "A-lister"... What do I want? That's what really matters. And all of that other nonsense..Will I ever get back to that?

Of course.

Well, at least, the practicing "reefer" part. Who the fuck cares about the "celebrity" bit? It was fun, but never the motivation. "Check the ego part, Fellman."

Just being a "practicing reefer" is a lot of fun...

But this isn't the time for it. I have a different journey to take. Back to the mangal for me.

The brackish execution is something that is super important to me...and, according to feedback I've received from our community- to many of YOU as well. More hobbyists want to learn about this. Brackish is one of those hobby segments that has simply not gotten the attention it has deserved for many years, and to NOT proceed with my "V2.0" brackish tank would be doing the hobby a bit of a...disservice. Yeah, I need to show others how cool and fun this niche segment of the hobby can be when executed a bit differently.

Really!

That's how I think!

I mean, it sounds a bit arrogant, I suppose- but the reality is that most brackish tanks I've seen for decades are, well- shitty. And boring.  And as you know- we don't do "shitty and boring" around here. 

(Not that I haven't ever done "shitty and boring", mind you- but I have no intentions of ever doing that again- if I can avoid it!).

Tannin was founded on the very idea of doing stuff a bit differently than it has been in the past. About pushing boundaries, poking the metaphorical beehive, and just generally approaching things in unique ways. To not do this is a violation of my own ethos, and the founding principles of our company!

Our mission statement in our business plan is, literally, "Do cool shit."

I'm totally serious. 

And we WILL do cool shit.

And  what about the "mental detour" I took- multiple days of scheming, researching, even talking to my fellow reef geeks...? It was a good exercise. A great exercise, really. One which pushed me to do that "imagineering" as Disney used to call it- to think about ways to execute ideas that formerly were just..ideas. It wasn't a waste of time at all.

I enjoyed all of it.

 

And I came really, really close to doing it...

I mean, sure, I know that I could have pulled it off.

But in the end, it wasn't right.

It would be abandoning my ideals and principles while engaging in what at best would be a journey into an area that wouldn't have really fulfilled me. Now, there is a lot to be said about the occasional "mental detour"...I mean, always indulge yourself, scheme, think through, research, talk about it with friends...But in the end, you HAVE to listen to yourself; to do what makes your heart really sing. 

To do anything less is to deny yourself- and maybe even others- the beauty, joy, and inspiration that can only come when intention, ideas, philosophy, and execution synch up.

Sure, sometimes you actually will have to take the detour. You may and up loving it and creating something brilliant. Or you may be disheartened by it. You never know until you push right to the edge- or further sometimes. Ask anyone who's been there before.

Yet, in this instance, for the reasons we just talked about, and many more that I haven't even begun to articulate here, I'm staying "on plan." I know that this is where I really want to go with this tank at this time. I know that's where I need- and want- to be.

I hope that this little journey into my personal mindset has touched you somehow. I hope that it brought you value. Maybe, perhaps- it gave you the courage to move forward on that little detour, Or, perhaps it made you rethink- and yanked you back from the ledge. Perhaps it simply made you laugh and be thankful that you're not me! 😆

Regardless of how this little discussion touched you today- I hope that it taught you the value of listening to yourself in the hobby. Always.

Yeah, it's time for the cliched Steve Jobs quote- 'cause it's damn applicable in this instance, isn't it?

"Your time is limited, so don't waste it living someone else's life. Don't be trapped by dogma - which is living with the results of other people's thinking. Don't let the noise of others' opinions drown out your own inner voice."

So, yeah. Stay on task. Stay brave. Stay thoughtful. Stay diligent. Stay creative. Stay patient...

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