June 23, 2022



Not long ago, I was perusing a hobby forum on “blackwater aquariums” , and an aquarist was asking for “inspiration” for an “Amazonian-themed blackwater flooded forest aquarium.”

Okay, that's always cool...Anything "Amazon-themed" or "flooded forest" always sort of catches my attention! And "blackwater" kind of gets to me...

And, predictably, a bunch of hobbyists chimed in to help- because hobbyists are kind that way. They shared photos of a variety of what they called “Amazonian- themed blackwater” aquariums, which, sadly, not only didn’t have “blackwater”type conditions- they bore almost no resemblance to any actual natural aquatic habitat- blackwater flooded forest, or otherwise.  

Some of the responses were downright boastful and seemingly authoritative, with more than one literally stating that, "...this is how you should do it if you want this type of tank..." And, they looked like all of the other other "Amazon-Themed" tanks you see on social media...Superficial at best...downright inaccurate at the worst.


The effort by most of the respondents was sincere, but the tragedy in all of this was that no one thought to share a single picture of a natural Aquatic habitat.

Or even a recommendation to search Google for one! Virtually any pic of a natural (blackwater) habitat would provide endless inspiration. At the very least, it would have opened up more discussions; perhaps led to some different questions. Questions which could have led to some shared experiences, greater understanding, and maybe- some new ideas on how to execute an aquarium representing this amazing habitat.

Yet, it turned into the usual regurgitated copy-fest of assorted aquariums, and discussion on how to replicate the look of them.  It was disappointing enough that none of the tanks in the discussion remotely "looked" like the wild habitat the questioner was intrigued by- and even more disappointing that the discussion was about how to replicate the tanks-not the habitat!

Yeah, a desire to replicate the look of an aquarium purportedly based upon a natural habitat (which it didn't really resemble at all, in form or function)? Like, WTF?! 

How does this happen?

I think that it's because we as a hobby are, well-  lazy.

Seriously. I know that sounds harsh, but it's true, IMHO.

With few exceptions, most hobbyists generally don't make the effort to do their own research- or any research, for that matter, other than asking for pics of someone else's tank. It's a real tragedy, because with minimal effort, even the visuals of a natural ecosystem could provide cues and topics to further research that will help hobbyists really understand what they're contemplating!

Now, I realize that this can easily turn into another "grumpy 'ol Scott rant telling the neighborhood kids to get off his lawn", but that's not the point. And, I do realize that not everyone wants to create an aquarium filled with leaves and soil and decomposing muck, and that not every aquarium representing one of these habitats has to be that way. However, the greater issue is when our hobby understanding of these habitats is based wholy on someone's aquarium, which may bare little, if any resemblance to the actual environment it intends to "replicate." 

Then what happens is that we perpetuate misinformation- even when unintended. We continue to push dumbed-down or superficial information about these habitats and the practices required if we truly want replicate them functionally, not just aesthetically. I mean, enjoy the hobby hope you want to- but don't perpetuate the bad information that's already out there in the process. 

I think we need to spend way more time as hobbyists actually looking at Nature for our inspiration- not only for the “aesthetics”- but to study and understand the function. To learn about why these habitats function and look the way they do. It’s the “unlock”- the key to everything!

Look, you may love the way they look, respect and understand the function- and still choose to create a tank "inspired" by them. And that's perfectly okay. I do it all the time. My tanks don't precisely replicate many of the habitats they represent. I don't want try to manage a 4.3pH ecosystem, despite how accurate it may be. I do, however, understand these systems on some levels, and I certainly make the effort to learn about, and replicate when possible, the ecology where they occur.

But I don't defectors declare my tanks as the ultimate representation ration of a specific habitat. 

Maybe I "pick and choose"what I care to work with- which a lot of us do. And that's fine. 

What I don't do-what NONE of us should do- is make declarative statements about my way being "the best" way or the "only" way to do something, and I don't espouse that any other approach is incorrect or "wrong"- that's just being an asshole.  

It doesn't help anyone. 

It's perfectly fine to do whatever you want and call your work whatever- I mean, if your tank has 6 different species of fishes from the Amazon, it's decidedly an "Amazon-themed" tank, but to literally imply that your work is the epitome of accuracy is just absurd. It's NOT fine when you're dogmatically telling people that your tank something that it's not, and inferring that if they don't replicate your work, they somehow "not doing things correctly."

It's important for us to refer to research and information from outside of the aquarium hobby. Otherwise, this just becomes an echo chamber where we keep bouncing around the same assertions, regardless of accuracy. Google Scholar and other scientific research aggregator sites are really helpful- and you'd be surprised just how much stuff there is on the most arcane topics that you're trying to learn about. I can't begin to tell you how many times I've made use of these priceless resources for my work!

Now sure, some of this stuff is often dry, filled with academic language and references, and might be difficult for us non-scientist to follow...But if you persevere and stay at it, you can uncover some real gems that will help you in ways you might not have thought about. An example for me was a paper containing the orginal description and type locality of Tucanoichthys tucano; a paper which gave me the information which I needed to create what I would proudly call one of my finest and most iconic aquairums (jokingly referred to as the "Tucano Tangle"- but the name sorta stuck, lol).


I've made this plea before- but I think it's vitally important to go beyond what's "easy."

I realize that finding your info on YouTube is convenient, and that there are some great channels out there- but more often, it's filled with inaccuracies and even vacuous drivel. You need to do a few more "technical" searches to see what I mean. Trust me- once you find one of those hidden gems in scholarly articles- it'll change the way you get your information! 

Yeah, inspiration comes from all sorts of sources.

Some of them are just a bit more "original" than others.

Seek them out. Learn from them. Be inspired by them.

Stay curious. Stay diligent. Stay excited...

And Stay Wet.


Scott Fellman

Tannin Aquatics 







June 15, 2022


How soon is...NOW?

We hear a lot of discussions about establishing botanical method aquariums, yet a lot fewer ones about running them over extended periods of time. Occasionally, someone will ask me when a botanical method aquarium is considered "mature" or "finished."

Like, how do you know, and how long should you expect it to take to get there? When can you declare, "NOW the tank is "finished!"

We need to know, apparently.

Now, the question pre-supposes two facts:

1) That there is a quantifiable point where an aquarium can be labeled "finished."

2) That there is even a definition for what "mature" or "finished" means in the aquarium context. 

Of course, part of the "need to know" is actually based upon that human construct of impatience. We need to have something "finished" and not "evolving" or "under construction." This always amuses me, because, in my opinion, an aquarium is never actually "done." It will continue to change and evolve as long as it's kept going by you, the hobbyist. 

And that's a key point: An aquarium keeps evolving as long as we let it...

I believe that part of the need to quantify a tank as "finished" or even "mature" is because we constantly see "professional" aquascapers and content creators setting up tanks, photographing/videoing them, or entering them in a contest, and then breaking them down.

These aquariums definitely have an "expiration date"- and it's due to a single factor:

Human intervention.

It has seeped into the popular perception in the hobby because of the frequent changes in aquariums which many content producers (we're guilty of it, too..) we share in our social media accounts. You set up a tank, get it looking really cool, photograph it ...and then you break it down...and move on to the next one. 

A sort of creative "churn." 

So yeah...It's done! Ready for the next big idea! 

I believe that this constant demonstration of "churning" tanks has "poisoned the well" when it comes to developing patient hobbyists. 

My personal assertion is that an aquarium is never "finished", just as the natural aquatic ecosystems of the world are never "finished", unless outside intervention occurs.

Why can't a YouTuber or "Influencer" set up an aquarium, and document its journey from day one. Just let it evolve? I mean, you can still set up 35 different trendy tanks in the mean time...just keep documenting the one tank as a "proof of concept" that patience, time, Nature, and leaving the tank alone actually works!

I think that audiences can actually handle it.

There are plenty of daily "new looks" in every botanical method aquarium when you leave it alone, trust me. It's constantly evolving and changing...just like in Nature.

IMHO, there is a certain absurdity about the way we document our tanks, anyways. We fail to realize that what many "content creators" often do is to simply glam up their tanks for a video or contest, and then just let the thing go. At best, even a "contest scape" or a video or social media post of an"influencer's" tank only captures a moment in time. it will literally continue to change and evolve even seconds following the photos are taken or the video images are filmed! 

Now, I realize that an "aquascape" in aquarium parlance is a human construct, and can be defined as "finished" when you are satisfied with the configuration you've created and stop "tweaking" it.  In other words, the hardscape (wood or rocks) will not change its configuration or structure on its own!

But that's not the entire story, right?


When you throw living, growing elements like aquatic plants, or materials which decompose, such as leaves and botanicals, into the mix, the appearance of the "aquascape" keeps changing, both aesthetically- and more important- ecologically.


This is precisely why I constantly reiterate the fact that a botanical method aquarium is interesting and beautiful at every phase of its existence! 

To be perfectly honest, the beauty of a botanical method aquarium is that it's never really finished. Each day, each month- the aquarium will continue to evolve and change physically and ecologically- and will do so indefinitely. 

That's why we preach patience so much in our world. Patience to watch your tank go though its developmental changes and evolutions- and the patience to understand and savor each phase of its development. Patience to NOT intervene or interfere with this process.

And an understanding that Nature is "at the controls" for a lot of it...and that it's okay for us to "get out of the way" and let Her do the job, as she has for millennia in the wild aquatic habitats of the world.

Nature manages to work with all sorts of materials, conditions, and constraints, and somehow always finds a way to continue to evolve them in ways that assure its survival over the long term. Our aquariums- although artificial contracts- are still beholden to natural laws and influences, and will contuse to do the same until such time as we decide to break them down.


On the other hand, if you look at an aquarium as you would a garden- an organic, living, evolving, growing entity- then the need to see the thing "finished" becomes much less important. Suddenly, much like a "road trip", the destination becomes less important than the journey. It's about the experiences gleaned along the way.

Enjoyment of the developments, the process.

When it comes to leaves and seed pods, some will simply last longer than others. All will contribute to the richness and diversity in their own way. Some replace others over time as the more "dominant" component of your natural "hardscape", wether fostered intentionally by you replacing stuff, or by natural decomposition changing a botanical into a different form, which newly added ones take over. All form a part of the whole, rich, ever-evolving picture.

This is why I never get freaked out about cloudy water, tons of fungal growth on my wood or leaves, or other processes which impact the aesthetics of my tanks early on in their life. Just wait a while, it'll change. And rather than be reviled by all of those stringy fungal growths, think about why they appear, what they're doing, and how you see the same exact thing in the wild aquatic habitats we love so much.

An appreciation of where you are sort of blunts the need to have a "finish line", in my opinion. 

It makes sense when you consider it in that context. Sure.

Yet, people new to our little hobby sector still often ask me, "When will my tank start looking more "broken in'?", or, "When can I add more fishes?", or, "When will the tank look more established?"

My answer to these kinds of questions is always the same: It takes a while.

Botanical-method aquariums, like any other, require biological processes to establish and "mature" the system. This takes more than a week, or two weeks- or even a month. Honestly, if you asked me, you're talking three to four months before any aquarium- especially a botanical-method one- hits that "stride" of stability and the "look" that comes from a more mature, established system.

Three to four months. 

Like, one full season.

Can you handle that? 

I mean, it's really not that long, right? Especially when you take into account that you can maintain a botanical-method aquarium continuously for years. 

And we're not in this just to create a "look." The reality is that many botanical method aquariums, which embrace stuff like sediments and decaying leaves and such, look "mature" very early on. 

But that's not the whole game here, right? It's one thing to look mature, another for an aquarium to be ecologically stable and diverse.

You can get there easily, really. 

It just requires patience, a long-term vision, and a focus on the goal of establishing a healthy, naturally-functioning system over the long term. You can't rush stuff. You simply can't. And you really don't want to, anyways. Let it evolve naturally.

Stay the course.

Be patient. 

One day, you'll look at your tank, and think to yourself, "THIS is what I envisioned!" And you might casually glance at the calendar and note that, sure enough- it's been about 3-4 months since you established your tank.

Not all that long, right? 

It was a pretty enjoyable ride along the way, wasn't it? Yeah, when you liberate yourself from some artificially self-imposed timetable about "when" things will look/feel good, it's a lot easier.

Yeah, we're talking about the appearance- but it's also about the function, right?

And it all comes back to understanding and embracing the fundamentals. 

I firmly believe that understanding and appreciating the fundamentals of the hobby- and the natural world- can yield the same results- or better- than tons of expensive gear and "stuff" when simply "thrown" at the situation without thought as to why..

It requires us to shift our minds to places that might be less comfortable for us...

It just is a lot less sexy than "gearing up" or blindly following someone else's "rules"- it requires us to open our minds up...It requires patience, process and personal observation. It requires eschewing more "instant" result for long-term function, stability, and benefits.

That mental shift is something, isn't it?

Although the "I want the tank to be 'done' NOW!" mindset- although still highly visible and perpetuated by numerous vapid, moronic posts on social media is still top of mind to many, there are signs that the greater hobby is waking up to the fact that you can't have an "instant awesome" established, ecologically rich aquarium in a matter of days. 

I think the pendulum in the hobby is swinging back a bit.

Not "digressing", mind you. Evolving; with hobbyists starting to grasp that anyone can create an amazing aquarium- it's just that it takes some understanding and process..and time. And realization that every stage of an aquariums evolution can be compelling.

And I can feel that many hobbyists are switching back to a more "accepting" approach; taking our hands off...just a bit, and letting Nature do what She does so well without our "editing." Once again realizing that Nature knows best. Understanding that we can use technology and technique to work with Nature. 

We are learning that the journey- the evolution- of an aquarium is the whole game here. And that the "finish line" is really an artificial construct...a figment of our imaginations.

So, IS there even a "finish line" to an aquarium? Is an aquarium ever "finished?"

Only if we make it that way. 

Nature won't stop.

You shouldn't, either.

Stay patient. Stay thoughtful. Stay bold. Stay diligent...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


Living Color

The other day, in our Instagram feed, we received what I felt was one of the most honest, amazing comments I'd ever seen. The commenter was acknowledging that, while he loved the tinted water which botanical-method aquariums yield, he was having a bit of a mental struggle at the dark water hiding some of the subtle colors in his fishes. He loved the look, but was bummed out that his colorful fishes weren't as discernible in the deeply tinted water.  He was sort of torn...He wanted to know if I ever had a similar feeling.

Besides just loving the incredible honesty, the comment did make me think a bit. 

Now, I can honestly say that it never actually bothered me. In fact, I DID have to think a lot about it- but it was mainly for the reason that I couldn't think of a time when it did! I guess I always was drawn so much to the habitat, that any perceived loss of color was a non issue. I think that I'm also naturally attracted to fishes which, although can be colorful, generally have more muted patterns intended to help them blend into their environment. 

However, I do agree that the tinted waters which result when we add leaves, seed pods, soils, etc, into our aquariums definitely impact the "visuals" of our fishes, don't they? Anyone who's ever tried to take a pic or video of his or her botanical method aquarium can attest to this. It's hard to get a good pic showing all of the accurate colors of some of your fishes. 

On the other hand, some fishes seem to take on an entirely new appearance in tinted water, and the function of the coloration makes more sense in this context. 

There is a reason as to why this is...

From a paper by researcher Shiro Kohima about the coloration of none other than the blackwater-dwelling Neon Tetra, the conclusion was pretty darned clear:

"To clarify the ecological function of this coloration, we examined the appearance of living neon tetra. They changed color in response to lighting and background conditions, and became less conspicuous under each condition to the human eye. Although they appeared bright in colorless clear water, their stripes appeared darker in blackwater. In addition, the visible area of their stripes was small and their brightness decreased, unless they were observed within a limited viewing angle (approximately 30° above the horizon).

The results show that from the viewpoint of approaching submerged predators, a bright mirror image of the stripes is projected onto the underside of the water’s surface, providing a dramatic visual target while the real fish remains less conspicuous. Based on these results, we hypothesize that the neon tetra’s bright coloration is an effective predator evasion strategy that confuses predators using bright mirror images."

Scientists are aware that dissolved organic materials, such as tannins and lignins, which visually tint the water, also absorb all wavelengths of light, yielding that brownish color that we know so well. 

So, yeah, some of the more subtly-colored patterns on fishes will be more difficult to discern in tinted water. What can we do about that? Can we do anything about it?

Well, for one thing, we can adjust the lighting within our aquariums, and simply ramp up color and intensity. This is where modern LED lighting fixtures work so very well. You'll have to do some experimentation, but the versatility of LED's makes it easy!

Remember, all of this revolves around the properties of the water itself. Indeed, in our tanks, the water itself becomes a part of the attraction, doesn't it? And it becomes a consideration if you're trying to keep aquatic plants. You simply need to ramp up intensity to assist with light penetration, as we recently discussed right here on "The Tint."

One of the big discussion points we have in our world is about the color and "clarity" of the water in our botanical method aquariums. We receive a significant amount of correspondence from customers who are curious how much "stuff" it takes to color up their water.

This is so far from "mainstream" aquarium hobby thinking that I just have to laugh sometimes. I mean, those of us in the community of blackwater, botanical-method aquarists seek out tint and "body" in our water...while the rest of the aquatic world- well, they just sort of... freak the fuck out about that, huh?

And beyond just the color, there are other factors to the water which impact the "visuals", right?

Our aesthetic "upbringing" in the hobby seems to push us towards "crystal clear water", regardless of whether or not it's "tinted" or not. And think about it: You can have absolutely horrifically toxic levels of ammonia, dissolved heavy metals, etc. in water that is "invisible", and have perfectly beautiful parameters in water that is heavily tinted and even a bit turbid.

(FYI, WIkipedia defines "turbidity" in part as, "...the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air.")

That's why the long-standing aquarium "mythology" which suggested that blackwater aquariums, or aquariums with tinted water were somehow "dirtier" than "blue water" tanks used to drive me crazy. The term "blackwater" describes a number of things; however, it's not a measure of the "cleanliness" of the water in an aquarium, is it?


Chemical analysis of compounds like ammonia, nitrite, nitrate, and phosphate- and measurements of the conductivity/redox potential of the water are the indicators of its "cleanliness."

Color alone is not indicative of water quality for aquarium purposes, nor is "turbidity." Sure, by municipal drinking water standards, color and clarity are important, and can indicate a number of potential issues...But we're not talking about drinking water here, are we?

No, we aren't! 

(And yes, aquariums with high quantities of organic materials breaking down in the water column add to the biological load of the tank, requiring diligent management. This is not shocking news. Frankly, I find it rather amusing when someone occasionally tells me that what we do as a community is "reckless", and that our tanks look "dirty."

As if we don't see that or understand why our tanks look the way they do? And we do know the color and visual characteristics of are water are the way they are for certain reasons- just NOT because the water is of "low quality." 

There is a difference between "color" and "clarity."

The color is, as you know, a product of tannins and humic acids leaching into the water from wood, soils, and botanicals, and typically is not "cloudy." It's actually one of the most "natural-looking" water conditions around, as water influenced by soils, woods, leaves, etc. is ubiquitous around the world. Other than having that undeniable color, there is little that differentiates this water from so-called "crystal clear" water to the naked eye.

Of course, the water may have a lower pH and general hardness, but these factors have no bearing on the color or visual clarity of the water. And conversely, dark brown water isn't always soft and acidic. You can have very hard, alkaline water that, based on our hobby biases, looks like it should be soft and acid. Color is NO indicator of pH or hardness! Again, it's one of those things where we seem to ascribe some sort of characteristics to the water based solely on its appearance.

As I've mentioned before, a funny by-product of our more recent obsession with blackwater aquariums in the hobby is a concern about the "tint" of the water, and yeah, perhaps even the "flavor" of said water! A by-product of our acceptance of natural influences on the water, and a desire to see a more realistic representation of certain aquatic environments.  

And that means that dark water we love so much.

Natural black waters typically arise from highly leached tropical environments where most of the soluble elements are rapidly removed by heavy rainfall. Materials such as soils are the primary influence on the composition of blackwater. Leaves and other materials contribute to the process in Nature, but are NOT the primary “drivers” of its creation and composition.


Okay, so there we had another discussion of the visual characteristics of water. It's a bit funny that we don't have to think much about water, in terms of "aesthetics" in most typical aquariums.

It's definitely a "botanical method thing."


Yet, it all boils down to the fact that, when we utilize botanical materials in our aquariums for the purpose of influencing the ecology, we also get the "collateral benefit" of tinted water. And in some instances, the tinted water can impact the appearance of the inhabitants.

And that's neither good nor bad. It's just something that "is." 

We as aquarists need to get our heads around the idea, once again, that this type of more natural aquarium brings its own unique aesthetics. And we, as hobbyists can and should learn to embrace them. It's totally okay if we don't, but it's important to understand that what we see in our aquariums is perhaps the truest reflection of Nature.

Something to think about.

Stay observant. Stay open-minded. Stay excited. Stay curious...

And Stay Wet.


Scott Fellman
Tannin Aquatics


June 09, 2022


Why you should be playing with "alternative substrate materials" in your aquariums...

As followers of "The Tint" know, we've been on this heavy "alternative substrate" kick for about 4 years now, pushing out our ideas and creations, sharing the fruits of our research both practically, and by delving into scientific literature. And the result has been a steadily growing interest in creating and managing unique substrates within botanical method aquariums. 

But the roots of our obsession with substrates goes back even farther- like to the earliest days of our company. 

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

Now, a unique class of substrate, the"Podzols"- soils characterized by a whitish-grey subsurface, bleached by organic acids- caught my attention early on, and it led to a lot of cool ideas here. They have an overlying dark accumulation of brown or black illuviated humus. These soils support the rainforests surrounding blackwater streams, yet are the most infertile soils in Amazonia. 


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

And in some instances, to replace them entirely.  

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-method aquarium.

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.


And of course, larger crustaceans and even fishes will consume the organisms which live in this "matrix", as well as possibly consuming some of the detritus from the decomposing leaves themselves. This is precisely what happens in natural systems.

I'm fascinated by the different types of soils or substrate materials which occur in blackwater systems, and how they influence the aquatic environment. Keep in mind that many of the habitats we obsess over, like Amazonian "igapos" and "igarapes" are seasonally-inundated forest-floor features, so it goes without saying that the terrestrial soil composition and associated biomass have significant influence on the aquatic environments that emerge during the wet season.

Its a very different looking- and functioning- substrate, for sure. And it can absolutely be replicated successfully in the aquarium. Adding materials reminiscent of those found in the wild to augment- or completely replace- the more "traditional" sands and other substrates used in aquariums is an easy "mental shift" that we can make and act upon.  

With our embrace of "detritus" or "mulm" as a source of "fuel" for creating active biological systems within the confines of our aquariums, I think that the idea of an "enriched substrate," replete with botanical materials, will become an integral part of the overall ecosystems that we create. Considering the substrate as both an aesthetic AND functional component- especially in "non-plant-focused" aquariums, opens up a whole new area of aquarium "exploration."

I envision that the future of mainstream aquarium practice may include creating such a substrate as simply part of what we do. Adding a mix of botanical materials, live bacterial and small organism cultures, and even some "detritus" from healthy aquatic systems may become how we establish systems. For botanical-method aquariums, which tend to be less plant-focused, establishing the "ecosystem" is very important.

And the idea is not THAT crazy- it's long been practice to add some sand or filter media from established aquariums into new tanks to help "jump-start" necessary biological processes.  It makes sense, and the overall concept is really not that difficult to grasp. And we probably shouldn't get too crazy into understanding every single aspect of this practice. Suffice it to say, something about this practice works, for reasons which we already tangentially understand. 

In a strictly aesthetic sense, the bottom itself becomes a big part of the aesthetic focus of the aquarium as well, with the botanicals placed upon the substrate- or, in some cases, becoming the substrate. Okay, cool. What are some other materials you can play with to create these "alternative" substrates?

How about...twigs?

Twigs are really fascinating to me as a substrate, because not  only do they create an interesting-looking substrate, they provide unique functional benefits as well. They create "interstitial spaces" (defined as "spaces between objects") which create areas for various fauna (small crustaceans, worms, and aquatic insects), as well as a surface for biofilm, algae, and fungal attachment and growth. The matrix offer protection for these organisms to grow.

Of course, it also provides a foraging area for the fishes. A place where they, too can shelter when needed. A place for them to spawn on and in. 

And of course, the twigs will leach tannins and other compounds into the water, which can impact the aquatic environment chemically. And, because of their physical structure, a substrate consisting substantially of twigs can create spaces for leaves and other botanical materials to accumulate, as well as to sequester our friend, detritus- which, as we've discussed repeatedly- is a valuable secondary food source for many species of fishes.

And of course, a mixing of elements - sand, sediments, crushed botanicals, etc., is yet another approach that you can take to creating a very unique and highly functional substrate. Allowing natural processes of decomposition to take place in and on the substrate is considered "best practice" in this approach.

Why? Because if we try to remove the detritus or other "offensive" material from a substrate created for this purpose, we're effectively depriving "someone"- some beneficial organisms- of their food source. Thus, a slowdown- or even a complete breakdown- of the very processes we're trying to foster-occurs.


There is something incredibly beautiful and useful about utilizing these alternative materials in our substrates. They have created an incredible opportunity for us as hobbyists to forge new directions in the hobby. And as a brand, the idea has really pushed me to develop some "off-the-shelf" solutions for hobbyists to experiment with.


I envision that the future of mainstream aquarium practice may one day include creating such a substrate as simply part of what we do. . For botanical method aquariums, which tend to be less plant-focused, establishing the "ecosystem" is very important.

(The part where Scott bitches and "editorializes a bit...)

Now happily, there are a few manufacturers who are starting to release and talk about different types of substrates for use in aquariums other than planted systems. 

It's a good start, helping to fill the gap in what has been a neglected hobby product sector (as we've been pointing out for years here), but it once again has resulted in some of these companies touting aesthetics above all, which, in my opinion, is not just disappointing, but a huge fail for the hobby. It keeps happing like this...

Why companies which tout themselves as "unique" or "progressive" continue to fall back on the vapid, vacuous "aesthetics first" mindset when creating and discussing what could be game-changing products if they just tweaked both the product and the messaging just a bit is beyond me. With the resources some of them have, it makes no sense to me to keep doing this.

Why do they do this? 

I think they do it this way because it's "safe", "easy", and fast to market. When you don't have to educate people on anything more than color and texture choices, all it takes is some capital to acquire and package your product, do a few social media posts, and release it to the YouTube "influencer" crowd- and your an instant "player..."

Ouch. Unfair, perhaps? But entirely correct.

So, hit me up guys, if you need some "consultation", lol. I can get your straightened out... I know that you can do better!😎

Okay, off the well-worn soapbox for now. 

To summarize, I think one of the most "liberating" things we've seen in the botanical-method aquarium niche is our practice of utilizing the substrate itself to become a feature in our aquariums, as well as a functional mechanism for the inhabitants.

In other words, if we do go down the road of looking at things in a strictly aesthetic sense, the bottom itself becomes a big part of the focus of the aquarium, with the botanicals placed upon the substrate- or, in some cases, becoming the substrate! These materials form an attractive, texturally varied "micro-scape" of their own, creating color, interest, and functions that we are just starting to appreciate.

In fact, I dare say that one of the next "frontiers" in our niche would be an aquarium which is just substrate materials, with minimal, if any, "vertical relief" provide by wood or rocks.

I've been beating that drum for a while now, huh?

I've executed quite a few aquariums based on this idea (specifically, with leaves), and I've been extremely happy with their long-term performance! Oh, and yeah-they kind of looked cool, too...

Nature provides no shortage of habitats with unusual substrate composition for inspiration. If we look at them in context of the surrounding terrestrial ecosystem, there are a lot of possible "functional takeaways" that we as hobbyists can apply to our aquarium work.

And the interesting thing about these features, from an aesthetic standpoint, is that they create an incredibly alluring look with a minimum of "design" required on the hobbyists' part. Remember, you can to put together a substrate with a perfect aesthetic mix of colors and textures, but that's about it.

We have to "cede" some of the "work" to Nature at that point!

Once your substrate is in place, Nature takes over and the materials develop that lovely "patina" of biofilms and microbial growth, and start breaking down. Some may be moved about by the grazing activities of resident fishes, or otherwise slowly redistributed around the aquarium. I suppose the degree to which this happens is dependent upon the type of substrate material you utilize.

This is not unlike what occurs in the wild habitats...newly inundated forest floors have a lot of leaf litter, seed pods, etc., and will be quite turbid for some time. If you understand the context for which they are intended, and the habitats which they help to replicate, this is perfectly acceptable and logical...Of course, you need to make that "mental shift", right?

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

Let's keep on this stuff.

Let's keep questioning aquarium hobby dogma, but let's not become dogmatic ourselves. Let's call out shoddy work and b.s. when we see it, but not to the point of stifling anyone. Let the manufacturers know they should up their game (that includes me, too..)

And, if we're off on our assertions, let's figure out why, and see just what is actually happening in our tanks. If you haven't; figure this out by now, the whole world of botanical method aquariums is, in actuality, one big, grand experiment- and everyone is invited to play!

That means YOU!

Stay creative. Stay excited. Stay motivated. Stay curious. Stay unique. Stay observant. Stay diligent...

And Stay Wet.


Scott Fellman

Tannin Aquatics  


June 07, 2022


Leaves. Yet again.

One of the more satisfying things about working with the botanical aquarium method "movement" is that, over the years, we've seen our thoughts evolve from fringe ideas to interesting experiments to "best practices" as more and more hobbyists began to try them for themselves.

Pretty much the "foundational" piece to our methodology has been to employ leaves into our aquariums. We've been talking about this for 7 years now, and although it seems like a long time, not only weren't we the first people to suggest adding leaves to aquariums. I do, however, think that we were at least among the first to suggest that leaves be added to aquariums not simply to "tint the water" or "lower the pH", but to create a functional substrate which fosters a microbiome of organisms to support the aquarium. Yeah, it's about the function.

Long-held fears and concerns, such as overwhelming our systems with biological materials, and the overall "look" of decomposing leaves and botanicals in our tanks, have understandably led to this idea being relegated to "sideshow status" for many years. It's only been recently that we've started looking at them more objectively as ecological niches worth replicating in aquariums.

Yet, to this day, we see  a lot of social media posts by both hobbyists (and distressingly) by some aquatic vendors/manufacturers waxing on about the aesthetics of adding leaves to your tank, and how they can create a "natural look." Yes, I cringe a bit when I see this- but don't get me wrong- adding leaves to your aquarium does create a cool "look". And it's pretty "natural", for sure!

However, to merely proffer adding leaves to your tank for their visual sexiness overlooks the amazing ecological benefits they provide. And, often these suggestions fail to mention the fact that, even if you want leaves in your tank just for the look- they WILL have some impact on the environment within it. And there are implications about how we manage aquariums with leaf litter present.

Yet, through it all, there is the irony that the function of the leaves creates an even sexier aesthetic- something that we'll touch on later.

So, I think today we'll focus on some of those functional and practical aspects of using leaves in your aquarium again today. 

I suppose that there are occasional smirks and giggles from some corners of the hobby when they initially see our tanks, with some thinking, "Really? They toss in a few leaves and they think that the resulting sloppiness is "natural", or some evolved aquascaping technique or something?"

Funny thing is that, in reality, it IS a sort of evolution, isn't it?

I mean, sure, on the surface, this doesn't seem like much: "Toss botanical materials in aquariums. See what happens." It's not like no one ever did this before. And to make it seem more complicated than it is- to develop or quantify "technique" for it (a true act of human nature, I suppose) is probably a bit humorous. 

On the other hand, as I just mentioned it's not just to create a cool-looking tank, or one which requires "less maintenance." We don't embrace the aesthetic of dark water,  a bottom covered in decomposing leaves, and the appearance of biofilms and algae on driftwood because it allows us to be more "relaxed" in the care of our tanks.

I mean, we are doing this for a reason: To create more natural-functioning aquatic displays for our fishes, which just happen to look different (and attractive!) as well. To understand and acknowledge  that our fishes and their very existence is influenced by the habitats in which they have evolved. 

Wild tropical aquatic habitats are influenced greatly by the surrounding geography and flora of their region, which in turn, have considerable influence upon the population of fishes which inhabit them, and their life cycle. The simple fact of the matter is, when we add leaves and other botanical materials to an aquarium and accept what occurs as a result-regardless of wether our intent is just to create a different aesthetic, or perhaps something more- we are to a very real extent actually replicating  the processes and influences that occur in wild aquatic habitats in Nature!

The presence of botanical materials such as leaves in these aquatic habitats is fundamental.


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

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

The implication here?

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

In Nature, leaf litter zones comprise one of the richest and most diverse biotopes in the tropical aquatic ecosystem, yet they are seldom replicated in the aquarium. I think this has been due, in large part- to the lack of continuous availability of products for the hobbyist to work with, and a real understanding about what this biotope is all about- not to mention, the understanding of the practicality of creating one in the aquarium.

Fast-forward a few years, and many of us are playing with the idea of incorporating leaf litter into our tanks- something that was given little more than a passing bit of attention a few years ago, if that.  This increased level of attention to this environmental niche among hobbyists is reaping benefits for those who have played with it.

Leaves are sort of the "gateway drug", if you will, into our world.


And it is a different world now. 

We are collectively looking more seriously at the wild aquatic habitats from which our fishes come, and how they influence their lives and well-being. Looking at these habitats not only as something we'd like to replicate the look of in our aquariums, but the function- is a big evolution in the aquarium hobby, IMHO.

In the properly-constructed and managed botanical-method aquarium, I believe that leaf litter certainly performs a similar role in helping to sequester these materials. This is an exciting field of study for our community!

Back to Nature for a second. What happens when a leaf falls into the water?

At some point, the leaves of deciduous trees (trees which shed leaves annually) stop photosynthesizing in their structures, and other metabolic processes within the leaves themselves begin to shut down, which triggers a process in which the leaves essentially “pass off” valuable nitrogen and other compounds to storage tissues throughout the tree for utilization. Ultimately, the dying leaves “seal” themselves off from the tree with a layer of spongy tissue at the base of the stalk, and the dry skeleton falls off the tree. 


As we know by now, when these leaves fall into the water, or are immersed following the seasonal rains, they form a valuable substrate for fungi to break down the remaining intact leaf structures. And the fungi population helps contribute to the bacterial population which creates the now-famous biofilms, which consist of sugars, vitamins, and various proteins which many fishes in both their juvenile and adult phases utilize for supplemental nutrition.

And of course, as the fishes eliminate their waste in metabolic products, this contributes further to the aquatic food chain. And yeah, it all starts with a dried up leaf!




Interesting semi-anecdotal observations from my friends in the know, suggest that the biofilms for decaying leaves form a valuable secondary food for the fry of fishes such as Discus, Uaru, (after they’re done feeding on their parent’s exuded slime coat) and even Loricariid catfishes. And of course, all sorts of other grazing fishes, like some characins and even Cyprinids, can derive some nutrition from the fungi, bacteria, and small crustaceans which live in, on, and among the leaf litter bed.

I’ve seen fishes such as Pencilfish (specifically, but not limited to N. marginatus ) spend large amounts of time during the day picking at leaf litter and the surfaces of decomposing botanicals, and maintaining girth during periods when I’ve been traveling or what not, which leads me to believe they are deriving at least part of their nutrition from the leaf litter/botanical bed in the aquarium.


In the aquarium, much like in the natural habitat, the layer of decomposing leaves and botanical matter, colonized by so many organisms, ranging from bacteria to macro invertebrates and insects, is a prime spot for fishes! The most common fishes associated with leaf litter in the wild are species of characins, catfishes and electric knife fishes, followed by our buddies the Cichlids (particularly Apistogramma, Crenicichla,  and Mesonauta species)! Some species of RIvulus killies are also commonly associated with leaf litter zones, even though they are primarily top-dwelling fishes. 

Leaf litter beds are so important for fishes, as they become a refuge for fish providing shelter and food from associated invertebrates!


The preparation of leaves is one of the few "controversies" in the botanical method aquarium world.

Why, Scott? Why do we boil this stuff?

Well, to begin with, consider that boiling water is used as a method of making water potable by killing microbes that may be present. Most nasty microbes "check out" at temperatures greater than 60 °C (140 °F). For a high percentage of microbes, if water is maintained at 70 °C (158 °F) for ten minutes, many organisms are killed, but some are more resistant to heat and require one minute at the boiling point of water. (FYI the boiling point of water is 100 °C, or 212 °F)...But for the most part, most of the nasty bacteria that we don't want in either our tanks or our stomachs are eliminated by this simple process.

Ten minutes of boiling is "golden", IMHO. Of course, we boil for other reasons, as we'll touch on in a bit.

For one reason, we boil leaves and botanicals to kill any possible microorganisms which might be present on them. Leaves have been exposed to rain and dust and all sorts of things in the natural environment which, in the confines of an aquarium, could  introduce unwanted organisms and contribute to the degradation of the water quality.

The surfaces and textures of many leaves lend themselves to retaining dirt, soot, dust, and other atmospheric pollutants that, although likely harmless in the grand scheme of things, are not stuff you want to start our with in your tank.

So, we give all of our stuff a good rinse.

Then we boil.

Boiling also serves to soften leaves and botanicals.

If you remember your high school Botany, leaves, for example, are surprisingly complex structures, with multiple layers designed to reject pollutants, facilitate gas exchange, drive photosynthesis, and store sugars for the benefit of the plant on which they're found. As such, it's important to get them to release some of the materials which might be bund up in the epidermis (outer layers) of the leaf.  As we get deeper into the structure of a leaf, we find the mesophyll, a layer of tissue in which much of photosynthesis takes place.



We use only dried leaves in our botanical method aquariums, because these leaves from deciduous trees, which naturally fall off the trees in seasons of inclement weather, have lost most of their chlorophyll and sugars contained within the leaf structures. This is important, because having these compounds present, as in living leaves, contributes excessively to the bioload of the aquarium when submerged...

And I like to steep the leaves for a bit, too.


I don't think so, but that's just me.

The steep will help break down the tissues a bit to facilitate sinking, eliminate any surface contaminants, and help release some of the remaining sugars and initial tannins bound up in the leaf tissue. Of course, everyone asks if you're eliminating all of the beneficial tannins when you do this.

My answer: No. You re not. They will keep leaching out tannins for quite some time, even after this comprehensive prep process.

Everyone has a different opinion on this; that's just mine. Lately, I admit I've forgone the boiling water in favor of a room-temperature overnight soak, or sometimes, just a heavy rinse in tap water, and then added the leaves to my aquariums. I've encountered no problems, other than a slightly higher "buoyancy" with the non-steeped leaves.

Some people might say they last longer, too. Your call. In the interest of providing the most conservative advice for the greatest majority of hobbyists, I stand by my recommendations to employ some form of prep, as outlined here.

As far as "placement" and "depth of litter bed" is concerned, that's really up to you. I've gone over the possible issues with adding a proportionately large influx of fresh leaves and botanicals to an established aquarium at once, and I stand by my recommendation to go slowly.

As you are aware, rapidly adding a bunch of leaves to an established tank will contribute to the bioload of the aquarium, not to mention, potentially decrease the pH, Increase the CO2, and can have some serious consequences for the animals in your system.

Besides, part of the fun is watching the aquarium "evolve" over time. Test pH, ammonia, and nitrite regularly during the first few days after you've added the botanicals to an existing tank, and perhaps pH and nitrate/phosphate on the longer term, to establish "baseline" parameters and monitor any trends as your system matures. "Test, then tweak" is a favorite old aquarium adage of mine for a good reason.


Depth-wise, it's your call, and wide open for experimentation. In a properly filtered, well-maintained aquarium, I see little reason why you couldn't create a very deep litter bed, approaching 8-10 inches (20.32-25.4 cm) deep- or more! In nature, leaf litter beds may be several meters deep!

Now, I realize that an aquarium is not an open-system like a stream, and that there are upper limits to what you can do, so the real takeaway here is that, with careful experimentation, observation, and a willingness to make "mid-course corrections", you as the hobbyist can try all sorts of things with regards to depth and composition of your leaf litter bed.

And of course, leaves decompose.

And my recommendation is always to leave them "in play" until they completely decompose.

Ahh, decomposition. It goes hand-in-hand with the application of leaves in aquariums...Let's ping-pong back to the wild for a second to talk about this.

Decomposition is an amazing process by which Nature processes materials for use by the greater ecosystem. It's the first part of the recycling of nutrients that were used by the plant from which the botanical material came from. When  botanical material decays, it is broken down and converted into more simple organic forms, which become food for all kinds of organisms at the base of the ecosystem.

In aquatic ecosystems, much of the initial breakdown of botanical materials is conducted by detritivores- specifically, fishes, aquatic insects and invertebrates, which serve to begin the process by feeding upon the tissues of the seed pod or leaf, while other species utilize the "waste products" which are produced during this process for their nutrition.

In these habitats, such as streams and flooded forests, a variety of species work in tandem with each other, with various organisms carrying out different stages of the decomposition process.

Interestingly, in some wild aquatic habitats, such as the famous Peat swamps of Southeast Asia, the decomposition of leaves which fall into these waters is remarkably slow. In fact, ecologists have observed that the leaves typically do not break down.


It's commonly believed that these low nutrient waters, which are high in tannins, and highly acidic, seem to impede microbial activity. This is seemingly at odds with the understanding that passive leaching of dissolved organic compounds (DOC) from leaf litter has been found to be a major source of energy in tropical stream habitats, fueling the microbial food chains which we are so fascinated by.

No doubt the water parameters have something to do with this. These are unique habitats. Here are a few stats from the peat swamps in which some studies on leaf decomposition were conducted:

Water temperature: 25C/77F-32C/89F

pH: 2.6-3.8

TDS: 89-134mg/l

Nitrate: <0.-0.2mg/l

Dissolved oxygen: 1.8-16mg/l

In the studies, leaves of native species  found along the swamps submerged in the waters of the swamps lost very little biomass, which other leaves from trees did break down more substantially. This tends to rule out the generally-held theory that ecologists have which postulates that the slow decomposition rate in the peat swamps is due to the extreme conditions. Rather, as mentioned above, it's believed that the resistance to decomposition is due to the physical and chemical properties of the leaves which are found right along the swamps.

 (image by Marcel Silvius)

The reason? Well, think about it.

Leaf litter in tropical peat swamp forests builds up into peat many feet deep over thousands of years, and thus impedes nutrient cycling. And when you think about it, inputs of nutrients into most peat swamps come solely from rainfall, because rivers and streams in the region don't always flow into the swamps. In such nutrient poor, highly acidic conditions, it is more beneficial for plants to protect their leaves, rather than to replace them when subjected to elements like wind, and herbivore damage (mostly by insects) with new growth.

And interestingly, bacteria and fungi are known to be responsible for leaf breakdown in the peat swamps, because ecologists typically don't encounter aquatic invertebrates in the peat swamp which are known to ingest leaf material!

Our friends, the fungi!

Yeah, those guys again.

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

Here's a fascinating conclusion from a study by researchers Catherine M. Yule and Lalita N. Gomez on leaching of dissolved organic carbon (DOC) in the early stages of the leaf litter decomposition in these peat swamps:

"Most of the DOC appears to be leached within a few weeks of leaves falling into the swamp and thus it appears likely that the cycling of DOC is rapid, and occurs before the leaves become part of the peat deposits. This would further explain the presence of the thick, superficial root mat layer (also a response to waterlogging) that is a key feature of tropical peat forests, since the processes of nutrient cycling would occur in the upper leaf litter layer, rather than the deeper, waterlogged peat."

Okay, neat stuff. It kind of reminds me of those "bog mummies" from Europe, in which the ancient remains s of humans are very well preserved because of the acidic, oxygen-poor conditions of these bogs where the bodies are found.

During the wet season, the peat swamps are inundated with water, which slows down the aerobic decomposition which occurs in the substrate- conditions which facilitate the formation of peat. The breakdown of leaves in the wild is fascinating, as are the implications for the process in our aquariums.

This is a dynamic, fascinating process- part of why we find the idea of a natural, botanical-style system so compelling. Many of the organisms- from microbes to micro crustaceans to fungi- are almost never seen except by the most observant and keen-eyed hobbyist...but they're there- doing what they've done for eons. They work slowly and methodically over weeks and months, converting the botanical material into forms that are more readily assimilated by themselves and other aquatic organisms.

The real cycle of life!

And another reason why the surrounding tropical forests are so vital to life. The allochthonous leaf material from the riparian zone (ie; from the trees!) as a source of energy for stream invertebrates, insects  and fishes can't be understated! When we preserve the rain forests and their surrounding terrestrial habitats, we're also preserving the aquatic life forms which are found there when the waters return.

In our aquariums, we're just beginning to appreciate the real benefits of using leaves and botanicals. Not just for cool aesthetics or to "tint" the water- but to create truly natural, ecologically stable aquatic systems for the health and well-being of the fishes we love so much!

There's a whole lot there to unpack about leaves in the aquairum- drawing from a variety of scientific fields, such as biology, chemistry, and ecology, as well as from our everyday practices as aquarists.

The next time you see a social media post by an "authority" or a brand waxing on about how cool and natural leaves look as aquascaping "props" in an aquarium, just remind yourself that there is so much more to them than that. Don't sell yourself- or the idea- short by touting only the "look."

Studying the influences of leaves on aquatic environments, and how to replicate and incorporate these influences into our aquariums is the key. Building a specialized aquatic microcosm in our tanks will unlock so many secrets and lead to amazing breakthroughs with our fishes- and a greater understanding of the precious natural habitats from which they come.

Stay curious. Stay resourceful. Stay diligent. Stay informed...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


June 02, 2022


Twigs and tangles..

When we first started Tannin Aquatics, the goal was to offer all sorts of useful natural products, with the intention of creating a selection of materials which impact the aquairum environment in many different ways. 

One of the fun things about the botanical method aquarium is that, to a certain extent, it's "anything goes" in terms of materials that you can use to represent the wild habitats. I mean, when you think about flooded forest floors and rainforest streams, you're talking about an aggregation of material from the forest that has accumulated via wind, rain, and current.

This is a remarkable and fascinating habit to replicate in the aquarium. As opposed to a more "contrived" 'scape, with a carefully selected piece or pieces of of driftwood, what I'm framing out here is a more simple, less "placement-oriented", and far more natural-looking 'scape.

I mean, sure, you could certainly use some aesthetic thought in the concept, but when you're trying to recreate what in nature is a more-or-less random thing, you probably don't want to dwell too much on the concept! Rather, put your effort into selecting good-looking materials with which to do the job.

Thats where we come in.

(Yeah, you knew I was going to get there somehow, right?)

We have aggregated (pun sort of intended) a nice selection of interesting twigs, branches, and tangles (as I like to call smaller stuff) with which to accomplish this. The beautiful thing about this idea is that you don't necessarily have to use 12 different varieties of branches and such to create a remarkably complex and interesting scape.


It's not just about then aesthetic, of course. The idea is that you're creating a matrix of these materials to impart a very natural and interesting look to the aquarium. These aggregations provide fishes with hiding places, foraging areas, and spawning sites, just like they do in Nature.

We're talking mainly about twigs and roots...nto big branches here. 

Now, such root/branch tangles DO take up some physical space in the confines of the aquarium, and you need to take this into account when stocking, equipping, and maintaining such systems. Access, water capacity, and filter intakes/outputs need to be considered when you move in a project like this...but that's half the fun, anyways- right?

At the end of the day, the use of twigs, roots, and branches, the organisms which take advantage of them is one of the most stunning aspects of Nature that we can  see in our own aquariums, provided we don't "edit" them out of our tanks.

Like any dynamic habitat, the "twig and root" microhabitat relies on a variety of organisms to do the job of processing nutrients. A diverse assemblage of organisms dwelling in this layer, ranging from bacteria to fungi, to worms and small crustaceans- comprise what we call the "infauna." Essentially, the infauna is a collective of organisms which do most of the work in keeping a botanical-style aquarium functional and healthy.

Be kind to these organisms, and they'll no doubt be kind to you, too! THAT is what the big talk over twigs is all about!

Stay innovative. Stay observant. Stay engaged. Stay curious...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

And of course, you could always incorporate a layer of leaf litter, which really seems to go perfectly with this type of niche. In nature, we see leaves and other materials accumulate in these root tangles and aggregations of fallen branches, so recreating this in nature is kind of a "no brainer!" 

When assembled in conjunction with a nice aggregation of leaves, this configuration  provides a remarkably interesting aquarium with a different sort of aesthetic. 

And the nice thing about utilizing tangled branches in an aquascape, as opposed to  a more traditional  "wood-centric" 'scape, is that you can end up with something that is incredibly realistic and functional. 

And you get some advantages. Case in point?

The potential to keep little groups of fishes, (like my beloved Checkerboard cichlids) behaving naturally in the same tank. Now, I'm no cichlid expert, but I do have a certain love for keeping little "communities" of fishes like Checkerboards together. Oh, and what about Darter characins? Fishes like that? Lots of possibilities, huh?

Perhaps the most interesting aspect of such an aquascaping configuration is to foster natural behaviors and spawning activities among the resident fishes. I would imagine that for "uncontrolled" breeding of many species, the dense matrix of twigs and leaves would create a very good environment for this!

May 23, 2022


The power of Aquatic "Cross Training"

As you know (or maybe you don't!), I spent a good part of the last couple of decades in my hobby and business careers "embedded" in the reef aquarium world. Although I kept freshwater fish during that time, my main focus was everything "reef": Corals, inverts, fishes, systems, etc. I never took my feet out of the freshwater side, but it wasn't until I started Tannin in 2015 that I fell back in, full time, with my "first love"- freshwater!

And, like many of you who have "crossover" experience and skills, I realized that the decades honed in the rapidly evolving reef world gave me the "tools" I needed to "play" in the area of specialized freshwater aquariums. And, as you may or may not have surmised, my lifelong freshwater experience helped me find my way in the frenetic pace of the reef world. 

I have what I like to call  "aquatic cross training."

It's not that unusual, though...a great many of you do, too.

The more our customer base at Tannin grows and evolves, the more I see we're pulling in aquatic hobbyists from other disciplines, including reef tanks, frogs and herps, and planted tank people. I like to see Tannin's community as a sort of "melting pot", where ideas and influences from throughout the aquatic hobby-and around the world- are studied, considered, interpreted, and incorporated into our practice of blackwater and brackish botanical-method aquariums.

However, it wasn't always this way...It wasn't all that long ago that you could sense a real palpable division between freshwater and saltwater "culture" and practice. There was, in the words of many, a strange sort of elitism emanating from the saltwater side (particularly in the reef-keeping world), where freshwater was absurdly looked at by some snobs as "a beginner's world", or an "old person's game",  filled with brown fishes, cluttered fish rooms with disparate equipment, outdated thinking, and lack of progression.

I'd hear it at conferences and clubs all over the world, when I'd come to speak and get to visit the home of an accomplished reefer and see his aquarium, only to find out that he/she "used to keep Discus"- or whatever- and then they'd sheepishly show me their freshwater  tank, as if it were somehow a mark against their skill and honor or something. Weird. I hated that.

It's changed a lot now, which we'll get to soon.

And of course, the freshwater world, at least the people I was in contact with, had an equal amount of skepticism about the "snobby reefers." It was weird, too. And somehow, the myth was perpetuated that, in order to run a successful reef aquarium, you required some incredible skill set and mysterious knowledge, and a bottomless pocketbook in order to succeed.

It was ridiculous, really.  (of course, having a bottomless pocketbook IS kind of helpful, lol) Having long been a "straddler" of both freshwater and reef tanks, I would often challenge "snobby reef types" to set up and manage a full-on planted aquarium, Discus tank, African Rift Lake cichlid tank...or my fave...blackwater!

Fast forward few years...

Things are evolving rapidly on both sides of the "salinity line", new ideas are being expressed, and information exchange is coming at a rapid pace. More and more aquarists are doing both.

And an interesting thing that I've observed...and talked about at the last couple of reef clubs I spoke at": Historically, the aquairum hobby seems to go in cycles, where, in one world (reefing, for example), there might be a period of incredible innovation and progression, while the other side could be more "stagnant" at the  same moment, particularly from a "technique" standpoint.

The pendulum swings back and forth...Curiously, however, both hobbies seem to have reached a similar point at the same time. 

On a popular, mainstream level, in the reef world, the emphasis seems to be on collection of the rarest, most expensive corals and showing over-the-top "'Gram-worthy" tanks on social media.   It's EXACTLY what's been happening in the freshwater world. Many "hobbyists" seem to have forgotten the basics and the real joys and challenges of keeping freshwater and reef tanks, casting aside in pursuit of social media "influencer" status or YouTube fame. In a broad swath of the hobby, the space is filled by relatively inexperienced hobbyists, more eager to garner "likes" and followers than to share knowledge or discuss more fundamental, important  concepts, let alone, learn them for themselves. 

I'm being harsh, I know. That's the way I see it, and I know that this position won't make me popular in all areas of the aquarium world, but I believe that on a "macro level", it's true. In the reef world, very few reefers seem to be trying "new" stuff that doesn't involve a trendy "named coral" or expensive high-tech gadget. In the freshwater side, everyone seems all too happy to replicate someone else's award-winning aquascape, or to feature the latest new wood or rock. Even some brands are falling into this "vapidity trap."

Technique and mastery of fundamental concepts seem to be on the back burner in many areas of the aquarium world (at least, those that come across the loudest to the overall aquarium hobby), in favor of complex reef gear, "named" corals, sterile-looking macroalage tanks, reproducing the most "Amano-esque" aquascapes,  and overall trend-chasing ("negative space aquascape"- WTF is THAT?)...sad.

Look, I get it. Who am I to judge how YOU enjoy your hobby? 

All I know is that I'm about to start my first reef aquarium (ahem, a coral aquarium, really) in almost 10 years, and I'm gonna have FUN doing it! I'm humbly re-indoctrinating myself to the reef side of the hobby, laughing at my own foibles and now-meager knowledge. I'm going to share my experiences, focus on the technique, the learning, the mistakes, and the joys of keeping a reef tank. Sure, I'll be using some new, high tech gear- but it's for the purpose of keeping my corals in good health and growing them to their maximum potential- NOT just to collect Bluetooth-enabled gadgets!

But, yeah, I do have a certain confidence that you can get when you know you can execute well in the hobby. A confidence that has come from being well-rounded, humble, and eager to learn more. A confidence which comes from the ability to evaluate and understand the needs of your animals, and how to address them. A confidence from acknowledging that it's okay to admit that you DON'T know everything, and that you might just screw up...

Getting back into reefing will be incredible: Challenging, interesting, and growthful.

Yeah, this is where my "cross training" will serve me well.

The same fun experimentation, focus on the basics, and love of the "craft" which I apply to my botanical method aquariums will be installed into my reef tank. Sure, the equipment is different- the animals are different...indeed, my focus will be different- but the idea is the same: To provide conditions for the optimal health and growth of the organisms I care for.



And of course, all of this desire to learn and share comes with a dark side, too. 

Even with all of the wonderful possibilities of learning and experiencing both sides of the salinity line, so many people are falling into a trap. A trap which dumbs down the hobby on both sides by focusing on the most superficial aspects of stuff, and seems to keep people stuck in weird places.

When I see the hobby being affected by close-mindedness and tainted by hype and consumerism over technique and progression, I have to open my big mouth. Love your crazy corals. Love your brown fishes like I do. But learn about them in ways you haven't before. Grow a little. Share what you know- not just what you HAVE. Understand that there is more to a hobby than just acquiring stuff and trying to impress people with your material wealth. "Bling" is not talent, and doesn't help you nor the hobby progress, survive and prosper long term.

And, to would be "influencers" and "brand ambassadors": Many of you simply suck. Period. Your days are numbered, IMHO. Eventually, people are going to start realizing that you're not offering up anything of value. And your "sponsors" will notice, too. It's a matter of time. Get your shit together...Do something of substance. Simply trying to game the social media platforms for the sake of acquiring a "sponsorship" - making a "career" without actually bringing anything of substance to the table besides cute production and video editing skills is the biggest joke in the hobby, IMHO.

I can't believe that the smart people at many hobby brands just don't seem to realize that a high percentage of the people they're signing up as "brand ambassadors" are a bunch of shallow idiots who don't know shit about the hobby.  Ouch! "Damn, Fellman said the quiet part out loud!" Yeah, I did...because the hobby doesn't need more flashy vapid, cleverly-produced videos about NOTHING, with a token product shot, to get people educated and interested.

It doesn't. That's not how to get- and keep- people in the hobby for the long term. How this has even become a "thing" is almost beyond my ability to comprehend. And I'm not just some grumpy old guy.  (at least, I don't think so, lol). If you look at it more objectively than I just did in my "analysis" (not hard to do THAT!), I think you might actually agree with my thinking (but probably not the tone, lol)!

Do better, guys.

Think about how much more we would all benefit if hobbyists emphasize technique, and share just how you keep these amazing animals alive long-term, and reproduce them. Sharing the good, the bad, and all of the "boring" stuff in between (hint: it's NOT boring!)  It's being done in many areas already by a few really great people- but that's not what the majority of the aquarium world sees. They see the stupid crap on social media- cause there is too damn much of it.

This is just my opinion, of course...

Whew...rant over. For now. 

Back to the "cross training" part...

Progression is really important, and easy to share. And surprisingly easy to "import" from other parts of the hobby.

Playing with natural materials or planted aquariums is a prime "training ground" for venturing into the reef world, IMHO. Because you're getting used to the idea of creating and managing a miniature ecosystem, and learning about the complex relationships between various aquatic organisms.

In our own community, not a day goes by when we don't receive a pm or email from an aquarist somewhere in the world showing us a progressive new botanical method aquarium, or sharing one they've had set up for years...

And with more and more discussion on brackish-water aquariums and a fresh approach, I think we'll see even more aquarists showing an interest and elevating yet another niche in the freshwater hobby...bridging the "salinity gap" and emphasizing a collaborative, ultra inclusive mindset, way of thinking, and..."culture" that we hope will continue to set the standard for the way a global community within the aquarium world should be.

No elitism. No snobbishness. No exclusivity. 

Just fun. And learning...

Learn from each other...

If you're a lifelong freshwater hobbyist, just go for it and apply your skill set to a reef tank. You'll realize at once all of the cool stuff you bring to the table. If you're a hardcore reefer (and I know some of you do follow my stuff, because you tell me you do...), lower your guard just a bit, expand your thinking and skills and try a specialized freshwater system and bring YOUR set of talents along.

The potential breakthroughs from this "cross-pollination" are incredible.

Among progressive and talented reefers- which there are many- some are looking for new approaches. Some have confided in me that they miss the challenges of progressive work. They need to apply this thought to reef keeping, before it simply turns into a "frag fest" of overpriced, overhyped coral selling as a hobby. Or a soulless, tech-focused affair, with the "living organisms" part relegated to an afterthought. Some get it. And many of them have crossed back over into freshwater,  or tried it for the first time...with the emerging popularity of niche movements like...blackwater, etc.

And their reef work is better than ever- I belive because they are applying those hard-won skills to a new "medium"- growth is constant.  

I'm sort of happy to fill my role as a fish culture "ambassador" between the two sides of the "salinity line." I have a number of friends who see specialty freshwater systems (like our blackwater/botnaical-style tanks) as a sort of analog to reefs, where interactions between the fishes and the overall environment are an important part of the equation, and they're excited about trying one.

If they bring the best aspects of reef keeping (rapid iterations, system design/construction, experimentalism, understanding the relationship between organisms), and leave out the "Super-duper named high-end coral frag" bullshit- we may just have something here.

In fact, I think we already do.  

So, if your a bit dismayed with whatever side of the fence your on, do more than just a causal foray into that other side"- it not only will make you a better hobbyist- might just re-ignite your passion you might have been missing.

THAT is the ultimate benefit of "aquatic cross training!"

Stay engaged. Stay interested. Stay passionate. Stay curious. Stay diligent...

And Stay Wet.


Scott Fellman

Tannin Aquatics 





May 20, 2022


The whole picture...

One of the interesting things about creating a botanical method aquarium is that it's really easy to get "into the weeds" about the ecology and the environmental aspects of the tank, almost at the exclusion of everything else. We tend to emphasize the function of the ecosystem that we are developing over almost all else. And sometimes, I admit, that can be a bit short-sided. 

Sometimes, it's important for me as a self-proclaimed "thought leader" in this space to delve into the more practical, everyday, or even mundane aspects of their management. Let's talk about a few of these things today, in no particular order...


For all of the hobbyists who have simply come to expect that the water in their tanks will typically never be crystal clear, we still receive a fair number of questions asking if it's "normal" for the water to have a slight "hazy" look to it (in addition to the color, of course).

The water is almost never perfectly crystal clear in our botanical method aquariums. The clarity of the water in our aquariums is directly related to the physical dissolution of "stuff" in the water, and is influenced-and mitigated by- a wide-range of factors. Turbidity ( defined as "..the quality of being cloudy, opaque, or thick with suspended matter") is completely normal and common in the botanical method aquarium.

I won't disagree that "crystal-clear" water is nice. I like it, too...However, I would make the case that "crystal-clear" water is: a) not always solely indicative of "healthy" or "optimum" , and b) not always what fishes encounter in Nature. 

Habitats such as flooded forests are almost never crystal clear. The large quantity of soil, sediments, and decomposing vegetation that is present on the forest floor during the dry periods will often create turbid conditions that will linger throughout the phase of inundation.


Botanical materials will impact the clarity of the water as they begin to decompose and impart the lignin, tannins, and other compounds from their physical structure into the water in our aquariums. Also, many of us use alternative substrate materials, consisting of bits of botanicals, sediments, and clays- and these will also have a definite impact on the clarity of the water. There will always be small amounts of this stuff in suspension.

Remember, just because the water in a botanical-influenced aquarium system is brownish, and even slightly hazy, it doesn't mean that it's of low quality, or "dirty", as we're inclined to say. It simply means that tannins, humic and fulvic acids, and other compounds from the botanical materials are leaching into the water, creating a characteristic color and turbidity that some of us geeks find rather attractive. If you're still concerned, monitor the water quality...perform a nitrate or phosphate test; look at the health of your animals.

These factors will tell the true story.

You always need to ask yourself, "What's actually happening in there?"

In almost every case in my experience, chemically, the water has minimally detectable concentrations nitrate and phosphate...biologically"clean" by aquarium standards.

Sure, by municipal drinking water standards, color and clarity are important, and can indicate a number of potential issues...But we're not talking about drinking water here, are we?

I believe that a lot of what we perceive to be "normal" in aquarium keeping is based upon artificial "standards" that we've imposed on ourselves over a century of modern aquarium keeping. Everyone expects water to be as clear and colorless as air, so any deviation from this "norm" is cause for concern among many hobbyists.

It need not be, IMHO.


To your comfort, you'll find that botanical method aquariums are as stable as any other if you follow regular maintenance and good old common sense.

So, what are we talking about, in regards to "regular maintenance?"

Well, for one thing, water exchanges. Yes, the dreaded freakin' water exchanges...Because the topic is so well discussed in the aquarium world,  I'll keep it relatively brief on this topic: 

What’s a good water-exchanging regimen?

I’d love to see you employ 10% per week...It’s what I’ve done for decades, and it’s served me- and my animals- very well! Regardless of how frequently you exchange your water, or how much of it you exchange- just do them consistently. And of course, as previously discussed, don't go crazy siphoning every bit of detritus out during the process.

Remember that, in an aquarium which encourages the growth of bacteria, fungi, copepods, etc., the organic material contained in detritus becomes part of the "food web." And everybody up the food chain can benefit from the stuff.

So, by going "full ham" and siphoning out every last speck of detritus from your tank, you're essentially breaking this chain, and denying organisms at multiple levels the chance to benefit from it! Yeah, over-zealously siphoning this material from your tank effectively destroys an established community of microorganisms which serve to maintain high water quality in the closed environment of an aquarium!

This is a super-important point to remember!

In an ironic twist, I believe that it's far more common for those "anomalous" ammonia spikes and such that aquarists report periodically, to have their origin in over-zealous cleaning of aquariums and filter media, as opposed to the accumulation of detritus itself. So, yeah-taking out all of the "fish shit" is actually removing a complex microbiome that's keeping your tank healthy!

Even something as seemingly "mundane" as the way we maintain our botanical-method aquariums requires us to make some "mental shifts" to appreciate our methodology more thoroughly, doesn't it?


Well, some of it does...It's almost inevitable that some stuff gets shifted around. Leaves and seed pods are pretty lightweight materials, and as they decompose, they're even more lightweight and "mobile."

And that's not necessarily a bad thing. Don't get stressed if you stir some stuff up. Your tank will be fine. Likely, the fishes couldn't care less...

Think about the natural leaf litter beds, and the processes which influence their composition, structure, and resilience. Many litter beds are long-term "static" features in their natural habitats. Almost like reefs in the ocean, actually. Yet, there is a fair amount of material being shifted around constantly by current, rain, flooding, and the activities of fishes.

Yeah, stuff does get disturbed and redistributed.

The organisms which reside in these systems deal with these dynamics effectively. They have for eons.

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 learning (?) to adapt to a changing environment.

And perhaps...maybe...the idea of fishes sort of having to constantly adjust to a changing physical (note I didn't say "chemical") 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...the season has changed, because there's an influx of new water...leaves are rolling around..." Perhaps not as "specific", but something like that, which can trigger 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 to be added to from time to time.

Which leads us to the next, most commonly-asked question about maintaining botanical method aquairums:


Hell, yes.

Take care of your aquarium- your miniature closed ecosystem-by taking care of the enormous microcosm which supports its form and function. And that means, not removing all of this material as it decomposes. I know, I've said it several times already in this one piece, and countless times in "The Tint" and elsewhere, but it's really a fundamental part of the botanical method of aquarium keeping.

Of course, I realize that the aquarium is a microcosm of Nature, and not an open system. However, in principle, many of the factors which control Nature control our aquariums, too. Some are a bit different in "execution", but the influence is similar. 

I don't do a lot of siphoning of decomposing botanicals from my substrates, which are typically a mish-mash of leaves, twigs, and bits and pieces of botanicals. Sure, you CAN stir up this layer, and simply "swish" a fine meshed net around in the water column, and try to remove anything you find offensive.

I wouldn't get too carried away with it. Other than from an aseptic standpoint, I have a hard time justifying the removal of decomposing botanicals from the aquarium to any great extent. 

What goes down...doesn't always have to come up!

This is not an excuse to develop or accept lax maintenance practices. It's simply a "call to awareness" that there is probably nothing wrong with your system when you see this stuff. It's quite contrary to the way we've been "acculturated" to evaluate the aesthetics of a typical aquarium. You'll have to get used to a certain amount of material decomposing in your tank.

It's perfectly natural, and part of the function of the aquarium...and, in a more superficial sense- part of the aesthetic. Accepting the fact that you'll see decomposing materials, biofilms and fungal growth in your system is something that many aquarists have a very difficult time with.  I get it. Again, it's one of those things that many of us are simply not accustomed to in our aquarium keeping work.

Observe underwater videos and photos of environments such as the Amazonian region, etc. and you'll see that your tank is a much closer aesthetic approximation of nature than almost any other system you've worked with before!

And, to your comfort, you'll find that these systems are as "chemically clean" as any other if you follow regular maintenance and common sense. 

Ultimately, your decision to create a botanical method aquarium is as much a philosophical one as it is a practical one. To accept nature, rather than to fight it, is a bit at odds with the mindset many of us have with regards to aquarium keeping.

As you begin to understand and evaluate your own aquarium, you'll gain a greater appreciation for the wonders of Nature, and the processes that have occurred for eons. And of course, you're going to really appreciate the "whole picture" of seeing your aquarium function and appear much like a natural aquatic ecosystem does.

It's something that's truly transformative in our hobby; something which only those who dare to be different can experience.

Stay Bold. Stay Creative. Stay excited. Stay diligent...

And Stay Wet.


Scott Fellman

Tannin Aquatics 



Your fishes call it "food..."

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

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

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

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

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

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

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

I don't believe that this is mere coincidence.

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

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

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

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


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

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


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

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

Something is there- literally!  

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

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

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

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

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

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

Just like in Nature. 


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


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


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

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

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

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

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

Why not, right? 😆

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

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

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

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

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

We learn to appreciate it by looking to Nature.

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

A priceless natural resource.

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

A true gift from Nature. 

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

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


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

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

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

Yeah, he got it. 

You can, too. 

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

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

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

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

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

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

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

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

And Stay Wet.


Scott Fellman

Tannin Aquatics 

May 14, 2022


The really long game...

As you know, I spend a lot of time talking very critically about the short term mindset that seems to be pervasive in the hobby, seemingly enabled by the frenetic pace of tank "do-overs" in the aquascaping world. I think that it's because we're driven by social media and the need to constantly show new stuff to the world. It's almost obligatory for many.

In addition to finding it a bit sad that hobbyists feel compelled to "churn" a ton of work all the time, I sometimes worry if the art of long-term maintenance- or even the idea of keeping an aquarium set up over the long term- like- years versus, ya know- a few months (or a "contest period!")- is a reality that most newer hobbyists have thought of.

Like, believing that the entire point of the hobby is to continuously setup, break-down, and re-set-up tanks. Never understanding that the real magic with aquariums and fishes is to recreate an ecology- an environment- in the aquarium- and allowing it to emerge and evolve over longer time spans.

Yeah, it's a long game, in my book.

In our botanical method aquarium game, we talk a lot about establishing more natural-functioning/appearing systems, and many of the nuances associated with getting them up and running. However, we seem to spend a relatively small amount of time talking about what actually happens in these tanks over the very long term and how to manage them, right?

With so many hobbyists getting into this style of aquarium for the first time, it's worth another look!

Like every great story, this one starts at...the beginning.

There's nothing quite like a brand new aquarium; one filled with promise and potential. In the botanical-method aquarium, the aquarium looks quite a bit different than it will ultimately appear down the line- the botanicals are clean and untouched by biofilms, the leaves appear crisp and largely intact, and the wood and substrate are typically sharp and free of that "patina" of growth that occurs over time.

Crisp. "Fresh." Clean-looking.

And that's nice, I suppose. I mean, it IS.

Yet, it's not really all that "natural", IMHO.

Sure, it meets the hobby's broadest "expectations" of just how an aquarium should look. At least, from a "neatness" standpoint, right? Many hobbyists- and I'm convinced, many more- would totally embrace the botanical-method aquarium approach  more wholeheartedly if they could keep their systems sort of "frozen" in time at that point.

Many do this, and take great pleasure in the process.

Yet, to many of us, the real "allure" of the botanical-method aquarium is what takes place after those first glistening weeks- the time period when the aquarium starts to evolve, take on an even more natural look, and becomes more of an ecosystem, as opposed to a primarily aesthetic display.

There are some characteristics of these types of tanks which require a fair amount of continued management that keep them functioning effectively-most notably, the continuous addition of more botanical items to replace those which break down, be they leaves, wood, or seed pods and the like- in order to maintain not only the visual "tint", but the beneficial humic substances and other organics contained in these materials. 

Over time, many of these compounds are dissolved into the water column, and these botanical materials will no doubt lose some of their efficacy as "environmental enhancers."

And obviously, this sort of "active management" not only creates a more stable environment for your fishes, it provides an opportunity to continuously engage with your aquatic environment on a very regular basis. Continuously replacing and adding more botanical materials over time  is one of the most important aspects of managing this type of aquarium, and is especially critical in an environment in which the very structure of the ecosystem itself evolves and changes over time!

Now, unlike other tanks I've managed over the years, such as reef aquariums, planted tanks, etc., where you need to sort of change or evolve your husbandry tasks as the tank ages (i.e.; pruning, revising fertilization schemes, etc.), the botanical-method natural aquarium seems to benefit from the same types of maintenance tasks throughout its functional lifetime.

Some hobbyists choose to let their botanical items remain in the system until fully decomposed; others prefer to remove items just as soon as they lose the "pristine show look." Regardless of how you handle the "botanical breakdown", you're more-or-less following the same practices over a long term. 

Consistency. Our old friend.

And of course, water exchanges are as important a part of the management of our systems as any other. The dissolution of organics and "reset" that water exchanges provide are one of the "cornerstone" practices in aquarium husbandry, and will help continuously hold your environmental parameters. 

As any aquarium ages, it's essential to at least have a handle on what is happening chemically. In the botanical-style, natural aquarium, it's nice to conduct basic water parameter tests early on in the tank's existence, to establish a reference "baseline" of the tanks typical "operating parameters".

In a typical tank, you may see a gradual reduction in pH over time.  This may be caused by acids forming from accumulated nitrate and other nitrogenous compounds and over time, as they overwhelm the buffering capacity of the tank. This seems to be much more common in higher pH systems, such as African cichlid tanks, reef aquaria, etc.

You will likely find, as I have, that with the consistent management of your natural-style botanical method aquariums, very little in the way of "parameter shift" appears to occur. I've seldom noticed any sort of appreciable pH decline over time in these tanks (probably because you're starting out with lower pH!), and nitrate and/or phosphate levels tend not to vary significantly at all with consistent botanical replacements and water exchanges.

I'm curious what YOUR experience has been in this respect.

I also tend to monitor TDS a lot in botanical tank. Now, IMHO, TDS is probably the least useful measure that we use in aquarium management, despite the near obsession that some aquarists have about this. I mean, it's not all that useful, because it is literally what its name implies- a measure of total dissolved solids. That could literally be anything, ranging from minerals to KoolAid, for that matter!  It doesn't tell you what, exactly, the dissolved solids are.

It's main importance, iMHO, is when you're measuring the output of your RO/DI unit...it should read zero, or very close to zero.

 Curiously,  I've found that I will see a "range" of 2-3 ppm at the most, in which the parameters seem to stay throughout the lifetime of the tank. Any deviation from this should be something that you should investigate. Not necessarily a "bad" thing, again, as TDS can be just about anything...yet I suppose it best it does function as a sort of "yardstick" for environmental consistency.

Ah..consistency over time again.

One physical maintenance task that I have found to be continuous and necessary with botanical method aquariums is the cleaning of filter intakes, mechanical filter media, and water pumps. With a constantly-decomposing array of botanical materials, biofilms, and fungal threads streaming into the water column, lots of small debris tend to get sucked into filter intakes, pumps, and of course, mechanical filter media. These need to be cleaned/replaced on a regular basis; perhaps even more frequently than other maintenance tasks.

It's simply part of the game when working with a botanical-method aquarium!

Nothing we've mentioned here is earth-shattering or revolutionary, from an aquarium husbandry standpoint. However, seeing that for many hobbyists, this is their first experience at managing a botanical-method blackwater aquarium, and with tons of information out there stressing concepts like breaking down a tank after a few months, I think it's not a bad idea to review this sort of stuff from time to time!

In natural-style aquariums, seldom are big moves or corrections required. Rather, it's really a combination of little things, done consistently over time, which will see your aquarium thrive in the long run. 

Yeah, over time.

The thing that's perhaps most unique about the botanical-method approach is that we tend to accept the idea of decomposing materials accumulating in our systems. We understand that they act, to a certain extent, as "fuel" for the micro and macrofauna which reside in the aquarium. The idea of leaving this material in place over the long-term is a crucial component of this approach, IMHO.

As we've discussed repeatedly, just like in Nature, they'll also form the basis of a  complex "food chain", which includes bacterial biofilms, fungi, and minute crustaceans. Each one of these life forms supporting, to some extent, those above...including our fishes.

So, when you're contemplating and executing your "evolutions" I have long believed that if you decide to let the botanicals remain in your aquarium to break down and decompose completely, you shouldn't change course by suddenly removing the material all at once...Particularly if you're going to a new version of an existing aquarium.


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

Okay, it's a theory...But I think I might be on to something, maybe? So, like here is my theory in more detail:

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

Just like in natural aquatic ecosystems...

The botanical materials are a real "base" for the little microcosm we create.

And of course, by virtue of the fact that they contain other compounds, like tannins, humic substances, lignin, etc., they also serve to influence the water chemistry of the aquarium, the extent to which is dictated by a number of other things, including the "starting point" of the source water used to fill the tank.


So, in short- I think the presence of botanicals in our aquariums is multi-faceted, highly influential, and of extreme importance for the stability, ecological balance, and efficiency of the tank.

I am a fanatical observer of my aquariums, particularly the botanical-style ones I run (oh, all of them...), and I do the same things over and over and over again; specifically, weekly small water exchanges. I don't overcrowd my tanks. I don't add tons of fishes at one time. I don't overfeed my fishes. I don't add a large batch of botanicals at one time to "remodeled" or existing aquariums. I'm annoyingly patient. I don't freak out over things taking a while.

I embrace "detritus" ( at least the kind that is caused by mineralization of botanical materials) as "fuel" for the biological "operating system"- not as something to be afraid of. 

And, like many of you, I don't see a need to rush to some version of "finished." 

Personally, I don't think that botanical-style aquariums are ever "finished." They simply continue to evolveover extended periods of time, just like the wild habitats that we attempt to replicate in our tanks do...

And the botanicals in the aquarium? Well. they'll keep breaking down, "enriching" the aquarium habitat. Imparting humic substances, lignin, etc. Compounds which have a material impact on the ecology, biology, and chemistry of the aquarium.

Understand and facilitate these natural processes into your aquariums. Keep that in mind when you "iterate" an aquarium.

If you're months into a tank, and simple don't like the look or performance or whatever- you can easily change it. It's a lot like catching a continuously-running commuter train or subway line, right? There's always an opportunity to go somewhere new. You just have to jump on.

Part of the beauty of the botanical-style aquarium is that you can sort of "pick it up where you are" and "ride it" out for a while, or change the "routing" as you desire! Started your tank as an Amazonian habitat but you're suddenly enamored with a more "Asian" look?

Keep the "operating system" intact, but change out some elements. Don't feel compelled to "siphon out all of the detritus" or whatever the B.S. that you hear regurgitated when people talk about tank makeovers. Unless you're tearing apart the tank because it's a smelly, stinky, mismanaged, toxic pile of shit that's killing your fishes, keep the biological "fuel" intact for your new iteration! (and vow to take better care of your tank this time!)

Super easy, right?

It is. If you let it be that way.

Evolution in our aquariums is not only fun to watch, it's a lot of fun to manage as well. And it's even more fun to have the option to do either!

Evolving and managing a botanical method aquarium is really something that we should take to easily. It is actually a pretty effortless process. Setting up an aquarium in this fashion also provides us with the opportunity to literally "operate" our botanical-style aquariums; that is, to manage their evolution over time through deliberate steps and practices.

This is not entirely unknown to us as aquarium hobbyists.

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

Yes, it's an evolution.

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

Earth-shattering? Not likely.

Educational? For sure.

Thought provoking and fun? Absolutely.

Just realize that it's a long game. Not a quick, "instant aquarium" process. 

We can let things decline. Or, we can take charge and attempt to stave off the inevitable. Botanical-method aquariums offer numerous opportunities for making changes- or not.

How we as humans choose to accept this progression and change is purely based on our own tastes.

The reality is that these things will continue despite any interventions we perform on our tanks. We can "resist" them, performing "maintenance" takes on our tanks, like trimming plants, fragging corals, scraping algae, stirring the top layers of substrate, etc.- but these are merely serving to counteract or stave off the inevitable changes that occur in an aquarium as it establishes itself, begins to thrive, and runs at a stable pace for extended periods of time.

Some tanks decline over time.


Of course, in many cases, the "decline" is so gradual, so subtle, that the outsider hardly notices.  In the case fo a botanical-method aquarium, with its abundance of seed pods, leaves, and other materials, you'd be hard-pressed to really call it a "decline." It's more like an evolution, really.

You, the aquarist, ever keen on anything that occurs in your tank, will notice- and often perform subtle (or not-so-subtle) interventions to counteract this process, lest it descend into some sort of chaos, right? 

Yet, isn't "chaos" sort of a human-ascribed thing? I mean, we're talking about changes in the aquatic habitat which evolve the look and perhaps the biological "operating system" of the aquarium. This is absolutely analogous to what happens in natural aquatic systems.

Stuff breaks down, and different types of organisms flourish and reproduce as a result. Nothing goes to waste in Nature...and that includes the "nature" which is found in our aquariums, too..If we allow it to happen.

It's entirely possible, in my humble opinion, that we, as aquarists actually sabotage the essential natural processes which help our tanks run when we attempt to "intervene" through excessive maintenance.

The ebb and flow of life in a natural, botanical-method aquarium is much like a garden. You can and should perform regular maintenance, conducting water exchanges, filter media replacement, etc.- like you do in any other tank. However, you need to conduct these maintenance sessions not with the idea of "THIS will take care of those biofilms", but an attitude of. "This will continue to facilitate change over time..."

Yeah, it requires a certain attitude.

And a willingness to look at Nature as she actually is- and to appreciate the beauty in the details of Her processes.

A willingness to accept.

An acceptance that Nature will plot the right course for your tank. And, you need a degree of patience and yeah-faith- that things will unfold in ways you may not even have begun to appreciate. Like any other aquatic endeavour, you can make it easier and more enjoyable by being aware of what is going on, and accepting the way Nature works Her magic.

It simply takes time.

And patience.

Perhaps a hands-off approach- "passive management", if you will- is not always a bad thing.

I sometimes wonder what our aquariums would evolve into over the course of a couple of years if we merely performed basic maintenance tasks, such as water changes, equipment maintenance, feeding, scraping the viewing panels, etc., and did little else. No animal replacement. No trimming of plants, fragging of corals, or removal of fish fry. No rearranging of the aquascape. 

What would you end up with?

Of course, the answer depends upon what the "end point" is. For that matter- does there have to be one?

It seems that in recent years, I've executed more aquariums in a shorter period of time than ever in my aquatic career. Unusual for me, because, as you might imagine- I'm kind of a "leave the tank be" kind-of-guy.

I'm typically not a fan of big "edits" on my tanks, once they're settled in.

Nature doesn't "edit." She evolves.

Could you resist "editing" your aquarium for a period of time? Would you want to? Is rearranging stuff and re-working things as much part of the hobby as just looking into the tank and enjoying it? 

For some it is.

And if you went completely "hands-off" with your tank, what would happen?

I don't think all that much, in the case of botanical method tanks. I think you have to possess a basic understanding of the environmental processes and conditions within your aquarium. This will give you a lot more confidence in how your tank can evolve and run with minimal intervention. Sure, you might rework the "aquascape" part from time to time, but if you leave the essential biological components of your aquarium more-or-less "intact" for an indefinite period of time, it'll likely just keep on plugging along. This idea of an "eternal aquirium"  is really compelling.

So, what would happen if you went full "hands-off?"

Would anarchy reign, or would a different sort of system ultimately evolve? Would it succeed on some level that you wouldn't have considered previously? What would come to dominate, and what would fade away?

How would Nature work with what you gave her in your little glass or acrylic world called "an aquarium?"

Likely, none of the horrifying outcomes dancing around in our heads would occur. Rather, if left to Her own devices, Nature will find a way to create a consistent ecology.

It's what She's done for eons...She plays a really "long game."

You should, too.

Stay patient. Stay observant. Stay dedicated. Stay confident...

And Stay Wet.


Scott Fellman

Tannin Aquatics