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 I 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. 

So, once again, let's contemplate what happens in Nature in the "rainy season" in say, the Amazon Basin.


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! Think about THAT for a minute. 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?

Yet another reason why we need to protect these precious habitats. You cut down a tree in the Amazon- you're literally reducing the amount of rain that can be produced.

It's that simple.

That's really important. It's more than just a cool "cocktail party sound bite."

So what happens to the (aquatic) environment in which our fishes live in when it rains? What does the rain actually do?

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, for example- is the evolution of our most compelling environmental niches. The water levels in the rivers rise significantly. often several meters, and the once dry forest floor fills with water from the torrential rain and overflowing rivers and streams.

The Igapos are formed. 

Flooded forest floors.

The formerly terrestrial environment is now transformed into an earthy, twisted, incredibly rich aquatic habitat, which fishes have evolved over eons to live in and utilize for food, protection, and spawning areas.

All of the botanical material-shrubs, grasses, fallen leaves, branches, seed pods, and such, is suddenly submerged; often, currents re-distribute the leaves and seed pods and branches into little pockets and "stands", affecting the (now underwater) "topography" of the landscape.

Leaves begin to accumulate.

Soils dissolve their chemical constituents- tannins, and humic acids- into the water, enriching it. Fungi and micororganisms begin to feed on and break down the materials. Biofilms form, crustaceans multiply rapidly.  Fishes are able to find new food sources; new hiding areas to spawn.

Life flourishes.

So, yeah, the rains have a huge impact on tropical aquatic ecosystems. And it's important to think of the relationship between the terrestrial habitat and the aquatic one when visualizing the possibilities of replicating nature in your aquarium in this context.

It's an intimate, interrelated, "codependent" sort of arrangement!

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 commendable power of restraint.

One of the things that we find ourselves doing in the aquarium hobby is using " a little of this and that" in our tanks, because-well- because we seem to be fixated on lots of variety of "stuff" in our tanks, right?

I mean, there is nothing wrong with using a diversity of materials in our aquariums to express our creativity, and I DO own a company which sells a significant variety of natural aquascaping materials...However, I think it's important to consider exactly what it is we're trying to accomplish in our tanks when we select and employ botanical materials in our aquariums.


As we've discussed a lot around here, the idea of using natural materials, like wood, leaves, seed pods, and roots is a faithful representation of many of the wild habitats we obsess over. And more important, it's a functional methodology of fostering natural processes and a healthy ecology in our tanks.

Are you simply trying to add some aquascaping interest to your tank? Are you interested in manipulating the aquarium water chemistry? Perhaps you're attempting to replicate a very specific ecological niche? Setting up a system for breeding fishes or rearing their fry?

There are many, many applications for botanicals in aquariums. A wide range of things you can do with them, and an even wider range of botanicals to do the job. And the most important "job" for botanicals in our aquariums, IMHO, is to foster the ecology of the aquarium...The so-called "microbiome."

And the important thing to know in this context is that you don't have to use 25 different botanicals and leaves in your aquarium to achieve this ecology within your tank. The reality is that, organisms like fungal growth, bacteria, Paramecium, and other microfauna are typically not tied to a specific leaf or seed pod, so not having a huge variety doesn't mean that you won't be able to achieve a significant microbiome within your tank.

So from a "biodiversity" or ecological standpoint, there is no reason why you would need a huge variety of botanicals in a given aquarium. It really boils down to aesthetics. Or, if you're trying to be more "biotopically accurate"- it depends upon the variety of materials that you'd expect to find in the habitat you're interested in replicating.

For example, a flooded forest might have a lot more ( in both density and variety) leaves and seed pods than say, a fast-flowing river, stream, or a small oxbow lake might have. Other locales might simply have a lot of a few materials, like branches and leaves, but minimal amounts of seed pods and other materials. 

Maybe you're not trying to replicate any specific habitat at all. Perhaps it's simply a creative expression with botanicals. That's fine. You can use as many or as little as you want...and you still get the "functional" aspects if you don't "edit" them!

How your botanical-style aquarium looks and (to a lesser extent, functions) is dependent upon these types of characteristics. Yet, it's really a matter of what works best for the aquarium that you are trying to create. The power of restraint is a very important factor when playing with botanicals!

Now again, with all of the cool botanical materials available to hobbyists here and elsewhere, it's certainly fun to use a large variety of different materials in your tank! I personally have always been of the opinion that too much variety in a given tank is sort of distracting and just somehow doesn't always look good. I mean, it certainly just doesn't always! Somehow, using a little less variety in a given tank seems to just look a bit better, IMHO.

However, as we've mentioned already, if you're replicating a specific habitat that might have a wide variety of materials in a given small locale, it makes sense, right?

And there is the benefit of a field of botanicals not only cultivating microbial and fungal food sources for fishes, there is the direct consumption of the botanicals (or their constituent materials) by fishes.

Yes, direct consumption of botanicals by fishes is something that we haven't talked all that much about over the years here.

It's long been known that many species of fishes, particularly Panaque/Panaqolus and some Hypostomus/Cochliodon love botanical stuff. These species are equipped with teeth specifically "designed" to gouge wood. And there's probably another odd one or two that consume it as well. Now, you should be aware that wood "eaters" don't consume the wood per se, they consume it as a "by-product" of their overall feeding strategy.

(The "business end" of Panaque nigrolineatus by Neale Monks, used under CC BY-SA 3.0)

In fact, some recent scientific studies have corroborated digestive enzyme activity profiles and gastrointestinal fermentation levels in the fishes’ GI tracts, suggesting that the "wood-eating catfishes" are not true xylivores, such as beavers and termites, but rather, are detritivores like so many other fishes from the family Loricariidae.

In fact, the conclusion of one study indicated that "..the fishes’ whole digestive strategy ranging from intake, to passage rate, digestive enzyme activities, gastrointestinal fermentation, and decreasing surface area in the distal intestine suggests that these fishes are geared for the digestion and assimilation of soluble components of their detrital diet.

However, the wood-eating catfishes do take macroscopic detritus (i.e., woody debris) and reduce it to <1 mm in diameter, which likely has significant consequences for carbon cycling in their environment. Given that much of the Amazonian basin is unstudied, and much of it is under threat of deforestation (leading to more wood in waterways), the wood-eating catfishes may play a crucial role in the dynamics of the Amazonian ecosystem, and certainly in the reduction of coarse woody debris."

(German DP. Inside the guts of wood-eating catfishes: can they digest wood? Journal of Comparative Physiology B, Biochemical, Systemic, and Environmental Physiology. 2009;179(8):1011-1023. doi:10.1007/s00360-009-0381-1.)

Interesting, right?

And it has some implication for how we keep these fishes in our botanical-style aquariums, right? I mean, we have no shortage of pics of your Plecos tearing into various botanicals, ranging from leaves to seed pods, like the Calotropis pods, Cariniana pods, etc. So, based on the study above, it would suggest that at least part of the pods do form a part of the diet of these fishes, and in the process of consuming them, the fishes are helping enrich the aquarium habitat. 

Now, the botanicals themselves may not be "the whole meal" for many fishes, but the biofilms, algal threads, and other biocover which grow on them do provide foraging for many fishes. A number of us have noticed a wide-ranging variety of fishes, from Barbs to characin to cichlids, feeding actively on the materials on the materials which are "recruited" by submerged botanicals.

This type of activity has led me to postulate that the use of botanicals can perform a definite "feeding support function" for a wide variety of fishes. So, I suppose, one advantage of a variety of botanical materials in one tank is that it increases your chances of having something palatable to someone in the tank!

If you've followed us for any length of time, you're well aware that we are not just pushing you to play with natural, botanical-style aquariums only for the pretty aesthetics. I mean, yeah, they look awesome, but there is so much more to it than that. We are almost as obsessed with the function of these aquariums and the wild habitats which they attempt to represent!



Understanding why you're choosing to throw botanicals in your aquarium is as important as it is to understand how to employ them. Regardless of how you employ the botanicals, I cannot stress enough the need to go SLOWLY. There is no need to rush and dump everything in at one time, or in huge quantities. Particularly in an established aquarium, where your animals are used to a certain stable range of parameters...It goes without saying that if your introducing materials which can influence water chemistry and quality, you will need to go slow and exercise common sense.

And, since botanicals are actively "breaking down" in your aquarium over their "service lifetimes", it's important to employ good husbandry techniques (i.e.; monitoring of water quality, water changes, regular filter media changes, etc.). Just remind yourself that aquatic botanicals create a "dynamic" environment, and you'll enjoy using them that much more!

Apart from, "What pods should I use for a _____________ style setup?" the most common question we receive is ""Do I leave them in or let them break down in my tank?"

And of course, our simple, likely unsatisfying answer is..."It's your call!"

It's as much about your aesthetic preferences as it is long-term ecological stability of the aquarium. It's a decision that each of us makes based on our tastes, management "style", and how much of a "mental shift" we've made o except the transient nature of a botanical-style aquarium and its function. There really is no "right" or "wrong" answer here. It's all about how much you enjoy what happens  naturally versus what you choose to control in your tank.

I tend to favor Nature. Every time. It's not even close. 

But that's just me.

And of course, we can't ever lose sight of the fact that we're creating and adding to a closed aquatic ecosystem, and that our actions in how we manage our tanks must map to our ambitions, tastes, and the "regulations" that Nature imposes upon us.

Yes, anything that you add into your aquarium that begins to break down is bioload.

Everything that imparts proteins, lignins, tannins, organics, etc. into the water is something that you need to consider. However, it's always been my personal experience and opinion that, in an otherwise well-maintained aquarium, with regular attention to husbandry, stocking, and maintenance, the"burden" of botanicals on your water quality is surprisingly insignificant.

Even in test systems which I intentionally "neglected" by conducting very sporadic water exchanges, once I hit my preferred "population" of botanicals (by building them up gradually), I have never noticed significant phosphate or nitrate increases that could be attributed to their presence.


So, once and for all- is adding a bunch of botanicals to your aquarium "dangerous?"

I mean, it could be, in some instances. Like, adding large quantities of fresh botanicals to an established, stable tank all at once is a recipe for problems. But, this is "Aquarium Keeping 101", right? Like, what would you expect that would happen? Why would you even do that?

It's about common sense.

The reality is, adding botanicals to your tank and using them, replacing them regularly, etc, is no more "dangerous" than anything else we do as aquarists. You simply need to go slowly, apply common sense, follow our prep instructions, and observe your tank carefully.

Look, stuff can still occasionally go wrong, even when you follow instructions and employ common sense. Never lose sight of the fact that aquariums are closed natural ecosystems, and changing the delicate ecological balance within them always risks disrupting established biological processes- and that can have consequences for your fishes.

But, you already KNOW that

It's the reality of Nature, and a reminder that, although we can control some things, Mother Nature calls the shots...

So, the power of "chilling out"- the ability to exercise restraint; to not go crazy adding a ton of stuff all at once- is a huge and very, very important skill for all who play with botanicals to acquire. 

I'll bet that you already have.

Stay creative. Stay curious. Stay excited. Stay restrained...

And Stay Wet.


Scott Fellman

Tannin Aquatics 




What's the big deal about substrates?

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

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

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

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

The substrates are not just "the bottom." 

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

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

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

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

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

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

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

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

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

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

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

Let's think about this for just a second.

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

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

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

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

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


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

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

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


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

True "functional aesthetics!"

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

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

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

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

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

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

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

And of course, I'll tell you once again that immediately inundating a sediment-and-clay-heavy substrate can result in cloudiness. Just like in Nature. And it'll pass after a few days.


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

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

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

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

That's the "big deal" about substrates.

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

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

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

And Stay Wet.


Scott Fellman

Tannin Aquatics 


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


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.

I've been resigned at home to some small, temporary tanks until I complete a major remodeling project, and it's been a real test of my patience working with these makeshift systems until I can once again set up my larger, permanent tanks. And I find that they don't seem to hold my interest as long as the larger tanks do.

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.

These are deliberate, more transformative executions by design.

However, making changes to every existing aquarium does not need to be a super-complicated, highly disruptive thing, right? I’m not advocating 360-degree changes in your aquarium management approach every time something doesn’t give you desired results in 3 days, or every time you're "not feeling it." That's a recipe for chaos

What I am thinking about here is developing the "mental ability" to get yourself easily out of a situation that is simply not working for you- for the benefit of your animals, budget, time- and sanity. Shit, it’s a hobby, so if you’re not enjoying it, what’s the point?

So, maybe it’s not “move fast and break things” for you…perhaps it’s “move at a nice rate of speed and change moderately quickly when things don’t work out.”

What are the benefits of adopting a “move fast” philosophy- or at least the gist of it- for you as an aquarist?

First, you can test a lot of ideas and concepts on your tank relatively quickly, in “real time”, rather than just reading about them on the forums. If you have a general idea of where you want to go with your tank, but are interested in a few approaches, this is not a bad way to go.

You can work in multiple ideas to see if they work, and throw out the ones that don’t, relatively quickly. Now, again, I’m not talking about major hardware shuffles (“Yeah, the 350 was too small, so three weeks later, I broke it down and ordered a 700.” That’s pure insanity). Nope, I’m talking about “tweaks”, like deciding to feed your predatory fishes only at night- or a few days a week…or, perhaps dosing fertilizers only when the display is dark. Changing flow patterns, feeding times, light combinations. "Pulsing" leaf additions...Tweaking.

Not full-scale, drain-the-tank-and-start-from-scratch overhauls. 

Second, you can certainly learn stuff at a more rapid clip, right? If you’re giving yourself the opportunity to “audition” a practice, philosophy, procedure, etc., you can find out if something makes sense a whole lot more than if you commit 1,000 percent to a rigid philosophy of “I’m only going to do it this way.” 

Even if you don’t get the "whole picture" of what’s happening in your tank, attempting quick little experiments can give you an indication of the general direction or trend- an answer to a little piece of the puzzle that you can incorporate to evolve more successfully in the long term.

Finally, this philosophy actually can force you to look at things more "honestly."

In other words, if you decided to do something that maybe you thought might not work- by committing yourself to a “nothing is sacred” attitude at the start of your project, you can evaluate things in a more direct manner, and change things up as necessary to assure overall success of the tank and the health of its inhabitants. If you throw the “fun” part back into the equation, and share your trials and tribulations with other hobbyists, it certainly makes it more enjoyable to stop being stubborn and try to make things work, right? 

Of course, for every action, there’s an equal and opposite reaction, right? So, what are the downsides to a rapid-iteration, “move fast and break things” philosophy?

To  begin with, you will probably build some “mental debt.” In other words, as you rapidly make changes and move things along, you may tend to overlook other things. Human nature, right? You tend to look at every change or iteration as a big experiment, and that you can “fix stuff later”- a kind of dangerous trap to fall into, especially when you think of the potential impact on living organisms.

It’s one thing to make intelligent, measured changes, but to take shortcuts, non-sustainable work-arounds, and “band aids” harbors potential hidden dangers. Be alert to this. Your “pursuit of perfection” could result, ironically, in you never quite getting it right?

In addition, you might find yourself “burnt out” rather quickly. I mean, if you’re chaotically trying every new idea, every new gadget that’s out there in trying to find quick solutions, you will not likely enjoy this hobby for very long. It’s a marathon, not a sprint, right? I mean, it’s a “hobby” at the end of the day. Yet, each day I read forum posts from dozens of hobbyists who flail helplessly in multiple directions, trying every little thing to "change-up" their tank, in a desperate attempt to solve a relatively simple problem.

Algae issues are notorious for soliciting this kind of behavior- the desire to get the problem “solved” has resulted in many disasters (like using all sorts of chemicals and medications to eradicate algae, when the reality is that it could have been eradicated or managed with husbandry tweaks to begin with…). Some of these "fixes" result in a destroyed biome and dead fishes.

Think before you forge ahead with potentially long-term detrimental "fixes."

So, in summary. Changing stuff up- even relatively rapidly- isn't a bad thing, if it's done for the right reasons. Maybe it's "Aquatic A.D.D." or something (I have this theory, lol), but I think it can actually be a good thing. I even think I understand why some people change up their tanks so often.

With me, I suppose I could rationalize occasional bouts of this "fast change syndrome" by telling myself that it's a matter of wanting to try a lot of concepts out which get's me moving. The desire to move into different directions, despite having limited resources of space, time, or money.


Better to let the full range of your imagination inspire and guide you, instead of limit you. That's why I treasure thinking outside the box so much. Not because it's cool to just do things differently "because." Rather, it's because it's really important to follow up on some of those thoughts and ideas we have. Every single one has the potential to lead to some breakthrough or advancement in the hobby.

Use the relentless flow of ideas- and your ability to execute and accept change- to your advantage.

Every single one has potential.

Don't downplay those ideas that pop into your head from time to time, even if it means changing some stuff up. And they don't always have to be super well thought-out ideas, either. 

Sometimes, you can play a "hunch", a "feeling", or a "whim"-and come up with something great.

Can't you think of at least a few things that you tried on a whim, only to realize later that they were incredible efforts that brought you so much joy?

I'll bet that you can.

Execute each one in it's own time. Let them breathe. Develop them. Or squash them quickly. 

But do try them.

Because it's far better to do something than to just think about it, IMHO.

Consistency is important. 

However, change can be good. Really good.

Stay dedicated. Stay focused. Stay reflective. Stay happy...

And Stay Wet.


Scott Fellman

Tannin Aquatics



One of the toughest things in the aquarium hobby is to face the possibility of losing fishes. When you think about it, the idea of keeping live tropical fishes in an aquarium is pretty incredible to begin with. What we take on isn't necessarily "difficult" in many instances. The techniques have been known and shared in the hobby for generations. However, the awesome thing is that we are able to obtain and maintain these organisms in the first place, right? 

And when you add into the equation that are completely responsible for creating essentially the entire environment in which they reside, it becomes even more incredible, right? What we do is pretty special.

However, unlike keeping many other animals as"pets", like dogs, cats, hamsters, rabbits, etc., we have the unique ability to create representations- functional and aesthetic-of the natural habitats from which they come. We can do all sorts of environmental manipulations, and embrace all sorts of evolutions within their aquariums to represent aspects of their natural habitats.


And this ability brings with it a lot of opportunity to innovate, as well as the assumption of some risk.

Yeah, the process of creating, optimizing and managing a specialized aquatic habitat is subject to risk, whether we expect it or not. 


The risk that we might not have acclimated our fishes correctly to the new environment that we have created. Risk that our management of the environment may not be be as controlled, consistent, or appropriate for the long-term health of the fishes.

This is not unique to the botanical-style aquarium, of course. It's something that we run into with all types of aquariums and fish-keeping endeavors, from the most basic goldfish bowl (arrghh!😂) to the most sophisticated reef aquarium system.

Risk permeates this hobby. It's something that is almost never discussed, but it is at the forefront of almost everything do. Risk abounds. We take risks every single time we purchase fish. And the responsibility to manage the risk- to mitigate any potential bad outcomes-lies squarely on our shoulders as hobbyists.

A classic, easy example? When repurchase that new fish, we immediately have to chose whether or not we will quarantine it before placing it into our tank. If we don't, we run the risk of introducing illness to our other healthy fishes. And, when we do quarantine (yay!),we STILL risk the possibility that the fish might not make it through. That it might not eat, or that a disease (the very reason you quarantine in the first place!) may manifest itself and possibly kill the fish in the quarantine system.


When we first started Tannin Aquatics, the idea of utilizing seed pods, bark, leaves, branches and stuff  in aquariums to manipulate the environmental conditions wasn't completely unknown. Hobbyists have been doing it for generations to some extent. However, when we embarked on our mission to curate, test, and ultimately introduce new and different botanical materials into the hobby, we know it was a risk.

Some might have proven to be toxic to fishes. Some might have been collected from polluted environments that had noxious chemicals. Some might have been intended for other purposes, and sold to us by unscrupulous suppliers, who had them treated with laquers or other industrial chemicals. We found this out the hard way a few times, killing fishes in our test tanks in the process.

Horrible to lose innocent animals, but part of the challenge we accepted when we intended to become leaders in this new arena. Releasing untested materials to fellow fish keepers and killing them was not an option. We had to assume the risk of testing ourselves. Vetting of suppliers was, and continues to be, crucial. Good quality source material doesn't guarantee success- but it does mitigate some of the risk. 

When we developed techniques for the preparation of botanicals for aquarium use, it was to help mitigate some of the risks that are inherent when you place natural terrestrial materials into a closed aquatic environment.


Yet, even with the development of "best practices" and recommended approaches and technique for safely utilizing botanicals in our aquariums, we knew that there was an even bigger, more ominous risk out there...Human nature.

Yes, when I started playing with botanicals in my aquariums almost two decades ago, I made a fair number of mistakes. Sometimes, they cost the lives of my fishes.

And killing fishes sucks.


Some mistakes were caused by my lack of familiarity with using various materials. Most were caused by not understanding fully the impact of adding botanical materials to a closed aquatic ecosystems. All were mitigated by taking the time to learn from them and honestly asses the good, the bad, and the practical aspects of using them in our aquariums. 

And that meant developing "best practices" to help mitigate or eliminate issues as much as possible, even though the "practices" may not be the easiest, most convenient, or expedient way to proceed.

I KNEW that there would be people who might kill their fishes by adding lots of botanicals to their established systems without reading and following the instructions concerning preparation, cadence, and what to expect. I knew there would be people who would criticize the idea, "edit" the processes or recommended "best practices", talk negatively about the approach and generally scoff and downplay what they didn't know, understand, or do.

It's human nature whenever you give people something a bit different to play with...They want to go from 0-100 in like one day. And I knew that some of these people would go out on social media and attempt to trash the whole idea after they failed. This, despite all of our instructions, information, and pleas to follow the guidelines we suggested. 

After more than six years of running Tannin, I have pretty much identified the two most common concerns we have for customers associated with utilizing botanicals in their aquariums. Curiously, our two biggest concerns revolve around our own human impatience and mindset- not the botanical materials themselves.

The first is... preparation.

We are often asked why we don't feel that you can, without exception, just give any of your botanicals "a quick rinse" and toss them into your aquarium.

After all, this is what happens in nature, right? Well, shit- yes...but remember, in most cases, there is a significant "dilution factor" caused by larger water volumes, currents, biologically-rich substrates, etc. that you encounter in natural aquatic systems. Even in smaller bodies of water, you have very "mature" nutrient export systems and biological equilibriums established over long periods of time which handle the influx and export of organic materials.  

However, even in Nature, things go awry, and you will occasionally see bodies of water "fouled" by large, sudden influxes of materials (often leaves, grass clippings, etc.)- sometimes after rain or other weather events- and the result is usually polluted water, large algal blooms, and a pretty nasty smell! 

In the aquarium,  of course, you have a closed system with a typically much smaller water volume, limited import of fresh water, limited filtration (export) capacity, and in many cases, a less robust ecological microcosm to handle a large influx of nutrients quickly.

So you know where I'm going with this:

Fresh botanical materials, even relatively "clean" ones, are often still "dirty", from collection, storage, etc. They may have dust, airborne pollutants, soil or silt (depending upon where they were collected), even cobwebs, bird droppings, and dead insects (yuck!).

Natural materials accumulate "stuff." They're not sterile; made in some high tech  "clean room" in a factory in Switzerland, right? 

So," just giving botanicals a quick rinse" before tossing them in your tank is simply not good procedure, IMHO- even for stuff you collect from your own backyard. It's more risk to take on. At the very least, a prolonged (30 to 60 minute) steep in boiling hot water will serve to "sterilize" them to a certain extent. Follow it with a rinse to remove any lingering dirt or other materials trapped in the surfaces of your botanicals.

Now, I don't recommend this process simply because I want to be a pain in the ass. I recommend it because it's a responsible practice that, although seemingly "overkill" in some people's minds- increases the odds for a better outcome.

It reduces some of the risk.

The crew up in the cockpit on your flight from L.A. to New York know every system of the Boeing 737Max9 that they fly. But guess what? They still complete the pre-flight checklist each and every time they hop in the plane.

Because it can save lives.

Why should we be any different about taking the time to prepare botanicals? I know it sounds harsh; however, if you skip this step and kill your fishes- it's on you.


Why would you skip this, other than simply being impatient?

Could you get away with NOT doing this? 

Sure. Absolutely. Many people likely do. 

But for how long? When will it catch up with you? Maybe never...I know I'll get at least one email or comment from a hobbyist who absolutely doesn't do any of this and has a beautiful healthy tank with no problems.

Okay, good for you. I'm still going to recommend that, like I do- that you embrace a preparation process for every botanical item that you add to your aquariums.

Boiling/steeping also serves a secondary, yet equally important purpose: It helps soften and even break down the external tissues of the botanical, allowing it to leach out any remaining subsurface pollutants, sugars, or other undesirable organics to the greatest extent possible. And finally, it allows them to better absorb water, which makes them sink more easily when you place them in your aquarium. 

Yes, it's an extra step.

Yes, it takes time.

However, like all good things in nature and aquariums, taking the time to go the extra mile is never a bad thing. And really, I'm trying to see what possible "benefit" you'd derive by skipping this preparation process?

Oh, let me help you: NONE.


There is simply no advantage to rushing stuff.

Like all things we do in our aquariums, the preparation of materials that we add to them is a process, and Nature sets the pace. The fact that we may recommend 30 minutes or more of boiling is not of concern to Nature. It may take an hour or more to fully saturate your Sterculia Pods before they sink.

So be it.


Savor the process. Enjoy every aspect of the experience.  And don't you love the earthy scent that botanicals exude when you're preparing them?

And the shittiest thing? Even if you do all this prep, there is STILL risk that you will kill your fishes.


Damn, I'm not ever gonna make it as salesman, huh?

How much to use?

Well, that's the million dollar question.

Who knows? Even that is a guess and decidedly unscientific at best! 

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

Now, nothing is perfect.

Nothing we can tell you is an absolute guarantee of perfect results...You're dealing with natural materials, and the results you'll see are governed by natural processes that we can only impact to a certain extent by preparation before use. But it's a logical, responsible process that you need to embrace for long-term success.

It reduces some of the risk.

And, when it comes time to adding your botanicals to your aquarium, the second "tier" of this process is to add them to your aquarium slowly. Like, don't add everything all at once, particularly to an established, stable aquarium. Think of botanicals as "bioload", which requires your bacterial/fungal/microcrusacean population to handle them.

Bacteria, in particular, are your first line of defense.

If you add a large quantity of any organic materials to an established system, you will simply overwhelm the existing beneficial bacterial population in the aquarium, which will likely result in a massive increase in ammonia, nitrite, and organic pollutants. At the very least, it will leave oxygen levels depleted, and fishes gasping at the surface as the bacteria population struggles to catch up to the large influx of materials.

This is not some sort of esoteric concept, right? I mean, we don't add 25 3-inch fishes at once to an established, stable 10-gallon aquarium and not expect some sort of negative environmental consequence, right? So why would adding bunch of leaves, botanicals, wood, or other materials containing organics be any different?

It wouldn't.

So please, PLEASE add botanicals to your established aquarium gradually, while observing your fishes' reactions and testing the water parameters regularly during and after the process. Take measured steps.

There is no rush.

There shouldn't be.

It's interesting how the process of selecting, preparing and adding botanical materials to our aquariums has evolved over the time since we've been in business. Initially, as I discussed previously, it was all about trying to discover what materials weren't "toxic" in some way!

Then, it was about figuring out ways to prepare them and make sure that they don't pollute the aquarium. Finally, it's been about taking the time to add them in a responsible, measured matter.

I think our biggest "struggle" in working with botanicals is a mental one that we have imposed upon ourselves over generations of aquarium keeping:  The need to control our own natural desire to get stuff moving quickly; to hit that "done"

And the reality, as we've talked about hundreds of times here and elsewhere, is that there really is no "finished", and that the botanical-style aquarium is about evolution. This type of system embraces continuous change and requires us to understand the ephemeral nature of botanicals when immersed in water.

I know I may be a bit "blunt" when it comes to these topics of preparation, practices, and patience- but they are critical concepts for us to wrap our heads around and really embrace in order to be successful with this stuff. And they are absolutely tied to the idea of reducing risk to the greatest extent possible.

All caveats and warnings aside, the art and evolving "science" of utilizing natural botanical materials for the purpose of enriching and influencing the environment of the aquarium is an exciting one, promising benefits and breakthroughs that we may not have even thought about yet!

It's okay to experiment...If we are willing to accept the additional risk.

We stress these points over and over an over, because  I get questions every day from hobbyists asking if they really need to prepare their botanicals, and if it's safe to use "_____" in their tanks, etc.

This is indicative, to me, of larger problem in the aquarium hobby.

In a world where people are supposedly not able to retain more than 280 characters of information, and where there is a apparently a "hack" for pretty much everything,  I wonder if have we simply have lost the ability to absorb information on things that are not considered “relevant” to our immediate goal. I say this not in a sarcastic manner, but in a thoughtful, measured one.

I'm baffled by hobbyists who want to try something new and simply do next to no research or self-education prior to trying it.

Like, WTF?

When you read some of the posts on Facebook or other sites, where a hobbyist asks a question which makes it obvious that they failed to grasp even the most fundamental aspects of their "area of interest", yet jumped in head-first into this "new thing", it just makes you wonder!  I mean, if the immediate goal is to have "...a great looking tank with botanicals...", it seems to me that some hobbyists apparently don’t want to take the time to learn the groundwork that it takes to get there and to sustain the system on a long-term basis.

I suppose that it’s far more interesting- and apparently, immediately gratifying- for some hobbyists to learn about what gadgets or products can get us where we want, and what fishes are available to complete the project quickly.

This is a bit of a problem. It demonstrates a fundamental impatience, an unwillingness to learn, and a lack of desire to assume some responsibility or risk. The desire to pass the responsibility on to someone- or something- else when shit goes wrong.

And the reality is that it's really all on us.

When it comes to using botanicals- or, for that matter, embarking upon any aquarium-related speacialties, it's really important to contemplate them from the standpoint of reducing and accepting some risk. We, as aquarium hobbyists, are 100% responsible for the lives of the animals under our care. If we don't like the idea of accepting this responsibility, then we should consider another hobby. Simple as that.

I can talk about the "best practices" in our hobby until my face turns green. I can point out the benefits of making mental shifts and being patient endlessly. However, it's up to each one of us to accept- or reject- these ideas, and to accept the outcomes-positive or negative- of our choices about how we embrace-or reject-this stuff.

And, based on what I'm seeing and hearing, a lot of hobbyists simply don't feel that this applies to them.

Okay, I’m sounding very cynical. And perhaps I am. But the evidence is out there in abundance…and it’s kind of discouraging at times.

Look, I’m not trying to be the self-appointed "guardian of the hobby." I’m not calling us out. I’m simply asking for us to look at this stuff realistically, however. To question our habits. To accept responsibility for our actions. No one has a right to tell anyone that what they are doing is not the right way, but we do have to instill upon the newbie the importance of understanding the basics of our craft.

I'm super-proud that we've consistently elevated realistic discussions about unpopular topics related to our hobby sector. Yeah, we literally have blog and podcast titles like, "How to Avoid Screwing Up Your Tank and Killing all of Your Fishes with Botanicals" , or "There Will be Decomposition", or "Celebrating The Slimy Stuff."

If we are worried about risk, we need to take as many steps as possible to understand it. To mitigate it. Some steps are tedious. Unglamorous. Time consuming. Not very fun.

However, they are all steps that we need take to create better outcomes, and to help advance the state of the art of the aquarium hobby- for the benefit of us all.

Risk is part of the hobby. How we accept it, and take it on, is also part of the hobby. It doesn't have to be a dark cloud hanging over everything that we do. Rather, it should be a motivator, an opportunity to improve, and a means to grow.

Stay responsible. Stay curious. Stay engaged. Stay observant...

And Stay Wet.


Scott Fellman

Tannin Aquatics 







One of the things that drives most hobbyists crazy is when "stuff" gets blown around, covered or moved about in the aquarium. It can be because of strong current, the activity of fishes, or simply overgrown by plants. I understand the annoyance that many hobbyists feel; I recall this same aggravating feeling in many reef tanks where I had high flow and sand on the bottom- almost always a combination for annoyance! 

I mean, I get it. We have what feel is a carefully thought-out aquascape, looking exactly how we expected it would after setup. Yet, despite our ideas and thoughts, stuff moves around in the aquarium. It's something we can either accept, or modify in our aquariums, depending upon our preferences.


Yet, movement and "covering" of various materials by sediments, biofilms, etc., which accumulate on the substrate in natural habitats are everyday occurrences, and they help forge a very dynamic ecosystem. And they are constantly creating new opportunities for the fishes which reside in them to exploit.  

When you think about how materials "get around" in the wild aquatic habitats, there are a few factors which influence both the accumulation and distribution of them. In many topical streams, the water depth and intensity of the flow changes during periods of rain and runoff, creating significant re-distribution of the materials which accumulate on the bottom, such as leaves, branches, seed pods, and the like.

Larger, more "hefty" materials, such as branches, submerged logs, etc., will tend to move less frequently, and in many instances, they'll remain stationary, providing a physical diversion for water as substrate materials accumulate around them.

A "dam", of sorts, if you will.

And this creates known structures within streams in areas like Amazonia, which are known to have existed for many years. Semi-permanent aquatic features within the streams, which influence not only the physical and chemical environment, but the very habits and abundance of the fishes which reside there.

Most of the small stuff, like leaves, tend to move around quite a bit... One might say that the "material changes" created by this movement of materials can have significant implications for fishes. As we've talked about before, they follow the food, often existing in, and subsisting off of what they can find in these areas.

New accumulations of leaves, detritus, and other materials benefit the entire ecosystem.

In the case of our aquariums, this "redistribution" of material can create interesting opportunities to not only switch up the aesthetics of our tanks, but to provide new and unique little physical areas for many of the fishes we keep.

And yeah, the creation of new feeding opportunities for life forms at all levels is a positive which simply cannot be overstated! As hobbyists, we tend to lament changes to the aquascape of our tanks caused by things outside of our control, and consider them to be a huge inconvenience, when in reality, they're not only facsimile of very natural dynamic processes-they are fundamental to their evolution.

The benthic microfauna which our fishes tend to feed on also are affected by this phenomenon, and as mentioned above, the fishes tend to "follow the food", making this a case of the fishes adapting to a changing environment. And perhaps...maybe...the idea of fishes sort of having to constantly adjust to a changing physical environment could be some sort of "trigger", hidden deep in their genetic code, that perhaps stimulates overall health, immunity or spawning?

Something in their "programing" that says, "You're at home..." Perhaps something which triggers specific adaptive behaviors?

I find this possibility fascinating, because we can learn more about our fishes' behaviors, and create really interesting habitats for them simply by adding botanicals to our aquariums and allowing them to "do their own thing"- to break apart as they decompose, move about as we change water or conduct maintenance activities, or add new pieces from time to time.

Again, just like Nature.

We just need to "get over ourselves" on this aesthetic thing!

Another mental shift? Yeah, it is. An easy one, but one that we need make, really.

Like any environment, botanical/ leaf litter beds have their own "rhythm", fostering substantial communities of fishes. The dynamic behind this biotope can best be summarized in this interesting excerpt from an academic paper on blackwater leaf-litter communities by biologist Peter Alan Henderson, that is useful for those of us attempting to replicate these communities in our aquaria:

" within the litter is not a crowded, chaotic scramble for space and food. Each species occupies a sub-region defined by physical variables such as flow and oxygen content, water depth, litter depth and particle size…

...this subtle subdivision of space is the key to understanding the maintenance of diversity. While subdivision of time is also evident with, for example, gymnotids hunting by night and cichlids hunting by day, this is only possible when each species has its space within which to hide.”

In other words, different species inhabit different sections of the leaf litter beds. As aquarists, we should consider this when creating and stocking our botanical-style aquariums.

It  just makes sense, right?


So, when you're attempting to replicate such an environment, consider how the fishes would utilize each of the materials you're working with. For example, leaf litter areas would be an idea shelter for many juvenile fishes, catfishes, and even young cichlids to shelter among.

Submerged branches, larger seed pods and other botanicals provide territory and areas where fishes can forage for macrophytes (algal growths which occur on the surfaces of these materials). Fish selection can be influenced as much by the materials you're using to 'scape the tank as anything else, when you think about it!

And it's not just fishes, of course. It's a multitude of life forms.

There are numerous life forms which are found on ad among these materials as well, such as fungal growths, bacterial biofilms, etc. which we likely never really consider, yet are found in abundance in nature and in the aquarium, and perform vital roles in the function of the aquatic habitat.

Perhaps most fascinating  and rarely discussed in the hobby, are the unique freshwater sponges, from the genus Spongilla. Yes, you heard. Freshwater sponges! These interesting life forms attach themselves to rocks and logs and filter the water for various small aquatic organisms, like bacteria, protozoa, and other minute aquatic life forms. Some are truly incredible looking organisms!

(Spongilla lacustris Image by Kirt Onthank. Used under CC-BY SA 3.0)

Unlike the better-known marine sponges, freshwater sponges are subjected to the more variable environment of rivers and streams, and have adapted a strategy of survival. When conditions deteriorate, the organisms create "buds", known as  "gemmules", which are an asexually reproduced mass of cells capable of developing into a new sponge! The Gemmules remain dormant until environmental conditions permit them to develop once again!

Oh, cool!

To my knowledge, these organisms have never been intentionally collected for aquariums, and I suspect they are a little tricky to transport (despite their adaptability), just ike their marine cousins are. One species, Metania reticulata, is extremely common in the Brazilian Amazon. They are found on rocks, submerged branches, and even tree trunks when these areas are submerged, and remain in a dormant phase in the aforementioned gemmules during periods of desiccation!

Now, I'm not suggesting that we go and collect  freshwater sponges for aquarium use, but I am curious if they occur as "hitchhikers" on driftwood, rocks or other materials which end up in our aquariums. When you think about how important sponges are as natural "filters", one can only wonder how they might perform this beneficial role in the aquarium as well!

We've encountered them in reef tanks for many years...I wonder if they could ultimately find their way into our botanical-style aquariums as well?  Perhaps they already have. Have any of you encountered one before in your tanks?

The big takeaway from all of this: A botanical bed in our aquariums and in Nature is a physical structure, ephemeral though it may be- which functions just like an aggregation of branches, or a reef, rock piles, or other features would in the wild benthic environment, although perhaps even "looser" and more dynamic.

Stuff gets redistributed, covered, and often breaks down over time. Exactly like what happens in Nature.

Think about the possibilities which are out there, under every leaf. Every sunken branch. Every root. Every rock.

It's all brought about by the dynamic process of movement.

Perhaps instead of looking at the movement of stuff in our tanks as an annoyance, we might enjoy it a lot more if we look at it as an opportunity! An opportunity to learn more about the behaviors and life styles of our fishes and their ever-changing environment.

Stay observant. Stay creative. Stay excited. Stay open-minded...

And Stay Wet.


Scott Fellman

Tannin Aquatics 




The slow(er) road to success with fish stocking...

One of the questions which we are asked less and less these days is, 'What kinds of fishes are suitable for a botanical-style aquarium?" I think that after 6 years of pounding all of these ideas into your heads about all of the strange nuances of botanical-style aquariums, it's almost universally understood that pretty much any fishes can live in them.

On the other hand, when it comes to how we stock our tanks, nothing has really changed...however, it could. And it should, IMHO.

We spend a pretty good amount of time studying, scheming, and pondering how to create a compatible, interesting, and attractive community of fishes within our aquariums.

It's probably among the most enjoyable things that we do in the hobby, right?

As a somewhat eccentric philosopher of all things fish, one of my favorite things to ponder is stuff that we do while creating our aquariums which is- intentionally or otherwise- analogous to the factors in Nature that result in the environments and fish populations that we find so compelling.

If you're like me, you likely spend a little too much time pondering all sorts of arcane aspects of the hobby...Okay, so maybe you're NOT like me, but you probably have a rather keen interest in the way Nature operates in the wild aquatic systems of the world, and stock your aquariums accordingly.

As one who studies a lot of details about some of the habitats from which our fishes come, I can't help but occasionally wonder exactly what it is that brings fishes to a given location or niche within a environment?

Now, the first answer we're likely to proffer is the most apparent...right? I mean, they follow the food!

Fishes tend to move into new areas in search suitable food sources as part of their life cycle. And food sources often become available in habitats such as flooded forest areas after the rains come, when decomposing leaves and botanical materials begin to create (or re-activate, as the case may be) "food webs", attracting ever more complex life forms into the area.

When we create our aquariums, we take into consideration a lot of factors, ranging from the temperament and size of our fish selections, to their appearance, right? These are all important factors. However, have you ever considered what the factors are in nature which affect the composition of a fish community in a given habitat?

Like, why "x" fish is living in a particular habitat?

What adaptations has the fish made that make it uniquely suitable for this environmental niche? Further, have you thought about how we as hobbyists replicate, to some extent, the actual selection processes which occur in Nature in our quest to create the perfect community aquarium?

Now, if you're an African Cichlid lover or reef hobbyist, I'm sure you have!

Social hierarchies, spatial orientations, and allopathic processes are vital to success in those types of aquariums; you typically can't get away with just throwing in a random fish or coral and hoping it will just mix perfectly.

However, for many hobbyists who aim to construct simple "community tanks", it isn't that vital to fill specific niches and such...we probably move other factors to the forefront when thinking about possible additions to our community of fishes: Like, how cool the fish looks, how large it grows, if it has a peaceful temperament, etc. More basic stuff.

However, in the end, we almost always make selections based upon factors which we deem important...again, a sort of near-mimicry of natural processes- and how the fishes work in the habitat we've created for them.

"Unnatural selection?" Or...Is it essentially what nature's does for eons?

Oh, and what exactly is an "aquatic habitat", by the way? In short, you could say that an aquatic habitat is the physical, chemical, and biological characteristics which determine the suitability for habitation and reproduction of fishes.

Of course, these characteristics can determine which fishes are found in a given area in the wild- pretty much without exception. It's been happening for eons.

Approaching the stocking of an aquarium by determining which fishes would be appropriate for the physical characteristics of the tank is not exactly groundbreaking stuff.

However, when we evaluate this in the context of "theme", and what fish would be found within, say, an Amazonian Igarape stream or a Southeast Asian peat swamp, the idea of adding fishes to "exploit" the features of the habitat we've created is remarkably similar to the processes which occur in Nature that determine what fish are found there, and it's the ultimate expression of good tank planning, IMHO.

It's just kind of interesting to think about in that context, right?

Competition is another one of the important factors in determining  how fish populations in the wild. Specifically, competition for space, resources (e.g.; food) and mates are prevalent. In our aquariums, we do see this to some extent, right? The "alpha male" cichlid, the Pleco that gets the best cave, and the Tetra which dominates his shoal.

How we create the physical space for our fishes can have significant impact on this behavior. When good hiding spaces are at a premium, as are available spawning partners, their will be some form of social hierarchy, right?

Other environmental factors, such as  water movement, dissolved oxygen, etc. are perhaps less impactful on our community once the tank is established. However, these factors figure prominently in our decisions about the composition of, or numbers or fishes in the community, don't they?

For example, you're unlikely to keep Hillstream loaches in a near stagnant, blackwater swamp biotope aquarium, just like you'd be unlikely to keep Altum Angelfish in a fast-moving stream biotope representation. And fishes which shoal or school will, obviously, best be kept in numbers.

"Aquarium Keeping 101", again.

One factor that we typically don't have in our aquaria is predation. I know very few aquarists who would be sadistic enough to even contemplate trying to keep predators and prey in the same tank, to let them "have at it" and see what happens, and who comes out on top!

I mean, there is a lot to this stuff, isn't there?

Again, the idea of creating a tank to serve the needs of certain fishes isn't earth-shattering. Yet, the idea of stocking the tank based on the available niches and physical characteristics is kind of a cool, educational, and ultimately very gratifying process. I just think it's truly amazing that we're able to actually do this these days.

And the sequence that you stock your tank in is extremely pertinent.

I think that you could literally create a sort of "sequence" to stocking various types of fishes based on the stage of "evolution" that your aquarium is in, although the sequence might be a bit different than Nature in some cases. For example, in a more-or-less brand new aquarium, analogous in this case to a newly-inundated forest floor, their might be a lot less in the way of lower life forms, such as fungi and bacteria, until the materials begin breaking down. You'd simply have an aggregation of fresh leaves, twigs, seed pods, soils, etc. in the habitat.

So, if anything, you're likely to see fishes which are much more dependent upon  allochthonous from the terrestrial environment. This is a compelling way to stock an aquarium, I think. Especially aquarium systems like ours which make use of these materials en masse.

Right from the start (after cycling, of course!), it would not be unrealistic to add fishes which feed on terrestrial fruits and botanical materials, such as Colossoma, Arowanna, Metynis, etc. Fishes which, for most aquarists of course, are utterly impractical to keep because of their large adult size and/or need for physical space!

(Pacu! Image by Rufus46, used under CC BY-SA 3.0)

Now, a lot of smaller, more "aquarium suited" fishes will also pick at these fruits and seeds, so you're not totally stuck with the big brutes if you want to go this route! Interestingly, the consumption and elimination of fruits by fishes is thought to be a major factor in the distribution of many plants in the region.

Do a little research here and you might be quite surprised about who consumes what in these habitats!

More realistically for most aquarists, I'd think that you could easily stock first with fishes like surface-dwelling (or near surface-dwelling) species, like hatchetfishes and some Pencilfishes, which are largely dependent upon terrestrial insects such as flies and ants, in Nature. In other words, they tend to "forage" or "graze" little, and are more opportunistic, taking advantage of careless insects which end up in the water of these newly-inundated environs.

I've read studies where almost 100 species were documented which feed near-exclusively on insects and arthropods from terrestrial sources in these habitats! As I mention often, if you dive a bit deeper than the typical hobbyist writings, and venture into scholarly materials and species descriptions, you'll be fascinated to read about the gut-content analysis of fishes, because they give you a tremendous insight about what to feed in the aquarium!

Continuing on, it's easy to see that, as the environments evolve, so does the fish population. And the possibilities for simulating this in the aquarium are many and are quite interesting!

Later, as materials start to decompose and are acted on by fungi and bacteria, you could conceivably add more of the "grazing" type fishes, such as Plecos, small Corydoras, Headstanders, etc.

As the tank ages and breaks in more, this would be analogous to the period of time when micro-crustaceans and aquatic insects are present in greater numbers, and you'd be inclined to see more of the "micropredators" like characins, and ultimately, small cichlids.

Interestingly, scientists have postulated that evolution favored small fishes like characins in these environments, because they are more efficient at capturing small terrestrial insects and spiders in these flooded forests than the larger fishes are!

And it makes a lot of sense, if you look at it strictly from a "density/variety" standpoint- lots of characins call these habitats home!

Then there are detritivores.

The detrivorus fishes remove large quantities of this material from submerged trees, branches, etc. Now, you might be surprised to learn that, in the wild, the gut-content analysis of almost every fish indicates that they consume organic detritus to some extent! And it makes sense...They work with the food sources that are available to them!

At different times of the year, different food sources are easier to obtain.

And, of course, all of the fishes which live in these habitats contribute to the surrounding forests by "recycling" nutrients locked up in the detritus. This is thought by ecologists to be especially important in blackwater inundated forests and meadows in areas like The Pantanal, because of the long periods of inundation and the nutrient-poor soils as a result of the slow decomposition rates.

All of this is actually very easy to replicate, to a certain extent, when stocking our aquaria. Why would you stock in this sort of sequence, when you're likely not relying on decomposing botanicals and leaves and the fungal and microbial life associated with them as your primary food source?

Well, you likely wouldn't be...However, what about the way that the fishes, when introduced at the appropriate "phase" in the tank's life cycle- adapt to the tank? Wouldn't the fishes take advantage of these materials as a supplement to the prepared foods that you're feeding them? Doesn't this impact the fishes' genetic "programming" in some fashion? Can it activate some health benefits, behaviors, etc?

I believe that it can. And I believe that this type of more natural feeding ca profoundly and positively impact our fishes' health.

I’m no genius, trust me. I don’t have half the skills many of you do but I have succeeded with many delicate “hard-to-feed” fishes over my hobby “career.” 


Because I'm really patient.

Success with this approach is simply a result of deploying "radical patience."  The practice of just moving really slowly and carefully when adding fishes to new tanks. 

It's a really simple concept.

The hard part is waiting longer to add fishes.

Wait a minimum of three weeks—and even up to a month or two if you can stand it, and you will have a surprisingly large population of micro and macro fauna upon which your fishes can forage between feedings.

Having a “pre-stocked” system helps reduce a considerable amount of stress for new inhabitants, particularly for wild fishes, or fishes that have reputations as “delicate” feeders.

And think about it. This is really a natural analog of sorts. Fishes that live in inundated forest floors (yeah, the igapo again!) return to these areas to "follow the food" once they flood.

It just takes a few weeks, really. You’ll see fungal growth. You'll see some breakdown of the botanicals brought on by bacterial action or the feeding habits of small crustaceans and fungi. If you "pre-stock", you might even see the emergence of a significant  population of copepods, amphipods, and other creatures crawling about, free from fishy predators, foraging on algae and detritus, and happily reproducing in your tank.

We kind of know this already, though- right?

This is really analogous to the tried-and-true practice of cultivating some turf algae on rocks either in or from outside your tank before adding herbivorous, grazing fishes, to give them some "grazing material." 

Radical patience yields impressive results.

It’s not always easy to try something a little out of the ordinary, or a bit against the grain of popular practice, but I commend you for even thinking about the idea. At the very least, it may give you pause to how you stock your tank in the future, like  "Herbivores first, micro predators last", or whatever thought you subscribe to. 

Allow your system to mature and develop at least some populations of fauna for these fishes to supplement their diets with. You’ll develop a whole new appreciation for how an aquarium evolves when you take this long, but very cool road.

Stay patient. Stay observant. Stay creative. Stay studious. Stay resourceful...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


Letting go...

So, you have this idea for an aquarium.

You kind of see it in your'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.


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.


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 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?


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 the right way.

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

And Stay Wet.


Scott Fellman
Tannin Aquatics 

It's only a "fail" if you make it one...

Part of the aquarium hobby experience is screwing stuff up.

There are so many things that we do as aquarists which involve variables beyond our control, that failure in some things is almost inevitable.

And, after a lifetime in the hobby, I will occasionally reflect back on some of the great successes that I’ve had...and on some of the many, many failures that I’ve been involved with! Failures aren’t that bad, really. In fact, they're pretty damn helpful...As the sayings goes, “Nothing is ever wasted- it can always serve as an example of what NOT to do!”


Yeah, because if you learn from them, failures or disasters are extremely valuable tools for self-education.

I was thinking about my worst-ever aquarium disasters, and, fortunately, there have not been all that many...However, the ones I have had have been notable...and very educational!

My biggest mistakes came out of my own arrogance, really. Yes, arrogance. A desire to flaunt the "rules" set by Nature. 

Usually, they were "created" when I tried to do something that disregarded simple logic (and a century of aquarium common sense), like trying mixes of fishes that were absurd, or overstocking tanks...stuff like that.

For example, from my reef keeping experience- not all that many years ago, actually- I was going to be the ONE reefer to keep several Centropyge angelfish in his reef, including a Lemonpeel, Vrolicki, Coral Beauty, Flame Angel, and Bicolor! If you don't know anything about the dwarf angelfish of the genus Centropyge, the one thing you SHOULD know is that they are very territorial, and don't generally get along with others of their own species. And mixing different species is a traditional "recipe"  for disaster.

Oh, and most of the ones I wanted to keep had a well-earned reputation for snacking on coral tissue...What could go wrong here?

This was a recipe for failure that even the most inexperienced reefer could see coming. Of course, I was "experienced", so I knew better, right?


Nonetheless, I really thought I could pull this off in a large reef with specialized aquascaping... I was convinced that it could work and that I'd be the envy of the reef aquarium world for doing so...Not only did this experiment end with some "predictable" results (a lot of nice corals getting snacked on), it resulted in 5 very ticked-off, very beaten up dwarf angels! No shit? Who would have seen that coming, right?

Just plain stupid...For some reason, I really thought that my “methodology” would pay off and that it could work...WRONG.

But hey. I did it. I failed at it. I OWN it.

I distinctly remember a dubious experiment on the side of my parents' house one summer when I was a teen, attempting to culture mosquito larvae...yeah, you know how well THAT went down!  I think that was the most mosquito bites I've ever had in one summer...

But I learned my lesson....

Or the time I tried to build my own fluidized reactor. It sounded like noble project, but the reality was that I started with a bad concept and used cheap PVC materials that didn't quite match up. Yeah, it didn’t work, and the resulting leaks and total lack of functionality reflected my DIY "skills!" It was a good thought, but really poor on the "execution" side.

Completely unlike the Angelfish fiasco, which was a “lose-lose” proposition! Nowadays, if I have the urge to do DIY, I simply break out the credit card and purchase whatever it is I was thinking of making. Aquarium equipment manufacturers LOVE me!

Another lesson learned.

Oh, or there was that time I tried to make a continuous-feed brine shrimp hatcher...Shit, do you know how LONG it takes to get brine shrimp eggs out of the water column in your tank?

A really long time.

Enough said.

However, failing- and I mean this in the most literal sense- can actually be beneficial in so many ways, especially if you share your failures publicly. Right now, somewhere out in the aquarium hobby world, there is another hobbyist contemplating one of the same absurd, disaster-inevitable ideas that you brought to life...

Perhaps it's not some huge, epic-disaster-bound system failure...Maybe, it's just something that's a bad decision; one that should be aborted on, but isn't likely to be- and the outcome is already well known in the hobby...


Maybe it's in our nature as hobbyists; we just love to tempt fate. And look, I get it...I've written on these very pages that sometimes, we need to go against the grain and try new ideas.

Even after 6 years of pushing this idea of botanical-style aquariums, we're still learning some new ideas, creating "best practices", and evolving techniques. We still make a few mistakes. And, like many hobbyists, we're still trying to get our heads around the "big picture" of the approach, which seems so contradictory to what has been passed down as "the way to do stuff" in the hobby for generations. 

It makes many people uncomfortable to take leaps of faith. And, sure, despite the successful implementation of these techniques for several years by thousands of hobbyists, there is always a chance of failure.

It's scary. It can be viewed as "irresponsible" by some. At the very least, you might question the efficacy and safety of some of this stuff.

It makes sense.

We ask you to make a lot of mental shifts accept some ideas which seem to go "against the grain" of long-held hobby "best practices" and philosophies of aquarium management.

We ask you to understand what you are doing what you are doing, and what the rationale behind the approach is.


One thing that you do get when ideas are shared like this is the benefit of the body of work; the experience- good and bad- of a large community of hobbyists who have went down this same path. The key to taking an idea from "fringe" to "best practice" is sharing. 

Sharing of mistakes made, the refinements done, and the "tweaks" that yielded consistent success.

It starts by creating a hobby culture of sharing.

Sharing of our mistakes is every bit as important as sharing our amazing successes.

So imagine, for a moment, if you do a quick “confessional” post on Instagram or Facebook about your biggest aquarium screw up, and just one hobbyist who is contemplating a similar thing stumbles on it, and then decides NOT to recreate your disaster!

Think of the savings in money, frustration, and innocent animals’ lives...It’s all good. "Failure" makes you a more successful aquarist- IF you learn from the mistake, and IF you share it with others!

It's kind of fun, too!

So, don’t hide your failures.

Discuss them.

Trumpet them from the highest mountain. Savor them. Run around, scream, share, yell at people if you must...But tell ‘em that you screwed something up...Tell them how, why, and what it was that you did to screw it up! 

Then laugh about it and feel better! Look at the absurdity of the thing you did.

Of course, some seemingly counter-intuitive ideas do work.

Sometimes, you try something that YOU think will be a mess, but your friends know will work, because they've done it many times, and have refined the idea and practices. You're a bit scared...and you do it anyways based on their ideas!  And it DOES work! Like recently, when my friend convinced me to try several male Apistos of different species in my display tank...I was like, "Dude...really?"

And he said, "Trust me."  And I did. And it was awesome!

Think about "failure" in the context of the bigger picture...

The neat thing about mistakes, screw-ups, and "failures" is that they often lead to something far, far better than whatever it was that you initially failed at. Because, if you take the time to ask yourself why it happened, and reconstruct the process, and make necessary adjustments and recalibration, you'll often find that the idea can work- just in a slightly different manner than you originally thought. 

And failures are only failures if you don't learn from them.

Even in our business, we screw up shit all the time, and usually it's our own fault. And we try to learn from them and refine our processes to make sure that they don't happen again.

In fact, I've been working on a piece on the many screw-ups we’ve made here at Tannin. It’s actually kind of funny, because there ARE so many! 

"Marketing blasphemy", you say? No. Not at all. Rather, it’s a living embodiment of practicing what we preach...

As humans, we all make bad decisions from time to time. Some are the result of pushing boundaries...others are simply bad judgement. Again, how the mistake was made isn't quite as important as learning from it is.

We will all benefit from being human, being honest, and getting through our trials and tribulations in fish keeping together. And yeah, we all have more to gain than to lose from sharing our mistakes.

Trust me.

What’s the biggest screwup- the worst mistake- that you’ve made in aquarium keeping? What did you learn from it?

Don’t be shy. Own it. Share it. Your "failure" will likely lead to others succeeding...So, it wasn’t really a failure after all, right?


Stay bold. Stay thoughtful. Stay honest. Stay curious. Stay experimental...

And Stay Wet.


Scott Fellman

Tannin Aquatics

The Botanical-Style Aquarium: A "filter" of its own, and other biological musings...

A big thought about our botanical-style aquariums:

The aquarium-or, more specifically- the botanical materials which comprise the botanical-style aquarium "infrastructure" acts as a biological "filter system."

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

Oh, the part about the biofilms and fungal growths sounds familiar, doesn't it?

Let's talk about our buddies, the biofilms, just a bit more. One more time. Because nothing seems as contrary to many hobbyists than to sing the praises of these gooey-looking strands of bacterial goodness!

Structurally, biofilms are surprisingly strong structures, which offer their colonial members "on-board" nutritional sources, exchange of metabolites, protection, and cellular communication. They form extremely rapidly on just about any hard surface that is submerged in water.

When I see aquarium work in which biofilms are considered a "nuisance", and suggestions that it can be eliminated by "reducing nutrients" in the aquarium, I usually cringe. Mainly, because no matter what you do, biofilms are ubiquitous, and always present in our aquariums. We may not see the famous long, stringy "snot" of our nightmares, but the reality is that they're present in our tanks regardless.

The other reality is that biofilms are something that we as aquarists typically fear because of the way they look. In and of themselves, biofilms are not harmful to our fishes. They function not only as a means to sequester and process nutrients ( a "filter" of sorts?), they also represent a beneficial food source for fishes.

Now, look, I can see rare scenarios where massive amounts of biofilms (relative to the water volume of the aquarium) can consume significant quantities of oxygen and be problematic for the fishes which reside in your tank. These explosions in biofilm growth are usually the result of adding too much botanical material too quickly to the aquarium. They're excaserbated by insufficient oxygenation/circulation within the aquarium.

These are very unusual circumstances, resulting from a combination of missteps by the aquarist.

Typically, however, biofilms are far more beneficial that they are reven emotely detrimental to our aquariums.

Nutrients in the water column, even when in low concentrations, are delivered to the biofilm through the complex system of water channels, where they are adsorbed into the biofilm matrix, where they become available to the individual cells.  Some biologists feel that this efficient method of gathering energy might be a major evolutionary advantage for biofilms which live in particularly in turbulent ecosystems, like streams, (or aquariums, right?) with significant flow, where nutrient concentrations are typically lower and quite widely dispersed.

Biofilms have been used successfully in water/wastewater treatment for well over 100 years! In such filtration systems the filter medium (typically, sand) offers a tremendous amount of surface area for the microbes to attach to, and to feed upon the organic material in the water being treated. The formation of biofilms upon the "media" consume the undesirable organics in the water, effectively "filtering" it!

Biofilm acts as an adsorbent layer, in which organic materials and other nutrients are concentrated from the water column. As you might suspect, higher nutrient concentrations tend to produce biofilms that are thicker and denser than those grown in low nutrient concentrations.

Those biofilms which grow in higher flow environments, like streams, rivers, or areas exposed to wave action, tend to be denser in their morphology. These biofilms tend to form long, stringy filaments or "streamers",which point in the direction of the flow. These biofilms are characterized by characteristic known as  "viscoelasticity." This means that they are flexible, and stretch out significantly in higher flow rate environments, and contract once again when the velocity of the flow is reduced.

Okay, that's probably way more than you want to know about the physiology of biofilms! Regardless, it's important for us as botanical-style aquarists to have at least a rudimentary understanding of these often misunderstood, incredibly useful, and entirely under-appreciated life forms.

And the whole idea of facilitating a microbiome in our aquariums is predicated upon supplying a quantity of botanical materials- specifically, leaf litter, for the beneficial organisms to colonize and begin the decomposition process. An interesting study I found by Mehering, et. al (2014) on the nutrient sequestration caused by leaf litter yielded this interesting little passage:

"During leaf litter decomposition, microbial biomass and accumulated inorganic materials immobilize and retain nutrients, and therefore, both biotic and abiotic drivers may influence detrital nutrient content."

The study determined that leaves such as oak "immobilized" nitrogen. Generally thinking, it is thought that leaf litter acts as a "sink" for nutrients over time in aquatic ecosystems.

Oh, and one more thing about leaves and their resulting detritus in tropical streams: Ecologists strongly believe that microbial colonized detritus is a more palatable and nutritious food source for detritivores than uncolonized dead leaves. The microbial growth which occurs on the leaves and their resulting detritus increases the nutritional quality of leaf detritus, because the microbial biomass on the leaves is more digestible than the leaves themselves (because of lignin, etc.).

Okay, great. I've just talked about decomposing leaves and stuff for like the 11,000th time in "The Tint"; so...where does this leave us, in terms of how we want to run our aquariums?

Let's summarize:

1) Add a significant amount of leaf litter, twigs, and botanicals to your aquarium as part of the substrate.

2) Allow biofilms and fungal growths to proliferate.

3) Feed your fishes well. It's actually "feeding the aquarium!"

4) Don't go crazy siphoning out every bit of detritus.

Let's look at each of these points in a bit more detail.

First, make liberal use of leaf litter in your aquarium. I'd build up a layer anywhere from 1"-4" of leaves. Yeah, I know- that's a lot of leaves. Initially, you'll have a big old layer of leaves, recruiting biofilms and fungal growths on their surfaces. Ultimately, it will decompose, creating a sort of "mulch" on the bottom of your aquarium, rich in detritus, providing an excellent place for your fishes to forage among. 

Allow a fair amount of indirect circulation over the top of your leaf litter bed. This will ensure oxygenation, and allow the organisms within the litter bed to receive an influx of water (and thus, the dissolved organics they utilize). Sure, some of the leaves might blow around from time to time- just like what happens in Nature. It's no big deal- really!

The idea of allowing biofilms and fungal growths to colonize your leaves and botanicals, and to proliferate upon them simply needs to be accepted as fundamental to botanical-style aquarium keeping. These organisms, which comprise the biome of our aquariums, are the most important "components" of the ecosystems which our aquariums are.

I'd be remiss if I didn't at least touch on the idea of feeding your aquarium. Think about it: When you feed your fishes, you are effectively feeding all of the other life forms which comprise this microbiome. You're "feeding the aquarium." When fishes consume and eliminate the food, they're releasing not only dissolved organic wastes, but fecal materials, which are likely not fully digested. The nutritional value of partially digested food cannot be understated. Many of the organisms which live within the botanical bed and the resulting detritus will assimilate them.

Now, we could go on and on about this topic; there is SO much to discuss. However, let's just agree that feeding our fishes is another critical activity which provides not only for our fishes' well-being, but for the other life forms which create the ecology of the aquarium.

And, let's be clear about another thing: Detritus, the nemesis of many aquarists- is NOT our enemy. We've talked about this for several years now, and I cannot stress it enough: To remove every bit of detritus in our tanks is to deprive someone, somewhere along the food chain in our tanks, their nutritional source. And when you do that, imbalances occur...You know, the kinds which cause "nuisance algae" and those "anomalous tank crashes."

The definition of this stuff, as accepted in the aquarium hobby, is kind of sketchy in this regard; not flattering at the very least:

"detritus is dead particulate organic matter. It typically includes the bodies or fragments of dead organisms, as well as fecal material. Detritus is typically colonized by communities of microorganisms which act to decompose or remineralize the material."

Shit, that's just bad branding.

The reality is that this not a "bad" thing. Detritus, like biofilms and fungi, is flat-out misunderstood in the hobby.

Could there be some "upside" to this stuff? 

Of course there is. 

I mean, even in the above the definition, there is the part about being "colonized by communities of microorganisms which act to decompose or remineralize..."

It's being processed. Utilized. What do these microorganisms do? They eat it...They render it inert. And in the process, they contribute to the biological diversity and arguably even the stability of the system. Some of them are utilized as food by other creatures. Important in a closed system, I should think.

This is really important. It's part of the biological operating system of our botanical-style aquariums. I cannot stress this enough. 

Now, I realize that the idea of embracing this stuff- and allowing it to accumulate, or even be present in your system- goes against virtually everything we've been indoctrinated to believe in about aquarium husbandry. Pretty much every article you see on this stuff is about its "dangers", and how to get it out of your tank. I'll say it again- I think we've been looking at detritus the wrong way for a very long time in the aquarium hobby, perceiving it as an "enemy" to be feared, as opposed to the "biological catalyst" it really is!

In essence, it's organically rich particulate material that provides sustenance, and indeed, life to many organisms which, in turn, directly benefit our aquariums.

We've pushed this narrative many times here, and I still think we need to encourage hobbyists to embrace it more.

Yeah, detritus.

Okay, I'll admit that detritus, as we see it, may not be the most attractive thing to look at in our tanks. I'll give you that. It literally looks like a pile of shit! However, what we're talking about allowing to accumulate isn't just fish poop and uneaten food. It's broken-down materials- the end product of biological processing.  And, yeah, a wide variety of organisms have become adapted to eat or utilize detritus.

There is, of course, a distinction.

One is the result of poor husbandry, and of course, is not something we'd want to accumulate in our aquariums. The other is a more nuanced definition. 

As we talk about so much around here- just because something looks a certain way doesn't mean that it alwaysa bad thing, right?

What does it mean? Take into consideration why we add botanicals to our tanks in the first place. Now, you don't have to have huge piles of the stuff littering your sandy substrate. However, you could have some accumulating here and there among the botanicals and leaves, where it may not offend your aesthetic senses, and still contribute to the overall aquatic ecosystem you've created.

If you're one of those hobbyists who allows your leaves and other botanicals to break down completely into the tank, what really happens? Do you see a decline in water quality in a well-maintained system? A noticeable uptick in nitrate or other signs? Does anyone ever do water tests to confirm the "detritus is dangerous" theory, or do we simply rely on what "they" say in the books and hobby forums?

Is there ever a situation, a place, or a circumstance where leaving the detritus "in play" is actually a benefit, as opposed to a problem?

I think so. Like, almost always.

Yes, I know, we're talking about a closed ecosystem here, which doesn't have all of the millions of minute inputs and exports and nuances that Nature does, but structurally and functionally, we have some of them at the highest levels (ie; water going in and coming out, food sources being added, stuff being exported, etc.).

There is so much more to this stuff than to simply buy in unflinchingly to overly-generalized statements like, "detritus is bad."

The following statement may hurt a few sensitive people. Consider it some "tough love" today: 

If you're not a complete incompetent at basic aquarium husbandry, you won't have any issues with detritus being present in your aquarium.


Don't overstock.

Don't overfeed.

Don't neglect regular water exchanges.

Don't fail to maintain your equipment.

Don't ignore what's happening in your tank.

This is truly not "rocket science." It's "Aquarium Keeping 101."

And it all comes full circle when we talk about "filtration" in our aquariums.

People often ask me, "What filter do you use use in a botanical-style aquarium?" My answer is usually that it just doesn't matter.  You can use any type of filter. The reality is that, if allowed to evolve and grow unfettered, the aquarium itself- all of it- becomes the "filter." 

You can embrace this philosophy regardless of the type of filter that you employ.

My sumps and integrated filter compartments in my A.I.O. tanks are essentially empty.

I may occasionally employ some activated carbon in small amounts, or throw some "Shade" sachets in there if I am feeling it- but that's it. The way I see it- these areas, in a botanical-style aquarium, simply provide more water volume, more gas exchange; a place for bacterial attachment (surface area), and perhaps an area for botanical debris to settle out. Maybe I'll remove them, if only to prevent them from slowing down the flow rate of my return pumps.

But that's it. 

A lot of people are initially surprised by this. However, when you look at it in the broader context of botanical style aquariums as miniature ecosystems, it all really makes sense, doesn't it? The work of these microorganisms and other life forms takes place throughout the aquarium.

I admit, there was a time when I was really fanatical about making sure every single bit of detritus and fish poop and all that stuff was out of my tanks. About undetectable nitrate. I was especially like that in my earlier days of reef keeping, when it was thought that cleanliness was the shit!

It wasn't until years into my reef keeping work, and especially in my coral propagation work, that I begin to understand the value of food, and the role the it plays in aquatic ecosystems as a whole. And that "food" means different things to different aquatic organisms. The idea of scrubbing and removing every single trace of what we saw as "bad stuff" from our grow-out raceways essentially deprived the corals and supporting organisms of an important natural food source.

We'd fanatically skim and remove everything, only to find out that...our corals didn't look all that good. We'd compensate by feeding more heavily, only to continue to remove any traces of dissolved organics from the water...

It was a constant struggle- the metaphorical "hamster wheel"- between keeping things "clinically clean" and feeding our animals. We were super proud of our spotless water. We had a big screen when you came into our facility showing the parameters in each raceway. Which begged the question: Were we interested in creating sterile water, or growing corals? 

Eventually, it got through my thick skull that aquariums- just like the wild habitats they represent-are not spotless environments, and that they depend on multiple inputs of food, to feed the biome at all levels. This meant that scrubbing the living shit (literally) out of our aquariums was denying the very biotia which comprised our aquariums their most basic needs.

That little "unlock" changed everything for me.

Suddenly, it all made sense. 

This has carried over into the botanical-style aquarium concept: It's a system that literally relies on the biological material present in the system to facilitate food production, nutrient assimilation, and reproduction of life forms at various trophic levels.

It's changed everything about how I look at aquarium management and the creation of functional closed aquatic ecosystems. 

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

It means adopting a different outlook, accepting a different, yet very beautiful aesthetic. It's about listening to Nature instead of the asshole on Instagram with the flashy, gadget-driven tank. It's not always fun at first for some, and it initially seems like you're somehow doing things wrong.

It's about faith. Faith in Mother Nature, who's been doing this stuff for eons.

It's about nuance.

It's about looking at things a bit different that we've been "programmed" to do in the aquarium hobby for so long. It's about not being afraid to question the reasons why we do things a certain way in the hobby, and to seek ways to evolve and change practices for the benefits of our fishes. 

It takes time to grasp this stuff. However, as with so many things that we talk about here, it's not's simply an evolution in thinking about how we conceive, set up, and manage our aquariums. 


Sure, the aquairum is a "filter" of sorts, if you want to label it as such. However, it's so much more: A small, evolving ecosystem, relying on natural processes to bring it to life.

Wrap you head around that.

It might just change everything in the hobby for you.

Stay open-minded. Stay thoughtful. Stay bold. Stay curious. Stay diligent. Stay observant...

And Stay Wet.


Scott Fellman

Tannin Aquatics 





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