The Tint

Race to the bottom...

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Amazing stuff.

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

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

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

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

Let's think about this for just a second.

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

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

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

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

And then there's the question of nitrate. 

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

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

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

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

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

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

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

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

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

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

Damn, did I just quote myself?

I did!

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

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

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

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

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

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

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

Again, look to Nature...

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

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

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

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

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

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

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

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

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

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

Yeah.

Interesting.

Let's state it one more time:

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

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

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

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

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

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

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

Leaf litter- yet again. 

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

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

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

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

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

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

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

Nutrient cycling.

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

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

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

Substrates are not just "the bottom." 

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

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

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

And Stay Wet.

Scott Fellman

Tannin Aquaitcs 

"Operating" our aquariums with seasonal and ecological practices.

One of the great joys in creating and working with botanical method aquairums is that we have such a wide variety of natural habitats to take inspiration from. And, as we've discussed here over the years, it's not just types of natural aquatic habitats or specific locales- it's seasons and cycles that we can emulate in our tanks as well.

I find it fascinating to think about how we can emulate the environmental characteristics of aquatic habitats during certain times of the year, such as the "wet" and "dry" seasons...and the idea of actually "operating" your aquarium to spur the environmental changes which take place during these transitions.

Do we create true seasonal variations for our aquariums? I mean, changing up lighting duration, intensity, angles, colors, increasing/decreasing water levels or flow?

With all of the high tech LED lighting systems, electronically controlled pumps; even programmable heaters- we can vary environmental conditions to mimic what occurs in our fishes' natural habitats during seasonal changes as never before. I think it would be very interesting to see what kinds of results we could get with our fishes if we went further into environmental manipulations than we have been able to before.

I mean, sure, hobbyists have been dropping or increasing temps for spawning fishes forever, and you'll see hobbyists play with light durations. Ask any Corydoras breeder. However, these are typically only in the context of defined controlled breeding experiments.

Why not simply research and match the seasonal changes in their habitat and vary them accordingly "just because", and see if you achieve different results?

We've examined the interesting Igapo and Varzea habitats of The Amazon for years now, and how these seasonally-inundated forest floors ebb and flow with aquatic life during various seasons.

And, with the "Urban Igapo", we've "operated" tanks on "wet season/dry season" cycles for a few years now, enjoying very interesting results.

I think it would be pretty amazing to incorporate gradual seasonal changes in our botanical method aquariums, to slowly increase/decrease water levels, temperature, and lighting to mimic the rainy/dry seasonal cycles which affect this habitat.

What secrets could be unlocked?

How would you approach this?

You'd need some real-item or historical weather data from the area which you're attempting to replicate, but that's readily available from multiple sources online. Then, you could literally tell yourself during the planning phases of your next tank that, "This aquarium will be set up to replicate the environmental conditions of the Igarape Panemeo in May"- and just run with it.

What are some of the factors that you'd take into account when planning such a tank? Here are just a few to get you started:

-water temperature

-ph

-water depth

-flow rate

-lighting conditions

-percentage of coverage of aquatic plants (if applicable)

-substrate composition and depth

-leaf litter accumulation

-density of fish population

-diversity of fish population 

-food types

...And the list can go on and on and on. The idea being to not just "capture a moment in time" in your aquarium, but to pick up and run with it from there! 

Yes, we love the concept of seasonality in our botanical method world- but not just because they create interesting aesthetic effects- but because replicating seasonal changes brings out interesting behaviors and may yield health benefits for our fishes that we may have not previously considered.

The implications of seasonality in both the natural environment- and, I believe- in our aquariums- can be quite profound.

Amazonian seasonality, for example, is marked by river-level fluctuation, also known as "seasonal pulses." The average annual river-level fluctuations in the Amazon Basin can range from approximately 12'-45' /4–15m!!!  Scientists know this, because River-water-level data has been collected in some parts of the Brazilian Amazon for more than a century! The larger Amazonian rivers fall into to what is known as a “flood pulse”, and are actually due to relatively predictable tidal surge.

And of course, when the water levels rise, the fish populations are affected in many ways. Rivers overflow into surrounding forests and plains, turning the formerly terrestrial landscape into an aquatic habitat once again.

Besides just knowing the physical environmental impacts on our fishes' habitats, what can we learn from these seasonal inundations?

Well, for one thing, we can observe their impact on the diets of our fishes.

In general, fish/invertebrates, detritus and insects form the most important food resources supporting the fish communities in both wet and dry seasons, but the proportions of invertebrates, fruits, and fish are reduced during the low water season. Individual fish species exhibit diet changes between high water and low water seasons in these areas...an interesting adaptation and possible application for hobbyists?

Well, think about the results from one study of gut-content analysis form some herbivorous Amazonian fishes in both the wet and dry seasons: The consumption of fruits in Mylossoma and Colossoma species (big ass fishes, I know) was significantly less during the low water periods, and  their diet was changed, with these materials substituted by plant parts and invertebrates, which were more abundant.

Tropical fishes, in general, change their diets in different seasons in these habitats to take advantage of the resources available to them.

Fruit-eating, as we just discussed, is significantly reduced during the low water period when the fruit sources in the forests are not readily accessible to the fish. During these periods of time, fruit eating fishes ("frugivores") consume more seeds than fruits, and supplement their diets with foods like leaves, detritus, and plankton.

Interestingly, even the known "gazers", like Leporinus, were found to consume a greater proportion of materials like seeds during the low water season.

The availability of different food resources at different times of the year will necessitate adaptability in fishes in order to assure their survival. Mud and algal growth on plants, rocks, submerged trees, etc. is quite abundant in these waters at various times of the year. Mud and detritus are transported via the overflowing rivers into flooded areas, and contribute to the forest leaf litter and other botanical materials, becoming nutrient sources which contribute to the growth of this epiphytic algae. 

During the lower water periods, this "organic layer" helps compensate for the shortage of other food sources. And of course, this layer comprises an ecological habitat for a variety of organisms at multiple "trophic levels."

And of course, there's the "allochthonous input"- materials imported into the habitat from outside of it...When the water is at a high period and the forests are inundated, many terrestrial insects fall into the water and are consumed by fishes. In general, insects- both terrestrial and aquatic, support a large community of fishes.

So, it goes without saying that the importance of insects and fruits- which are essentially derived from the flooded forests, are reduced during the dry season when fishes are confined to open water and feed on different materials, as we just discussed. 

And in turn, fishes feed on many of these organisms. The guys on the lower end of the food chain- bacterial biofilms, algal mats, and fungal growths, have a disproportionately important role in the food webs in these habitats! In fact, fungi are the key to the food chain in many tropical stream ecosystems. The relatively abundant detritus produced by the leaf litter is a very important part of the tropical stream food web.

Interestingly, some research has suggested that the decomposition of leaf litter in igapo forests is facilitated by terrestrial insects during the "dry phase", and that the periodic flooding of this habitat actually slows down the decomposition of the leaf litter (relatively speaking) because of the periodic elimination of these insects during the inundation.

And, many of the organisms which survive the inundation feed off of the detritus and use the leaf substratum for shelter instead of directly feeding on it, further slowing down the decomposition process.

AsI just touched on, much of the important input of nutrients into these habitats consists of the leaf litter and of the fungi that decompose this litter, so the bulk of the fauna found there is concentrated in accumulations of submerged litter.  

And the nutrients that are released into the water as a result of the decomposition of this leaf litter do not "go into solution" in the water, but are tied up throughout in the "food web" comprised of the aquatic organisms which reside in these habitats.

This concept is foundational to our interpretation of the botanical method aquarium.

So I wonder...

Is part of the key to successfully conditioning and breeding some of the fishes found in these habitats altering their diets to mimic the seasonal importance/scarcity of various food items? In other words, feeding more insects at one time of the year, and perhaps allowing fishes to graze on detritus and biocover at other times?

And, you probably already know the answer to this question:

Is the concept of creating a "food producing" aquarium, complete with detritus, natural mud, and an abundance of decomposing botanical materials, a key to creating a more true realistic feeding dynamic, as well as an "aesthetically functional" aquarium?

Well, hell yes! 

On a practical level, our botanical method aquariums function much like the habitats which they purport to represent, famously recruit biofilm and fungal growths, which we have discussed ad nasueum here over the years. These are nutritious, natural food sources for most fishes and invertebrates.

And of course, there are the associated microorganisms which feed on the decomposing botanicals and leaves and their resulting detritus.

Having some decomposing leaves, botanicals, and detritus helps foster supplemental food sources. Period.

And you don't need special botanicals, leaves, curated packs of botanicals, additives, or gear from us or anyone to create the stuff! Nature will do it all for you using whatever botanical materials you add to your aquarium! 

Apparently, the years of us beating this shit into your head here on "The Tint" and elsewhere are finally striking a chord. There are literally people posting pics of their botanical method aquariums on social media every week with hashtags like #detriusthursday or whatever, preaching the benefits of the stuff that we've reviled as a hobby for a century!

That absolutely cracked me up the first time I saw people posting that. Five years ago, people literally called me an idiot online for telling hobbyists to celebrate the stuff...Now, it's a freaking hashtag. It's some weird shit, I tell you...gratifying to see, but really weird!

Now, we've briefly talked about how decomposing leaf litter and the resulting detritus it produces supports population of "infusoria"- a collective term used to describe minute aquatic creatures such as ciliates, euglenoids, protozoa, unicellular algae and small invertebrates that exist in freshwater ecosystems.

And there is much to explore on this topic. It's no secret, or surprise- to most aquarists who've played with botanicals, that a tank with a healthy leaf litter component is a pretty good place for the rearing of fry of species associated with blackwater environments!

It's been observed by many aquarists, particularly those who breed loricariids, gouramis, bettas, and characins, that the fry have significantly higher survival rates when reared in systems with leaves and other botanical present. This is significant...I'm sure some success from this could be attributed to the population of infusoria, etc. present within the system as the leaves break down.

And the insights gained by seeing first hand how fishes have adapted to the seasonal changes, and have made them part of their life cycle are invaluable to our aquarium practice.

It's an oft-repeated challenge I toss out to you- the adventurers, innovators, and bold practitioners of the aquarium hobby: follow Nature's lead whenever possible, and see where it takes you. Leave no leaf unturned, no piece of wood unstudied...push out the boundaries and blur the lines between Nature and aquarium.

Follow the seasons.

And place the aesthetic component of our botanical method aquarium practice at a lower level of importance than the function.

I'm fairly certain that this idea will make me even less popular with some in the aquarium hobby crowd who feel that the descriptor of "natural" is their exclusive purview, and that aesthetics reign supreme..Hey, I love the look of well-crafted tanks as much as anyone...but let's face it, a truly "natural" aquarium needs to embrace stuff like detritus, mud, decomposing botanical materials, varying water tint and clarity, etc.

Yes, the aesthetics of botanical method tanks might not be everyone's cup of tea, but the possibilities for creating more self-sustaining, ecologically sound microcosms are numerous, and the potential benefits for fishes are many. 

It goes back to some of the stuff we've talked about before over the years here, like "pre-stocking"aquariums with lower life forms before adding your fishes- or at least attempting to foster the growth of aquatic insects and crustaceans, encouraging the complete decomposition of leaves and botanical materials, allowing biocover ("aufwuchs") to accumulate on rocks, substrate, and wood within the aquarium, utilization of a refugium, etc.during the startup phases of your tank.

All of these things are worth investigating when we look at them from a "functionality" perspective, and make the "mental shift" to visualize why a real aquatic habitat looks like this, and how its elegance and natural beauty can be every bit as attractive as the super pristine, highly-controlled, artificially laid out "plant-centric" 'scapes that dominate the minds of most aquarists when they hear the words "natural" and "aquarium" together!

Particularly when the "function" provides benefits for our animals that we wouldn't appreciate , or even see- otherwise.

At Tannin, we've pushed rather unconventional hobby viewpoints since our founding in 2015. As an aquarist, I've had these viewpoints on the hobby for decades. A desire to accept the history of our hobby, to understand how "best practices" and techniques came into being, while being tempered by a strong desire to question and look at things a bit differently. To see if maybe there's a different- or perhaps-better-way to accomplish stuff.

Most of my time in the hobby has been occupied by looking at how Nature works, and seeing if there is a way to replicate some of Her processes in the aquarium, despite the aesthetics of the processes involved, or even the results.

As a result, I've learned to appreciate Nature as She is, and have long ago given up much of my "aquarium-trained" sensibilities to "edit" or polish out stuff I see in my aquariums, simply because it doesn't fit the prevailing aesthetic sensibilities of the aquarium hobby. Now, it doesn't mean that I don't care how things look...of course not!

Rather, it means that I've accepted a different aesthetic- one that, for better or worse in some people's minds- more accurately reflects what natural aquatic habitats really look like. 

And the idea of replicating the seasonal changes in our aquariums is driven not primarily from aesthetics- but from function. 

To sort of put a bit of a bow on this now rather unwieldy discussion about fostering and managing our own versions of seasonal ecological systems in our aquariums, let's just revisit once again how botanical materials accomplish this in our aquariums.

The idea that we are adding these materials not only to influence the aquatic environment in our aquariums, but to provide food and sustenance for a wide variety of organisms, not just our fishes. The fundamental essence of the botanical-method aquarium is that the use of these materials provide the foundation of an ecosystem.

The essence.

Just like they are in Nature. 

And the primary process which drives this closed ecosystem is... decomposition.

Decomposition of leaves and botanicals not only imparts the substances contained within them (lignin, organic acids, and tannins, just to name a few) to the water- it serves to nourish bacteria, fungi, and other microorganisms and crustaceans, facilitating  basic "food web" within the botanical-method aquarium- if we allow it to!

Decomposition of plant matter-leaves and botanicals- occurs in several stages.

It starts with leaching -soluble carbon compounds are liberated during this process. Another early process is physical breakup or fragmentation of the plant material into smaller pieces, which have greater surface area for colonization by microbes.

And of course, the ultimate "state" to which leaves and other botanical materials "evolve" to is our old friend...detritus.

And of course, that very word- as we've mentioned many times here, including just minutes ago- has frightened and motivated many hobbyists over the years into removing as much of the stuff as possible from their aquariums whenever and wherever it appears.

Siphoning detritus is a sort of "thing" that we are asked about near constantly. This makes perfect sense, of course, because our aquariums- by virtue of the materials they utilize- produce substantial amounts of this stuff.

Now, the idea of "detritus" takes on different meanings in our botanical-method aquariums...Our "aquarium definition" of "detritus" is typically agreed to be dead particulate matter, including fecal material, dead organisms, mucous, etc.

And bacteria and other microorganisms will colonize this stuff and decompose/remineralize it, essentially "completing" the cycle.

And, despite their impermanence, these materials function as diverse harbors of life, ranging from fungal and biofilm mats, to algae, to micro crustaceans and even epiphytic plants. Decomposing leaves, seed pods, and tree branches make up the substrate for a complex web of life which helps the fishes that we're so fascinated by flourish throughout the various seasons.

And, if you look at them objectively and carefully, these assemblages-and the processes which form them- are beautiful. We would be well-advised to let them do their work unmolested.

On a purely practical level, these processes accomplish the most in our aquariums if we let Nature do her work without excessive intervention.

An example? How about our approach towards preparing natural materials for use in our tanks:

After decades of playing with botanical method aquariums, I'm thinking that we should do less and less preparation of certain botanical materials-specifically, wood- to encourage a slower breakdown and colonization by beneficial bacteria and fungal growths.

The "rap" on wood has always been that it gives off a lot of tint-producing tannins, much to the collective freak-out of non-botanical-method aquarium fans. However, to us, all those extra tannins are not much of an issue, right? Weigh down the wood, and let it "cure" in situ before adding your fishes!

And then there is the whole concept of getting fishes into the tank as quickly as possible.

Like, why?

We should slow our roll.

I've written and spoken about this idea before, as no doubt many of you have: Adding botanical materials to your tank, and "pre-colonizing"with beneficial life forms BEFORE you ever think of adding fishes. A way to sort of get the system "broken in", with a functioning little "food web" and some natural nutrient export processes in place.

A chance for the life forms that would otherwise likely fall prey to the fishes to get a "foothold" and multiply, to help create a sustainable population of self-generating prey items for your fishes.

And that's a fundamental thing for us "recruiting" and nurturing the community of organisms which support our aquariums. The whole foundation of the botanical-method aquarium is the very materials- botanicals, soils, and wood- which comprise the "infrastructure" of our aquariums.The botanicals create a physical and chemical environment which supports these life forms, allowing them to flourish and support the life forms above them. 

From there, we can "operate" our aquariums in any manner of ways.

Nature provides some really incredible inspiration for this stuff, doesn't it? Marshland and flooded plains and forests along rivers are like the "poster children" for seasonal change in the tropics.

Flood pulses in these habitats easily enable large-scale "transfers" of nutrients and food items between the terrestrial and aquatic environment. This is of huge importance to the ecosystem. As we've touched on before, aquatic food webs in the Amazon area (and in other tropical ecosystems) are very strongly influenced by the input of terrestrial materials, and this is really an important point for those of us interested in creating more natural aquatic displays and microcosms for the fishes we wish to keep.

Because the aquatic ecology is driven by the surrounding terrestrial habitats seasonally, the impact of leaves which fall  into the aquatic habitats is very important. 

What makes leaves fall off the trees in the first place? Well, it's simple- er, rather complex...but I suppose it's simple, too. Essentially, the tree "commands" leaves to fall off the tree, by creating specialized cells which appear where the leaf stem of the leaves meet the branches. Known as "abscission" cells. for word junkies, they actually have the same Latin root as the word "scissors",  which, of course, implies that these cells are designed to make a cut! 

And, in the tropical species of trees, the leaf drop is important to the surrounding environment. The nutrients are typically bound up in the leaves, so a regular release of leaves by the trees helps replenish the minerals and nutrients which are typically depleted from eons of leaching into the surrounding forests.

And the rapid nutrient depletion, by the way, is why it's not healthy to burn tropical forests- the release of nutrients as a result of fire is so rapid, that the habitat cannot process it, and in essence, the nutrients are lost forever.

Now, interestingly enough, most tropical forest trees are classified as "evergreens", and don't have a specific seasonal leaf drop like the "deciduous" trees than many of us are more familiar with do...Rather, they replace their leaves gradually throughout the year as the leaves age and subsequently fall off the trees.

The implication here?

There is a more-or-less continuous "supply" of leaves falling off into the jungles and waterways in these habitats throughout the year, which is why you'll see leaves at varying stages of decomposition in tropical streams. It's also why leaf litter banks may be almost "permanent" structures within some of these bodies of water!

Here's an easy "seasonal" experiment for you to try:

Manage and replicate this in the aquarium by adding leaves at different times of the year..increasing the quantities in some months and backing off during others. It's a relatively simple process with possible profound implications for aquariums.

And it makes me wonder...

What if we stopped replacing leaves and even lowered water levels or decreased water exchanges in our tanks to correspond to, for example, the Amazonian dry season (June to December)? What would it do?

If you consider that many fishes tend to spawn in the "dry" season, concentrating in the shallow waters, could this have implications for breeding or growth in fishes?

I think so.

Just a few easy ideas...each with a promise and a potential to change the way we manage botanical method aquariums, and impact the way we look at so-called "natural" aquariums in the first place!

And, with all of the research data from the wild habitats of our fishes available easier than ever before, the time is right to start these bold experiments!

Obviously, there is still much to learn, and of course, the bigger question that many will ask, "What is the advantage?" 

Well, that's all part of the fun...we can play a hunch, but we won't know for certain until we really delve into this stuff!

Who's in?

Stay thoughtful. Stay curious. Stay engaged. Stay innovative. Stay diligent...

And Stay Wet.

Scott Fellman

Tannin Aquatics 

As the seasons pass...

Every Corydoras breeder knows something that we all should know:

Environmental manipulations create unique opportunities to facilitate behavioral changes in our fishes.

It's hardly an earth-shattering idea in the aquarium hobby, but I think that the concept of "seasonal" environmental manipulation deserves some additional consideration.

It's been known for decades that environmental changes to the aquatic environment caused by weather (particularly "wet" or "dry" seasons/events) can stimulate fishes into spawning. 

As a fish geek keen on not only replicating the look of our fishes' wild habitats, but as much of the "function" as possible, I can't help myself but to ponder the possibilities for greater success by manipulating the aquarium environment to simulate what happens in the wild.

Probably the group of aquarists who has had the most experience and success at incorporating such environmental manipulations into their breeding procedures is Corydoras catfish enthusiasts! 

Many hobbyists who have bred Corydoras utilize the old trick of a 20%-30% water exchange with water that is up to 10° F cooler (6.5° C) than the aquarium water is normally maintained at. It seems almost like one of those, "Are you &^%$#@ crazy- a sudden lowering of temperature?"

However, it works, and you almost never hear of any fishes being lost as a result of such manipulations.

I often wondered what the rationale behind such a change was. My understanding is that it essentially is meant to mimic a rainstorm, in which an influx of cooler water is a feature. Makes sense. Weather conditions are such an important part of the life cycle of our fishes.

Still others attempt to simulate a "dry spell" by allowing the water quality to "degrade" somewhat (what exactly that means is open to interpretation!), while simultaneously increasing the aquarium temperature a degree or two. This is followed by a water exchange with softer water (ie; pure RO/DI), and resetting the tank temp to the tank's normal range of parameters.

The "variation" I have heard is to do the above procedure, accompanied by an increase in current via a filter return or powerhead, which simulates the increased water volume/flow brought on by the influx of "rain."

Clever.

Many breeders will fast their fishes a few days, followed by a big binge of food after the temperature drop, apparently simulating the increased amount of food in the native waters when rains come.

Still other hobbyists will reduce the pH of their aquarium water to stimulate breeding. And I suppose the rationale behind this is once again to simulate an influx of water from rain or other external sources...

Weather, once again.

And another trick I hear from my Cory breeder friends from time to time is the idea of tossing in a few alder cones into the tank/vessel where their breeders' eggs are incubating.

This decades-old practice is justified by the assertion that the alder cones possess some type of anti-fungal properties...not entirely off base with some of the scientific research we've found about the allegedly anti-microbial/antifungal properties of catappa leaves and such...

And of course, I hear/read of recommendations to use the aforementioned catappa leaves, oak leaves, and Magnolia leaves for just this purpose...

Interesting. 

Okay, cool.

Not really earth-shattering; however, it got me thinking about the whole idea of environmental manipulations as part of the routine "operation" of our botanical-mehtod aquariums.....Should we create true seasonal variations for our aquariums as part of our regular practice- not just when trying to spawn fishes? I mean, changing up lighting duration, intensity, angles, colors, increasing/decreasing water levels or flow?

With all of the high tech LED lighting systems, electronically controlled pumps; even advanced heaters- we can vary environmental conditions to mimic what occurs in our fishes' natural habitats during seasonal changes as never before. I think it would be very interesting to see what kinds of results we could get with our fishes if we went further into seasonal environmental manipulations than we have been able to before.

And of course, if we look at the natural habitats where many of our fishes originate, we see these seasonal changes having huge impact on the aquatic ecosystems. In The Amazon, for example, the high water season runs December through April.

And during the flooding season, the average temperature is 86 degrees F, around 12 degrees cooler than the dry season. And during the wet season, the streams and rivers can be between 6-7 meters higher on the average than they are during the dry season! 

And of course, there are more fruits, flowers, and insects during this time of year- important food items for many species of fishes.

And the dry season? Well, that obviously means lower water levels, higher temperatures, and abundance of fishes, most engaging in spawning activity. 

Mud and algal growth on plants, rocks, submerged trees, etc. is quite abundant in these waters at various times of the year. Mud and detritus are transported via the overflowing rivers into flooded areas, and contribute to the forest leaf litter and other botanical materials, coming nutrient sources which contribute to the growth of this epiphytic algae. 

During the lower water periods, this "organic layer" helps compensate for the shortage of other food sources. When the water is at a high period and the forests are inundated, many terrestrial insects fall into the water and are consumed by fishes. In general, insects- both terrestrial and aquatic, support a large community of fishes.

So, it goes without saying that the importance of insects and fruits- which are essentially derived from the flooded forests, are reduced during the dry season when fishes are confined to open water and feed on different materials. 

So I wonder...is part of the key to successfully conditioning and breeding some of the fishes found in these habitats altering their diets to mimic the seasonal importance/scarcity of various food items? In other words, feeding more insects at one time of the year, and perhaps allowing fishes to graze on detritus and biocover at other times?

And then, there are those fishes whose life cycle is intimately tied into the seasonal changes.

The killifishes.

Any annual or semi-annual killifish species enthusiast will tell you a dozen ways to dry-incubate eggs; again, a beautiful simulation of what happens in Nature...So much of the idea can be applicable to other areas of aquarium practice, right? 

Yeah... I think so.

It's pretty clear that factors such as the air, water and even soil temperatures, atmospheric humidity, the water level, the local winds as well as climatic variables have profound influence on the life cycle and reproductive behavior on the fishes that reside in these dynamic tropical environments! 

In my "Urban Igapo" experiments, we get to see a little microcosm of this whole seasonal process and the influences of "weather."

And of course, all of this ties into the intimate relationship between land and water, doesn't it?

There's been a fair amount of research and speculation by both scientists and hobbyists about the processes which occur when terrestrial materials like leaves and botanical items enter aquatic environments, and most of it is based upon field observations.

As hobbyists, we have a unique opportunity to observe firsthand the impact and affects of this material in our own aquariums! I love this aspect of our "practice", as it creates really interesting possibilities to embrace and create more naturally-functioning systems, while possibly even "validating" the field work done by scientists!

And of course, there are a lot of interesting bits of information that we can interpret from Nature when planning, creating, and operating our aquariums.

It goes without saying that there are implications for both the biology and chemistry of the aquatic habitats when leaves and other botanical materials enter them. Many of these are things that we as hobbyists observe every day in our aquariums!

Example?

A lab study I came upon found out that, when leaves are saturated in water, biofilm is at it's peak when other nutrients (i.e.; nitrate, phosphate, etc.) tested at their lowest limits. This is interesting to me, because it seems that, in our botanical method aquariums, biofilms tend to occur early on, when one would assume that these compounds are at their highest concentrations, right? And biofilms are essentially the byproduct of bacterial colonization, meaning that there must be a lot of "food" for the bacteria at some point if there is a lot of biofilm, right?

More questions...

Does this imply that the biofilms arrive on the scene and peak out really quickly; an indication that there is actually less nutrient in the water? Is the nutrient bound up in the biofilms? And when our fishes and other animals consume them, does this provide a significant source of sustenance for them?

Hmm...?

Oh, and here is another interesting observation:

When leaves fall into streams, field studies have shown that their nitrogen content typically will increase. Why is this important? Scientists see this as evidence of microbial colonization, which is correlated by a measured increase in oxygen consumption. This is interesting to me, because the rare "disasters" that we see in our tanks (when we do see them, of course, which fortunately isn't very often at all)- are usually caused by the hobbyist adding a really large quantity of leaves at once, resulting in the fishes gasping at the surface- a sign of...oxygen depletion?

Makes sense, right? 

These are interesting clues about the process of decomposition of leaves when they enter into our aquatic ecosystems. They have implications for our use of botanicals and the way we manage our aquariums. I think that the simple fact that pH and oxygen tend to go down quickly when leaves are  initially submerged in pure water during lab tests gives us an idea as to what to expect.

A lot of the initial environmental changes will happen rather rapidly, and then stabilize over time. Which of course, leads me to conclude that the development of sufficient populations of organisms to process the incoming botanical load is a critical part of the establishment of our botanical-method aquariums.

Fungal populations are as important in the process of breaking down leaves and botanical materials in water as are higher organisms, like insects and crustaceans, which function as "shredders." The “shredders” – the animals which feed upon the materials that fall into the streams, process this stuff into what scientists call “fine particulate organic matter.”

And that's where fungi and other microorganisms  make use of the leaves and materials, processing them into fine sediments. Allochthonous material can also include dissolved organic matter (DOM) carried into streams and re-distributed by water movement.

And the process happens surprisingly quickly.

In studies carried out in tropical  rainforests in Venezuela, decomposition rates were really fast, with 50% of leaf mass lost in less than 10 days! Interesting, but is it tremendously surprising to us as botanical-method aquarium enthusiasts? I mean, we see leaves begin to soften and break down in a matter of a couple of weeks- with complete breakdown happening typically in a month or so for many leaves.

And biofilms, fungi, and algae are still found in our aquariums in significant quantities throughout the process.

So, what's this all mean? What are the implications for aquariums? 

I think it means that we need to continue to foster the biological diversity of animals in our aquariums- embracing life at all levels- from bacteria to fungi to crustaceans to worms, and ultimately, our fishes...All forming the basis of a closed ecosystem, and perhaps a "food web" of sorts for our little aquatic microcosms. It's a very interesting  concept- a fascinating field for research for aquarists, and we all have the opportunity to participate in this on a most intimate level by simply observing what's happening in our aquariums every day!

We've talked about this very topic many times right here over the years, haven't we? I can't let it go.

Bioversity is interesting enough, but when you factor in seasonal changes and cycles, it becomes an almost "foundational" component for a new way of running our botanical-style aquariums.

Consider this:

The wet season in The Amazon runs from November to June. And it rains almost every day.

And what's really interesting is that the surrounding Amazon rain forest is estimated by some scientists to create as much as 50% of its own precipitation! It does this via the humidity present in the forest itself, from the water vapor present on plant leaves- which contributes to the formation of rain clouds.

Yeah, trees in the Amazon release enough moisture through photosynthesis to create low-level clouds and literally generate rain, according to a recent study published in the Proceedings of the National Academy of Sciences (U.S.)!

That's crazy.

But it makes a lot of sense, right?

Okay, that's a cool "cocktail party sound bite" and all, but what happens to the (aquatic) environment in which our fishes live in when it rains?

Well, for one thing, rain performs the dual function of diluting organics, while transporting more nutrient and materials across the ecosystem. What happens in many of the regions of Amazonia - and likewise, in many tropical locales worldwide-is the evolution of some of our most compelling environmental niches...

We've literally scratched the surface, and the opportunity to apply what we know about the climates and seasonal changes which occur where our fishes originate, and to incorporate, on a broader scale, the practices which our Corydoras-enthusiast friends employ on all sorts of fishes!

So much to learn, experiment with, and execute on.

Stay fascinated. Stay intrigued. Stay observant. Stay creative. Stay astute...

And Stay Wet.

Scott Fellman

Tannin Aquatics 

Behind the dynamics of the "Urban Igapo"

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

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

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

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

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

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

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

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

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

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

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

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

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

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

 Just add water, right?

Well, sort of.

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

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

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

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

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

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

Such a dismissive and judgmental attitude. 

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

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

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

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

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

You must be patient.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

And there are parallels in the management of aquariums.

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

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

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

Or not.

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

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

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

Nope. There is a lot of stuff to consider.

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

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

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

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

It happens in Nature, too!

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

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

And Stay Wet.

Scott Fellman

Tannin Aquatics  

The game of change...

As human beings, thankfully, each one of us is different. As hobbyists, this is especially true, and completely evident when one considers the wide variety of approaches we take to creating and managing our aquariums.

And, fish geeks being fish geeks, we all have our little idiosyncrasies and quirks. I know that I have some that get to me.

Like, a desire to make radical changes, seemingly out of the blue. Now, sure, I am the guy who gives a lot of his tanks and ideas plenty of time and space to "breathe" and develop over time. I'm pretty patient when it come to letting my tanks evolve. 

However, I admit- I DO like to change stuff up sometimes.

Ever wake up one morning  and...it just..hits you? That urge to change up your aquarium; it's look, "theme"- whatever?

Yeah. 

I don't think that it's just a "me" thing, either.

It's part of being a fish geek, I think. 

We look at our existing aquarium and say, "I really love it, but...."

We reach for some towels, grab a bucket, and it's on!

I think it's part of the mental makeup- the fabric, if you will- of the fish geek.

We're sort of almost "programmed" to want to switch stuff up after a while, right? It's like we want to create, modify, renew...or just try something different. 

For many hobbyists, their one aquarium is the only one they can have- at least for now, but possibly forever. Space, economics, time, etc, all come into play, and there really isn't much you can do except work with the one you've got. I mean, it's a blessing to have even one...but to the serious fish geek, that desire to move on to a greener pasture (or should we say, "bluer river?")-to just taste some new stuff- seldom retreats.

Can you relate?  

I think- think- that it's often augmented by my desire as the Tannin "mothership" and a need to continuously showcase new ideas and botanicals. Well, maybe that's an excuse.

But hey, we all love to try new stuff, right?

I know that I do.

And it's funny, because I think that even though I fancy myself as this restless "conceptual" guy who is constantly evolving his ideas, the reality is that my "makeovers" are seldom that radical- rather, their little iterations that represent incremental changes or improvements over previous designs.

I tend to "stay in my lane", and not stray all that far from it.

I almost envy those of you who can make radical changes at the spur of the moment without regret or a whole lot of consideration.

I often wonder why I play with such a tight set of characteristics- you know, certain wood arrangements, use of specific textures, colors, etc. Although I'm definitely prone to "over-analyzing" stuff at times, it's fun now and then to step out of my own mind and look at stuff as if I'm a "third party" of sorts.

Maybe I have that sort of "comfort zone" that I tend not to push myself out too far from. I mean, I operate in a pretty radical "sector" already- the blackwater, botanical-style world. It's not everyone's cup of tea, being pretty different from the conventional, "clear water" aquariums we all know so well. I realized a long term ago that, when I make changes to my tanks, they're almost always more like "iterations" of the existing concept.

Yeah, the "next steps" are often subtle in nature. 

And I think that it's sort of "baked into" the idea of botanical-style aquariums: We set the stage for what nature does. Rather than trying to create a "finished product", I think those who operate in our arena tend to set the stage and let Nature do the rest of the work over time. 

Interestingly, you can still make seemingly dramatic changes to your aquariums, and yet leave considerable parts of them intact and functional. This works great with botanical-style aquariums.

Nature does this all the time.

The idea of leaving the substrate and leaf litter/botanical "bed" intact as you "remodel" isn't exactly a crazy one. And conceptually, it's sort of replicates what occurs in Nature! Materials accumulate on top of other materials, facilitating new biological growth, continued foraging for resident fishes, and a more or less uninterrupted ecology.

Yeah, think about this for just a second.

As we almost constantly discuss, habitats like flooded forests (Igapo and Varzea), meadows, vernal pools, igarape, and swollen streams, which tend to encompass terrestrial habitats, or go through phases where they are terrestrial habitats- for a good part of the year.

In these wild habitats, the leaves, branches, soils, and other botanical materials remain in place, or are added to by dynamic, seasonal processes. For the most part, the soil, branches, and a fair amount of the more "durable" seed pods and such remain present during both phases.

The biggest "disruption" in these habitats is often the transformation from terrestrial to aquatic. However, the "hardscape" (to borrow an aquarium term) largely remains intact.

Sure, a "makeover" of an aquarium can be a seriously disruptive event (for both YOU and your fishes!).

On the other hand, if you take the mindset that this is a "transformation" of sorts, and act accordingly, it becomes more of an evolutionary process. This is something I've done for many years- like a lot of you have, and it not only makes your life a bit easier- it can create pretty good outcomes for the fishes we keep.

The "Urban Igapo" idea that I've been touting for a good part of the past 3 years is a very deliberate execution of this "iterative process", and it's taught me quite a bit about how these habitats function in Nature, and what kinds of benefits they bring to the aquarium.

We've talked about the idea of "flooding" an aquarium setup designed to replicate an Amazonian forest before. You know, sort of attempting to simulate some of the processes which happen seasonally in Nature. With the technology, materials, and information available to us today, the capability of creating a true "year-round" habitat simulation in the confines of an aquarium/vivarium setup has never been more attainable.

Letting go...

So, you have this idea for an aquarium.

You kind of see it in your head...you've assembled the materials, got it sort of together.

You add water.

Then, you walk in the room one day, look at it and- you just HATE it.

Like, you're done with it.  Like, no re-hab on the design. No "tweaking" of the wood or whatever...You're just over the fucking thing. Ever felt that?

What do you do? 

Well, I had this idea for a nano tank a while back. It seemed good in my head...I had it up for a nanosecond.

Even memorialized it with some Instagram Stories posts. Doing that is almost always the sort of thing that forces me to move on something...I mean, if you lay down a public "marker", you've got to go, right?

I thought that the tank would be a sort of "blank canvas" for an idea I had...I liked the idea, in principle.

But I didn't see a way forward with this one. I even took the extraordinary step of removing one element of the tank (the wood) altogether, in the hope of perhaps pivoting and just doing my "leaf only scape V3.0"- but I wasn't feeling it.

Nope.

A stillborn idea. A tank not capable of evolving to anything that interested me at this time.

So...I let it go.

Yeah, made away with it. Shut it down. Terminated it...

Whatever you want to call it.

That's really a kind of extraordinary step for me. I mean, I'm sort of the eternal optimist. I try to make almost everything work if I can...

I mean, some of my favorite tanks evolved out of this mindset of sticking with something...We'll come back to that in bit.

Not this time, however.

I killed it.

Now, in the hours after the aborted aquarium move, I was actually able to gain some clarity about why I did it.

What made me do it? 

I almost always do a sort of "post mortem" analysis when I abort on an idea, and this time was no different. It was pretty obvious to me...the "writing was on the wall" with this one!

I think it centered around two things that I simply can't handle in aquariums anymore.

Don't laugh:

1) I absolutely can't stand aquariums which don't have some sort of background- be it opaque window tint, photo paper, or paint. This tank had no background. You could see the window behind it, and the trees outside on the street, and...yeah. 

2) I disdain seeing filters or other equipment in my aquariums. Like, I hate it more than you can ever even imagine. With really few exceptions,  I simply hate seeing filters and stuff. It's only in recent years that I've been able to tolerate seeing filter returns in my all-in-one tanks...and just barely. Now, this nano had a little hang-on-the-back outside power filter...Which I not only saw from the top, but from behind...because-you got it- I didn't have a goddam background on the tank, yes.

I mean, am I that much of a primadonna that I can't handle that? I mean, maybe, but I like to think of it as a situation where I have simply developed an aesthetic sense that just can't tolerate some stuff anymore. I have good ideas, and then I get to equipment...and it sort of "stifles" them a bit.

This is weird.

Okay, yeah, maybe I am prima donna.

What could I have done to salvage this tank? Add a background?

Use a canister filter and glassware, you say?  

Oh, sure. That's easy, right? I mean, all you see in the tank are these elegant curves of "lily pipes" and intakes...Maybe a surface skimmer...You just take 'em out and bleach 'em every once in a while and they stay nice and clean, and..

Okay, yeah. Great. On paper, anyways.

IMHO, glassware isn't the "organic art" that everyone seems to place on some lofty pedestal in the hobby. It reminds me of high school chemistry lab (which I think I got a C minus in, so some residual trauma there, no doubt). You think it's beautiful...I think it's simply dreadful.

It's another piece of equipment, which you see on the outside of the tank, too, with its "umbilical" of return lines shooting up along the sides. Now sure, I know these were developed to make an obvious, visible necessity (filter returns) more elegant and beautiful...However, to me, they're just that- obvious, visible, distracting...and ugly.

Hell, I've even made crazy efforts to hide the canister filters beneath my tanks before, when I couldn't hide them within the tank. It's like, I had to do something! 

I know, I'm being waaaaay too stupid about this. 

Because, really, with a lot of my reef aquarium work, and for that matter, some of my fave botanical-style tanks, you can see some of this stuff. When you see my next reef tank, you might see couple of submersible pumps in the tank , low and deep behind the rock work.

Yeah.

For some reason, it doesn't completely fry my brain in every single situation. I suppose it's a hypocritical thing, but man, sometimes it freaks me out and sometimes I can give it a pass. 

Weird, huh?

Like, why do some tanks get a pass, and others just freak me out with this stuff.

I think, maybe, it's about the "concept"of the tank.  Or the context. Like, some of my fave ever tanks, like my leaf-litter-only tanks, typically will have some equipment evident, because they are essentially a "zero-releaf" aquascape, with nothing that you can hide this stuff behind, like wood or rocks, or whatever. It's as "honest" as it gets. If you want to filter and heat the tank, you only have few options.

It never bothered me all that much in those types of tanks.

Yet, in other tanks? Just fugettaboutit!

Yeah, it MUST be about the concept of the tank. Not only will I forgive the visible equipment, sometimes I'll forgive myself the entire poor execution, too. Because, when I look back at some of the stuff I've done, that was definitely the mindset. Like, I was just happy to sort of pull it off, despite how crappy it looked, as this little gem from 2004 graphically illustrates:

Now that I look back on it, there were actually tons of times when I just let a tank evolve, unmolested and unhurried, because something spoke to me...no matter how weird or seemingly dumb the concept may have initially appeared. There was something about it that I believed in...

And occasionally, I'll try something, tear it down, and just regret it. Like, I'll realize, too late, that there was something I liked about the idea, and that I should have kept at it; let it do it's thing.

Like, what IF I kept it in play for little longer?

I mean, could it have evolved into something cool?

Maybe.

I recall a particular experiment I did with Spider Wood, which I let go very early in the game. The arrangement was almost a "reef like" concept...It didn't look right at the time, so I killed it way too early.

Like, a few tweaks to the wood stack, a buildup of substrate in the back of it, a buildup of some leaves and maybe some plants in the back, and it could have been a respectable recreation of the banks of some of the forest floor streams that I've seen in South America.

Yeah, I'd love to try that one again.

Then there were others which I had great faith in right from the start. Even though they looked a bit weird initially, I knew that they'd evolve into something special if I let them be.

Some just hit  the right note, despite a possibly shaky start. Just knew that the idea was so special, that given the space and time, they'd eventually hit the right notes...And they did.

And, then, there were those ideas which, despite their unconventional appearance, were iconic to me, because they represented the culmination of although experiment; a transformation from research to idea to reality. Stuff which created a real transformation in the way I look at aquariums. The "Urban Igapo" style aquairums that many of us execute now, arose from just such an idea.

Sometimes, you just know it. You just feel that letting go of your preconceptions, doubts, and fears, rather than letting go of the tank-is just the right move.

Regardless of the idea, or the appearance of your tank, if there is any way to salvage what you feel is a great idea- even if it means just waiting it out for awhile-  do it. 

You just never know if that one "not so good"idea will turn out to be the one that changes everything for you, and inspires others in the process. Your "fail" might be the unlock- the key- for someone else who was about give up, and then suddenly saw something in your work, and created a tank based on your "failed" concept- executed on an idea-which truly touched others in ways you might not have even thought of.

So, yeah- let go...in the right way.

Stay bold. Stay patient. Stay creative. Stay optimistic. Stay enthusiastic. Stay persistent...

And Stay Wet.

Evolving techniques

It's kind of fun to make little "tweaks" or adjustments to our aquarium methodology or approaches to how we do certain things. This is what pushes the state of the art in aquaristics further down the road. Now, not every one of these adjustments is a quantum leap forward, at least, not initially. Many are simply subtle iterations of things we've played with before.

An example?

One of our fave approaches, sort of derived out of our "Urban Igapo" work, has been to "dry set" the aquarium.  A sort of technique I call the "transitional approach." 

Basically, all you're doing is adding the prepared botanicals and leaves to your aquarium before it's filled, and spraying them down with water and our sprayable Purple Non-Sulphur bacterial inoculant, "Nurture" to kick-start the biological processes. Let it sit. Spray it down daily.

Then fill it.

Unlike in our "Urban Igapo" approach, you're not trying to grow terrestrial grasses or plants during the "dry phase." You're simply creating and managing  what will ultimately be the submerged habitat in your aquarium for a while before filling it.

I've done this a number of times and had great results.

Stupidly simple. Yet, profoundly different.

Why?

Because, rather than our "traditional" approach of adding the botanicals and leaves to the aquarium after it's already filled, you're sort of replicating what happens in Nature in the wild when forest floors and other terrestrial environments are inundated by overflowing streams and rivers.

The thing I like about this approach (besides how it replicates what happens in the wild) is that it gives you the ability to really saturate and soften  the botanicals and leaves, and to begin the process of decomposition and bacterial colonization before you add the water. 

When do you fill the aquarium?

You can wait a few days, a week or two, or as long s you'd like, really. The idea is to get the materials physically placed, and to begin the process of colonization and "softening" by fungi and bacterial biofilms- known as "conditioning" by ecologists who study these habitats. 

And of course, fishes and invertebrates which live amongst and feed directly upon the fungi and decomposing leaves and botanicals will contribute to the breakdown of these materials as well! Aquatic fungi can break down the leaf matrix and make the energy available to feeding animals in these habitats. And look at this little gem I found in my research:

"There is evidence that detritivores selectively feed on conditioned leaves, i.e. those previously colonized by fungi (Suberkropp, 1992; Graca, 1993). Fungi can alter the food quality and palatability of leaf detritus, aecting shredder growth rates. Animals that feed on a diet rich in fungi have higher growth rates and fecundity than those fed on poorly colonized leaves. Some shredders prefer to feed on leaves that are colonized by fungi, whereas others consume fungal mycelium selectively..."

"Conditioned" leaves, in this context, are those which have been previously colonized by fungi! They make the energy within the leaves and botanicals more available to higher organisms like fishes and invertebrates! 

We've long maintained that the appearance of biofilms and fungi on your botanicals and wood are to be celebrated- not feared. They represent a burgeoning emergence of life -albeit in one of its lowest and most unpleasant-looking forms- and that's a really big deal. 

"Oh shit, he's going to talk about biofilms AGAIN!"

Well, just for a second.

Biofilms, as we probably all know by now, form when bacteria adhere to surfaces in some form of watery environment and begin to excrete a slimy, gluelike substance, consisting of sugars and other substances, that can stick to all kinds of materials, such as- well- in our case, botanicals. It starts with a few bacteria, taking advantage of the abundant and comfy surface area that leaves, seed pods, and even driftwood offer.

The "early adapters" put out the "welcome mat" for other bacteria by providing more diverse adhesion sites, such as a matrix of sugars that holds the biofilm together. Since some bacteria species are incapable of attaching to a surface on their own, they often anchor themselves to the matrix or directly to their friends who arrived at the party first.

It's a literal explosion of life. It's a gift from Nature. And we can all receive it and benefit from it! 

Another advantage of this approach? The traditional "cycling" time of a new tank seems to go much faster. Almost undetectable, in many of my experiments. I can only hypothesize and assume that it's likely a result of all of the bacterial growth in the "terrestrial" phase, and the concurrent  "conditioning" of the botanical materials.  

Tannin's creative Director, Johnny Ciotti, calls this period of time when the biofilms emerge, and your tank starts coming alive "The Bloom"- a most appropriate term, and one that conjures up a beautiful image of Nature unfolding in our aquariums- your miniature aquatic ecosystem blossoming before your very eyes!

The real positive takeaway here: Biofilms are really a sign that things are working right in your aquarium! A visual indicator that natural processes are at work, helping forge your tank's ecosystem.

So, what about the botanicals?

The idea of utilizing botanicals in the aquarium can be whatever you want, sure. However, if you ask me (and you likely didn't)- the idea of utilizing these materials in our tanks has always been to create unique environmental conditions and foster a biome of organisms which work together to form a closed microcosm. That is incredible to me.

And the idea of "dry setting" your botanical materials and sort of "conditioning" them before adding the water, this "transitional approach", while not exactly some "revolutionary" thing, IS an evolutionary step in the development of botanical-style aquarium keeping.

The "transitional approach" is definitely a bit different than what we've done in the past, and may create a more stable, more biologically diverse aquarium, because you're already fostering a biome of organisms which will make the transition to the  aquatic habitat and "do their thing" that much more quickly.

This IS unique.

We're talking about actually allowing some of the decomposition to start before water is ever added to our tanks. It's a functional approach, requiring understanding, research, and patience to execute. There's really nothing difficult about it.

And the aesthetics? They're going to be different than what you're used to, no doubt. They will follow as a result of the process, and will resemble, on a surprisingly realistic level, what you see in Nature.

But the primary reason is NOT for aesthetics... 

The interactions and interdependencies between terrestrial and aquatic habitats are manifold, beneficial, and quite compelling to us as hobbyists. To be able to study this dynamic first hand, and to approach it somewhat methodically, is a significant change in our technique.

And yeah, it's almost absurdly easy to do.

The hard part is that it requires a bit more patience; not everyone will see the advantages, or value, and the trade-off between waiting to fill your tank and filling it immediately. It may not be one that some are willing to make.

If you do, however, you will get to see, firsthand, the fascinating dynamic between the aquatic and the terrestrial environment in a most intimate way.

It could change your thinking about how we set up aquariums. 

It could.

At the most superficial level, it's an acknowledgement that, after many decades, we as hobbyists are acknowledging and embracing this terrestrial-aquatic dynamic. It's a really unique approach, because it definitely goes against the typical "aquatic only" approach that we are used to.

When you consider that many aquatic habitats start out as terrestrial ones, and accumulate botanical materials and provide colonization points for various life forms, and facilitate biological processes like nutrient export and production of natural food resources, the benefits are pretty obvious. Again, the "different aesthetics" simply come along as "part of the package"- both in Nature and in the aquarium.

Replicating this process and managing it in the aquarium also provides us as hobbyists highly unique insights into the function of these habitats. 

From a hobby perspective, evolving and managing a closed ecosystem is really something that we should take to easily.

Setting up an aquarium in this fashion also provides us with the opportunity to literally "operate" our botanical-style aquariums; that is, to manage their evolution over time through deliberate steps and practices is not entirely unknown to us as aquarium hobbyists.

It's not at all unlike what we do with planted aquarium or reef aquarium. In fact, the closest analog to this approach is the so-called "dry start" approach to planted aquariums, except we're trying to grow bacteria and other organisms instead of plants.

Yes, it's an evolution.

Simply, a step forward out of the artificially-induced restraints of "this is how it's always been done"- even in our own "methodology"- yet another exploration into what the natural environment is REALLY like, how it evolves, and how it works- and understanding, embracing and appreciating its aesthetics, functionality, and richness.  

Earth-shattering? Not likely.

Educational? For sure.

Thought provoking and fun? Absolutely.

A simple, yet I think profound "tweak" to our approach.

Stay curious. Stay open-minded. Stay thoughtful. Stay observant. Stay creative.

And Stay Wet.

Scott Fellman

Tannin Aquatics 

Transitional Habitats...A new aquarium hobby frontier?

We've spent a lot of time over the least several years talking about the idea of recreating specialized aquatic systems. We've talked a lot about transitional habitats- ecosystems which alternate between terrestrial and aquatic at various times of the year.  These are compelling ecosystems which push the very limits of conventional aquarium practice. 

As you know, we take a "function first" approach, in which the aesthetics become a "collateral benefit" of the function. Perhaps the best way to replicate these natural aquatic systems inner aquariums is to replicate the factors which facilitate their function. So, for example, let's look at our fave habitats, the flooded forests of Amazonia or the grasslands of The Pantanal.

To create a system that truly embraces this idea in both form and function, you'd start the system as a terrestrial habitat. In other words, rather than setting up an "aquarium" habitat right from the start, you'd be setting up what amounts to a terrarium. Soil/sand, terrestrial plants and grasses, leaves, seed pods, and "fallen trees/branches" on the "forest floor."

You'd run this system as a terrestrial display for some extended period of time- perhaps several weeks or even months, if you can handle it- and then you'd "flood" the terrestrial habitat, turning it into an aquatic one. Now, I'm not talking about one of our "Urban Igapo" nano-sized tanks here- I"m talking about a full-sized aquarium this time.  

This is different in both scale and dynamic. After the "inundation", it's likely that many of the plants and grasses will either go dormant or simply die, adding other nutrient load in the aquarium.

A microbiome of organisms which can live in the aquatic environment needs to arise to process the high level of nutrients in the aquarium. Some terrestrial organisms (perhaps you were keeping frogs?) need to be removed and re-housed.

The very process of creating and populating the system during this transitional phase from terrestrial to aquatic is a complex, fascinating, and not entirely well-understood one, at least in the aquarium hobby. In fact, it's essentially a virtually unknown one. We simply haven't created all that many systems which evolve from terrestrial to aquatic.

Sure, we've created terrariums, paludariums, etc. We've seen plenty of "seasonally flooded forest" aquairums in biotope aquarium contests...But this is different. Rather than capturing a "moment in time", recreating the aquatic environment after the inundation, we're talking about recreating the process of transformation from one habitat to another.

Literally, creating the aquatic environment from a terrestrial one.

Psychologically, it would be sort of  challenging!

I mean, in this instance, you've been essentially running a "garden" for several months, enjoying it and meeting the challenges which arise, only to embark several months later on a process which essentially destroys what you've created, forcing you to start anew with an entirely different environment, and contend with all of its associated challenges (the nitrogen cycle, nutrient control, etc.)

Modeling the process. 

Personally, I find this type of approach irresistible. Not only do you get to enjoy all sorts of different aspects of Nature- you get to learn some new stuff, acquire new skills, and make observations on processes that, although common in Nature, were previously unrecorded in the aquarium hobby. 

You'll draw on all of your aquarium-related skills to manage this transformation. You'll deal with a  completely different aesthetic- I mean, flooding an established, planted terrestrial habitat filled with soils and plants will create a turbid, no doubt chaotic-looking aquascape, at least initially. 

This is absolutely analogous to what we see in Nature, by the way.Seasonal transformations are hardly neat and tidy affairs. 

Yes, we place function over form. However, that doesn't mean that you can't make it pretty! One key to making this interesting from an aesthetic perspective is to create a hardscape of wood, rocks, seed pods, etc. during the terrestrial phase that will please you when it’s submerged.

You'll need to observe very carefully. You'll need to be tolerant of stuff like turbidity, biofilms, algae, decomposition- many of the "skills"we've developed as botanical-style aquarists.You need to accept that what you're seeing in front of you today will not be the way it will look in 4 months, or even 4 weeks.

You'll need incredible patience, along with flexibility and an "even keel.”

We have a lot of the "chops" we'll need for this approach already! They simply need to be applied and coupled with an eagerness to try something new, and to help pioneer and create the “methodology”, and with the understanding that things may not always go exactly like we expect they should.

For me, this would likely be a "one way trip", going from terrestrial to aquatic. Of course, much like we've done with our "Urban Igapo" approach, this could be a terrestrial==>aquatic==>terrestrial "round trip" if you want! That's the beauty of this. You could do a complete 365 day dynamic, matching the actual wet season/dry season cycles of the habitat you're modeling.

Absolutely. 

The beauty is that, even within our approach to "transformational biotope-inspired" functional ecosystems, you CAN take some "artistic liberties" and do YOU. I mean, at the end of the day, it's a hobby, not a PhD thesis project, right?

Yeah. Plenty of room for creativity, even when pushing the state of the art of the hobby! Plenty of ways to interpret what we see in these unique ecosystems.

Habitats which transition from terrestrial to aquatic require us to consider the entire relationship between land and water- something that we have paid scant little attention to in the aquarium hobby, IMHO. 

And this is unfortunate, because the relationships and interdependencies between aquatic habitats and their terrestrial surroundings are fundamental to our understanding of how they evolve and function.

There are so many other ecosystems which can be modeled with this approach! Floodplain lakes, streams, swamps, mud holes...I could go on and on and on. The inspiration for progressive aquariums is only limited to the many hundreds of thousands of examples which Nature Herself has created all over the planet.

We should look at nature for all of the little details it offers. We should question why things look the way they do, and postulate on what processes led to a habitat looking and functioning the way it does- and why/how fishes came to inhabit it and thrive within it.

With more and more attention being paid the overall environments from which our fishes come-not just the water, but the surrounding areas of the habitat, we as hobbyists will be able to call even more attention to the need to learn about and protect them when we create aquariums based on more specific habitats.

The old adage about "we protect what we love" is definitely true here!

And the transitional aquatic habitats are a terrific "entry point"into this exciting new area of aquarium hobby work.

Stay inspired. Stay creative. Stay observant. Stay resourceful. Stay diligent...

And Stay Wet.

Scott Fellman

Tannin Aquatics 

Keeping it together: The beauty of "buttress roots" and their function in the flooded forests...

There is something incredibly compelling about the way terrestrial trees and shrubs interact with the aquatic environment. This is a surprisingly dynamic, highly inter-dependent relationship which has rarely been discussed in aquarium circles.

Let's have that talk!

We have talked a lot about roots before...They are structures which are so important in so many ways to these ecosystems, in both their terrestrial and aquatic phases.

Not only do they help "secure the soils" from falling away, they foster epiphytic algae, fungal growth, and biofilms, which supplement the foods of the resident fishes. And of course, they provide a physical habitat for fishes to forage, seek shelter, and reproduce among. In short, these roots create a unique "microhabitat" which harbors a diversity of life.

And they look pretty aesthetically cool, too!

So yeah- this makes them an irresistible subject for a natural-looking- and functioning- aquascape!. And relatively easy to execute, too!

With a variety of interesting natural materials readily available to us as hobbyists, it's easier than ever to recreate these habitats in as detailed a version as you care to do. 

As usual with my ramblings, this blog has become yet another homage to roots and other forest features, and how they function in the transitional aquatic habitats we love so much.

One of the foundational root types that we can replicate in or aquarium works what botanists call "buttress roots." Not only are these interesting structures to replicate in our aquariums, they are an important component of the ecosystems which make up the flooded forests, particularly in areas like Amazonia.

Buttress roots are large, very wide roots that help keep shallow-rooted forest trees from toppling over. They are commonly associated with nutrient-poor soils (you know, like the kinds you see in the igapo or varzea ecosytems). These roots also serve to take uptake nutrients are available in these podzolic soils.

The buttress roots of various species of forest trees often weave in and out of each other horizontally, and create a vast network which serves to keep many trees in the forest from toppling over. And since these habitats often flood during the rainy season, buttress roots help stabilize the trees and retain soils during this inundation.

Isn't that interesting? Even the trees have made adaptations over eons which allow them to survive under these harsh conditions! As you might suspect, the "white-water" flooded forests (Varzea) tend to be richer in species diversity and density than the less nutrient-dense blackwater-flooded Igapo forests. Seems like everything in these ecosystems is a function of nutrient availability, isn't it?

However, the use of larger pieces of wood- or several pieces of wood aggregated together- can create really interesting structures which can replicate the form and function of buttress roots in the aquarium. 

At the very least, you can try a fairly large piece of aquatic wood (or several smaller pieces, aggregated to form one large piece) some time. I think you might find this sort of arrangement quite fascinating to play with!

Arrange the wood in such a way as to break up the tank space and give the impression that it simply rooted naturally. Let it create barriers for fishes to swim into, and disrupt water flow patterns. Allow it to "cultivate" fungal growth and biofilms on its surfaces, and small pockets where leaves, botanicals, substrate materials, and...detritus can collect.

This is exactly what happens in Nature.

It's fascinating and important for us to understand- at least on a superficial level- the concept of replicating some of the structures and features of these transitional habitats, such as flooded forest floors.

By understanding how these structures work, why the exist, and how they provide a benefit to the organisms which live among them, we will be in an excellent position to incorporate exciting features- such as buttress roots-into our future aquariums!

Stay inspired. Stay educated. Stay bold. Stay creative. Stay thoughtful...

And Stay Wet.

Scott Fellman

Tannin Aquatics 

New start. New approach.

One of the best things about not having a lot of tanks in operation at the moment (Wait, let's correct that...the ONLY good thing about not having a lot of tanks in operation at the moment...😆) is that it gives you the opportunity to plan, review, and plot your next moves. 

I'm in such a phase at home, with my house undergoing a substantial remodel and all of my "full-size" tanks in storage for a couple more months. As I've told you previously, it's given me the opportunity to play with a lot of ideas quickly in "nano-sized" aquariums. 

And of course, I've thought s lot about how I'm going to start up my next botanical-style tanks.

Here's an approach I'm trying on one of them. I call it the "transitional" approach.

Okay, we've tackled our "Urban Igapo" idea a bunch of times here, with the technique being described and studied quite a bit. Now, the repetition of wet and dry "seasonal cycles" in the aquarium, although fascinating and the most novel takeaway from this approach, is but one way to apply the idea of evolving a "dry forest floor" into an aquatic habitat.

This is one of the most incredible and fascinating ecological dynamics in Nature, and it's something that we as a hobby have not attempted to model to any extent, until we started messing around with the idea of replicating it around 2017. Again, we're not talking about replicating the 'look" of a flooded forest after it's been flooded...That has been done for years by hobbyists, particularly in biotope design contests. An "aquascaping" thing. 

This is a bit different. 

We're talking about actually replicating and flooding the damn forest floor! Replicating the cycle of inundation. It's a functional approach, requiring understanding, research, and patience to execute. And the aesthetics...They will follow, resembling what you see in Nature. But the primary reason is NOT for aesthetics... 

So, the way this would work is to simply set up the tank like our "standard" approach to creating an "Urban Igapo"- utilizing a sedimented substrate (um, yeah, we make one....) to create a "forest floor." And then, you add leaves, botanicals, and perhaps, some terrestrial grass seeds, and even riparian plants.

You'd set whatever "hardscape" you want- driftwood, etc. in place. Of course, you'd have to water your little forest floor for some period of time, allowing the vegetation to sprout and grow. Based on the many times of played with the "Igapo" idea, this process typically takes around 2-3 months to establish the growth well. 

And then what? Well, you'd flood it!

You could do this all at one time, or over the course of several  days, depending upon your preference. I mean, you've waited a couple of months to add water to your tank...what's another few days? 😆 Now, sure, there's a difference between a 5-gallon tank and a 50- gallon tank, and it takes a lot longer to fill, so it's up to you how you want to approach this!

And what you'd initially end up with is a murky, tinted environment, with little bits of leaves, botanicals, and soil floating about. Sounds like a blast, huh? And when you think about it, this is not all that different, at least procedurally, from the "dry start" approach to a planted tank...except we're not talking about a planted tsmnk here.. I mean, you could do aquatic plants...but it's more of a "wholistic biome" approach...

The interesting thing about this approach is that you will see a tank which "cycles" extremely quickly, in my experience. In fact, Iv'e done many iterations of "Urban Igapo" tanks where there was no detectible "cycle" in the traditional sense. I don't have an explanation for this, except to postulate that the abundance of bacterial and microorganism growth, and other life forms, like fungal growths, etc., powered by the nutrients available to them in the established terrestrial substrate expedites this process dramatically.

That's my theory, of course, and I could be way, way off base, but it is based on my experience and that of others in our community over the past several years. I mean, there is a nitrogen cycle occurring in the dry substrate, so when it's inundated, do the bacteria make the transition, or do they perish, followed by the very rapid colonization by other species, or..?

An underwater biome is created immediately with this approach. Doing this type of "transition" is going to not only create a different sort of underwater biodiversity, it will have the "collateral benefit" of creating a very different aesthetic as well. And yeah, it's an aesthetic that will be dictated by Nature, and will encompass all of those things that we know and love- biofilms, fungal growth, decomposition, etc.

I've done this in aquariums up to 10 gallons so far, with great success, so I'm completely convinced that this process can be "scaled up" easily. The technique is the same. 

Now, one fundamental difference between this approach and the more "traditional" "Urban Igapo" approach is that it's a "one way trip"- start our dry and take it to "wet", without going through repetitive dry cycles. The interesting thing to me about this approach is that you're going to have a very nutrient-rich aquarium habitat, with a big diversity of life from the start.