October 29, 2021


Pushing through.

As a lifelong aquarist, I’ve had a lot of good, bad, and awful experiences playing with aquariums. Like many of you, I’ve experienced and endured stuff that pushed the limits of what I thought I could tolerate. Adapting the botanical-style aquarium approach (or the ideas behind it) about 18 years ago was a radical departure from what was know, comfortable, and "easy." It involved adopting a new mindset, creating new comfort levels, and a different approach.

For many years, I was a form believer in the “remove ____________ when it shows up in your tank.” philosophy of aquarium management. Everything had to be scrupulously clean. It makes sense that I'd have this mindset. I was raised in the hobby during the era of "technology and water quality", wherein the doctrine was to essentially scrub out or remove anything which went against the goal of crystal clear water and spotless substrate.

As you know, my mindset has shifted over the years to the point where I'm almost the diametric opposite of that mindset. And, being a philosopher of all things aquatic, I have expended a lot of mental energy over the years trying to figure out why this "doctrine of spotlessness" arose in the first place, and has stuck in the hobby for so long. I mean, I think I figured out why it started: In the mid 20th century, we finally figured out the way to "control" natural processes via a combination of technique and technology...You know, like accumulations of detritus, turbid water, algae, etc.

Think about the late 1950's and 1960's in the aquarium hobby. Filtration technology, pumps, filter media, lighting, etc. all began to evolve and reach prominence. The possibilities were endless for hobbyists. The desire to control Nature and bring a piece of it into our suburban living rooms was irresistible. The "we can do anything!" mindset, which arose out of the space age trickled down into virtually every human endeavor, including aquarium keeping! Why would you want want algae, turbid water, and detritus when this filter will provide you with crystal clear, algae-and-detritus-free water by just plugging the thing in?

And I think that began the desire to control all sorts of parameters in our aquariums; to wrangle control from Nature. The idea of crystal-clear water and spotlessness was a sort of "over-compensation" for almost a century of "being at the mercy of Nature" and not understanding what was occurring in our tanks, and why technology gave us the ability to circumvent the things which represented our  lack of control of Nature.

And this mindset has been pervasive for decades in the hobby. And I think that's evident in many different approaches to aquarium keeping right now. It's pervasive and has impacted the popular perception of what aquariums should be like and look like...

Okay, big lead up there.

My point is this: 

The botanical-method aquarium approach is fundamentally different than what is currently espoused in the hobby. It functions and looks different than virtually any type of aquarium that you'll typically see. There is a completely different set of expectations that goes along with this approach.

And yeah, it can even be seen as a bit of a spiritual journey, too- leading to some form of enlightenment and education about Nature, from a totally unique perspective. This is important to grasp.

The energy, attitude, and creativity that you bring with you on the journey tends to become amplified during the experience. As you work with botanicals in your aquariums, your mind takes you to different places; you let go of old preconceptions about the hobby and embrace new ideas for how your aquarium's microcosm can evolve. Every tank- like every hobbyist- is different- and different inspirations arise. We don’t want everyone walking away feeling the same thing, quite the opposite actually. 

That uniqueness is a large part of the experience.

The experience is largely about discovery. 

Our aquariums evolve, as do the materials within them. We've discussed this concept many times, and it may seem a bit trivial to some, or overly prosaic to others. We keep coming back to this idea because it's a huge part of why our aquariums look and function so differently in the first place.

If we think of an aquarium as we do a natural aquatic ecosystem, it's certainly realistic to assume that some of the materials in the ecosystem will change, re-distribute, or completely decompose over time.

There are many times during the establishment of your aquariums (it applies to a lot of aquarium types, but I'm specifically focusing on the botanical-method aquarium here) when you might be challenged to persevere by what you see happening in your tank. You might have been expecting a perfectly orderly, "Insta-ready" tank from day one. 

Nature had other plans.

Often times, you'll see turbid, tinted water, stringy biofilms, and detritus building up in your tanks.

Your aquarium water may appear turbid at various times. We are pretty comfortable with this idea; however, some of you may not be. As bacteria act to break down botanical materials, they may impart a bit of "cloudiness" into the the water. Also, materials such as lignin and good old terrestrial soils/silt find their way into our tanks at times.


Some of these inputs, such as soils- are intentional! Others are the (unintended) "by-products" of the materials we use. The look is definitely different than what we as aquarists have been indoctrinated to accept as "normal." It gives the water in botanical-method aquariums a certain "texture" or opacity that's hard to describe. One of my good friends, and a botanical-method aquarium freak, calls this phenomenon  "flavor"- and we see it as an ultimate expression of a truly natural-looking aquarium. 

Yeah, the water itself becomes part of the attraction. From a purely aesthetic standpoint, the color, the "texture", and the clarity of the water are as engrossing and fascinating as the materials which affect it. It's something that you either love or simply hate...everyone who ventures into this method of aquarium keeping needs to make their own determination of wether or not they like it. 

Need a bit more convincing to embrace the charm of the water itself in botanical-method aquariums?

Simply look at a natural underwater habitat, such as an igapo or flooded varzea grassland, and see for yourself the allure of these dynamic habitats, and how they're ripe for replication in the aquarium. You'll understand how the terrestrial materials impact the (now) aquatic environment- the function AND the aesthetic-fundamental to the philosophy of the botanical-method aquarium.

Speaking of the impact of terrestrial materials on the aquatic habitat- remember, too, that just like in Nature, if new botanicals are added into the aquarium as others break down, you'll have more-or-less continuous influx of materials to help provide environmental continuity- or "enrichment"- to the aquarium environment. This type of "renewal" creates a very dynamic, ever-changing physical environment, while helping keep water chemistry fluctuations to a minimum.

The addition of new materials into the aquarium  is the perfect analog to the concept of "allochthonous input" which occurs in wild aquatic habitats- materials from outside the aquatic environment- such as the surrounding forest- entering and influencing the aquatic environment.

Take these discoveries into the aquarium, and you have something very different than what we've embraced as a hobby for generations.

For many years, playing with this idea was considered a"problem." We had well-founded fears about the process, the look, and the management of these types of aquariums, based on generations of established ideas and techniques that told us this was contrary to proper aquarium practice.

A "problem."

I think that the "problem" of botanical-method/blackwater tanks for years was that we saw them as "dirty", dangerous", "non-sustainable" etc. We didn't look at the blackwater environment as one that required that we meet a specific set of parameters.

We didn't look at keeping botanical-method/blackwater aquariums as an endeavor that required an understanding of the processes involved, and developing technique and practices to accomplish our goals. Rather, we as hobbyists saw a foreboding, dark environment which had low pH, decomposing leaves, detritus,  and all sorts of seemingly contrarian, scary processes.

WE made it a "problem!"

As a hobby, I think we make lot of stuff "problems." 

When you think about it  many concepts in aquarium keeping started out as "problems", or were considered “impossible” until someone made them work.

Now, sure, I get the fact that Nature imposes "rules" on what we can do. There are consequences- often dire- to trying to break or circumvent natural processes. For example, trying to avoid the nitrogen cycle, or attempting to keep incompatible fishes together. Much of this stuff is common sense. However, it doesn't keep a lot of people from trying to "beat the system."

No look- I'm all for trying new ideas-pushing the limits of what's possible, and questioning the "status quo" in the hobby. However, trying to "game"eons of natural processes in order to create some sort of a "hack" doesn't only not work- it's stupid.

THAT is a problem that WE create.

You can, however, push the limits and break new ground by working within the boundaries of natural processes. That's advancement. That's progress. Innovation.

Many of us are working every day to progress in the hobby.

It took doing things that we hadn't previously done before- researching exactly what it was, what is required to create an aquarium ecology- and doing some things which were perceived by the majority of hobbyists as unconventional to get there.

But we did.

And now, we approach keeping botanical-method/blackwater aquariums not as a "problem" to overcome, but an approach which requires us to do specific things in order to do so successfully.

Among the most important things we can do is to push through mentally when we see how natural processes play out in our aquarium; how they impact its aesthetics...and how we view ourselves in the broader aquarium community. We do stuff differently around here. It is deemed "unconventional" by the vast majority of hobbyists. It's a different mindset than 90% of the aquarium world embraces. It opens you up to questions and criticisms in some quarters, particularly where other hobbyists have not grasped the idea and freed themselves from the pervasive hobby mindset which dictates what an aquarium is supposed to be like.

Yeah, we're different. Our process is different, our mindset and expectations are different, and the results that we see are different. 

The simple fact of the matter is, when we add 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 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 foundational to their existence, as it is in our aquarium approach.

And the fact that they recruit biofilms and fungal growths, and break down over time in our tanks is simply part of the natural process. We can consider this a "problem" which needs to be 'mitigated" somehow, or we can make the effort to understand how these processes and occurrences can benefit the little microcosms which we have created in our aquariums. 

It's about understanding, education, and acceptance.

As aquarium hobbyists, those of us who take this route are in a unique position to learn about and recreate many of the functions of Nature in our aquariums. We have the opportunity to go beyond long-held suppositions about what is "healthy" for an aquarium.

We have the opportunity to innovate.

When you're challenged after embracing on your first botanical-sale aquarium journey; when you're seeing stuff which "they" tell you is unwelcome, unattractive, and even "dangerous", ask yourselves how this conclusion was reached. Question why it is considered undesirable. Look at how your fishes are doing, and study the processes which are occurring in your tank, and how similar processes arise in the wild habitats which we seek to replicate.

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

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

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

Don't let the hobby's preconceived notions of what things are "supposed to be like" deter you.

Push though.

Stay focused. Stay observant. Stay bold. Stay diligent. Stay with it...

And Stay Wet.


Scott Fellman

Tannin Aquatics 



Behind the dynamics of the "Urban Igapo"

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

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

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

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

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

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

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

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

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


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


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

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

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

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

 Just add water, right?

Well, sort of.

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

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

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

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

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

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

Such a dismissive and judgmental attitude. 

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


The wet season in The Amazon runs from November to June. And it rains almost every day. And what's really interesting is that the surrounding Amazon rain forest is estimated by some scientists to create as much as 50% of its own precipitation! Think about THAT for a minute. It does this via the humidity present in the forest itself, from the water vapor present on plant leaves- which contributes to the formation of rain clouds.

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

That's crazy.

But it makes a lot of sense, right?

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

It's that simple.

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

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

Well, for one thing, rain performs the dual function of diluting organics, while transporting more nutrient and materials across the ecosystem. What happens in many of the regions of Amazonia, for example- is the evolution of our most compelling environmental niches. The water levels in the rivers rise significantly. often several meters, and the once dry forest floor fills with water from the torrential rain and overflowing rivers and streams.

The Igapos are formed. 

Flooded forest floors.

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

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

Leaves begin to accumulate.

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

Life flourishes.

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

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

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

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

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


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

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

You must be patient.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

And there are parallels in the management of aquariums.

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

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

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

Or not.

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

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

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

Nope. There is a lot of stuff to consider.

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

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

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

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

It happens in Nature, too!

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

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

And Stay Wet.


Scott Fellman

Tannin Aquatics  

October 25, 2021


Some of THOSE people!

This is the kind of post which usually gets me in trouble with some people. Yet, it's the kind of post which has to be made. A topic which must be covered once in a while, in all of its frightening ugliness. It won't win me any friends, but it's the price I pay for telling you what's on my mind sometimes.  I won't sugar coat it. 

There is no nice way to say it: Some people who haunt the forums and online groups of the world are just assholes, who seem to take delight in trying to thwart the ideas of others. 

No less than 5 of my friends have brought to my attention some rather unwarranted criticisms and attacks they have received on various Facebook user groups and forums when they brought up some "non-status quo" ideas on approaches to natural aquariums. 

I've seen this stuff in the hobby for years, but I'm seeing it more and more now, as some of my friends are starting to share their efforts and new ideas in these spaces. No sooner are these ideas brought up than the "winged monkeys" who inhabit these spaces descend and commence their pointless and misguided attacks.  

Yeah, there is a sad phenomenon which has emerged on hobby forums and groups in the past decade or so:

The continued emergence of...assholes.

Yup. You heard me. 

Assholes. Jerks. Know-it-alls.

The real problem that we have with some people in the aquarium hobby is that they are just plain arrogant...And negative. And, well- shitheads. These people abound on forums and Facebook groups. People who believe that they have all the answers about everything, and that everyone else is a fool or a "sheep" or whatever...They're the masters of false bravado."

And the way they seem to rear their ugly pathetic heads is always the same.

Here's how it goes: 

You share something on a forum or somewhere else online, and seemingly from no where, these people appear, and they're the first to tell you it's a stupid idea. They're the ones who jump all over your idea with negative feedback, ignorant "challenge" questions, and outdated or non sequitor assertions. They tell you why you can't do whatever it is you're doing. Now, lest you think I'm being a "snowflake" or overly sensitive, or whatever, I DO know what constructive criticism is-and this ain't it, folks!

These people seem to delight in telling you that what you're doing can't be done. They think they know everything, and they're damn afraid to have someone else come up with an idea, or worse- show some work- which challenges what they are comfortable with. So they lash out and attack.

These people are sad.

Some are flat-out assholes. They literally are the reason why the hobby sometimes faces high rates of attrition, or why progressive ideas which challenge the status quo are sometimes shot down in some quarters before they ever get off the ground. It's why many forums and groups simply are toxic sinkholes of ignorance and arrogance, rather than being great places to exchange experiences and ideas. The jerks are usually louder than the innovators in these places.

A lot of these awful people don't even have firsthand knowledge of what they are attacking, or come from a place of not even understanding the concept, intent, or methods behind the other person's idea.  Rather, they make assumptions based on how the idea presented squares with what they know. Anything which deviates from that, in their view, is "nonsense"- or a "waste of time" (actual words used in a recent attack on a friend of mine, btw). It's almost like a reflex for them.

Their ignorance- and hubris- are staggering!

They're scared. And they feel better attacking other people to feed their damaged egos. It's painfully obvious. I feel sorry for them...although many are such jerks that it's tough to be compassionate for them, lol.

And the sad thing is that many of these people attack others based on ideas or information they personally have limited experience with.

Often, these people simply regurgitate second-hand information, which they see and hear all over the internet, and act as if they have been appointed as the guardians of sacred aquarium hobby knowledge that is somehow being "blasphemed" when new ideas are presented which may challenge the prevailing narrative on a subject.


Just be wary of these really arrogant people, who simply parrot what they hear online or elsewhere, with an air of undisputed authority.  People who simply shit on anything which doesn't fit their narrative. Some people don't even read carefully what the other person is suggesting before they bring on the trash talk, making it painfully obvious to those who do that they don't have a clue what they are talking about!

It's a horrible thing.

We need to be much more open-minded as a hobby. To entertain all sorts of different ideas and orientations. We shouldn't simply accept all advice or ideas as "the gospel"- but we shouldn't outright trash anything without due consideration.

The bottom line is that you need to take all advice-from anyone-yeah, even ME- with a grain of salt. No one knows everything about aquarium keeping. No One... Regardless of their educational pedigree, or even regardless of how nice their tank looks. 

However, you don't have to completely trash the other person, either.

Something to contemplate.  

There are a lot of great people in the hobby who will support, consul, and join with you when you're trying new and exciting things. However, there are a smaller, but vocal minority of hobbyists who may be more destructive, and they require a bit of awareness on your part.

During the course of your aquarium keeping “career”, you will meet lots of different people who are also into fish. Many will offer advice- some welcome, and some unsolicited and not so welcome! I’ve noticed this since we've been in business, as well! People tend to come and “consult” with you, even if you’re not asking for it. It’s a good and bad aspect of aquarium keeping- fellow hobbyists are always willing to help. The problem is, some people are just not all that helpful, and can even prove detrimental to your enjoyment of the hobby! Some are just "keyboard warriors" looking for a fight.


The bottom line: You have to be downright careful about who you let into your home or aquarium “bubble” to “check out” your tanks and render advice. This is not rocket science, but in this social media-fueled, “everyone-knows-everything-because-of-Google” age, it’s pretty important to grasp.

I’ve actually classified the types of hobbyists who dispense advise and perhaps can make you feel bad, who you’ll run into now and again. They are, of course, generalizations, but they seem to be somewhat accurate, based on my experience.

  1. The “Diverter”-Diverters” are cool people who come into your home and check out your tank, and totally distract you from the direction you’re headed. These amazing people have a tendency to offer “corrections”- attempting to show you a “better way” to go- or something that you “need to do”- usually something that THEY strongly believe in…These people are well-intentioned, no doubt- but they really tend to steer you off course in a strange, vicarious fashion. “Diverters” tend to send you into direction that you never really intended- and not always for the better.  They may be amazing aquarists, but don’t let them and their clever ideas make you think for a moment that anything that you are doing is any less amazing. Be wary of these charmers!


2)  The “Deviant”- Fortunately, this is not a hobbyist that you will encounter often- but they are out there. “Deviants” seem to have all of the cool ideas and talk a big game- and they’re lucky enough to get away with some less-than-smart decisions in their fishkeeping, so they are always willing to send you down directions that are risky, and very contrarian. Although I’m a big fan of doing things your own way...I’m less interested in doing things that someone else was lucky to simply get away with.  If you find yourself continuously making bad moves every time a “Deviant” pays you a visit, best you steer clear of them!

3)  The “Taunt”- This type of hobbyist never seems to let you live down your errors or mistakes: “Remember when you tried to keep all of those Marble Hatchetfishes in your Discus tank? How well did that go?” Don’t let these people pull you back to the mistakes you might have made. What are they doing that for? To help you better yourself, or to express their own insecurities? Everyone screws up in fishkeeping. If you’ve messed up, it simply means that you’ve learned how not to do something. Keep moving forward- you’re good.



4) The “Hater”-  We all know a few, unfortunately. This is the type which prompted today's rant. These people lurk on forums and discussion boards, ready to strike. They want to be respected and admired by the fishkeeping community for having a great tank, etc., but don’t seem to want to  do any of the work to get there. Rather, they simply want to put down the work being done by everyone else. These are decidedly negative folks, but they can sort of motivate you in a weird way. Just don’t be like them. Share ideas, successes, failures, and render help to others based upon your experience. Use these negative thinkers to be the “anti-Hater” in the aquarium world. We need more "anti-Haters!"

5) The “Instant Gratification Specialist”- Yup, the internet aquarium keeping community abounds with these people. They’re the ones who put up those crazy, mega-priced build threads” that leave everyone in awe, and some people even feeling bad that they are mere mortals. These people often have the stated goal of building a tank that gets named “Tank of the Century” or whatever, as if that offers some legitimacy and “cred” to their existence in the hobby. 

I’m not hating on build threads that are started by genuinely excited hobbyists who want to learn and help others. This is a different breed of cat.  “IGS” types seem to have very little patience for anything but instant gratification. This will be evident in the speed in which the tank seems to come together, and the outlandish purchases that are posted regularly in their build threads. These people want to be liked. They are “fun” to be around in that respect, but are oddly sad in others. Many of them want be part of something bigger- they just don’t know what. The reality is that many of these people would be awesome friends, embraced by fellow hobbyists if they would just put their heads- and hearts- in the right place. 

6) The “Buzzkill”- Okay, everyone has seen this type of aquarist. These guys have a dark cloud following them, and seem to want to pull others into the cloud bank with them. A lot of them are extreme DIY-ers, who spend vast amounts of time and money trying to come up with fancy automated ways of doing the most basic of tasks, or trying to save a few bucks on stuff you'd normally pay for.  When these things fail to do the job, they blame luck. Maybe they’re unlucky, but they are almost always possessed by a “Why is this happening to ME?” attitude.  Many of them feel that the basics of aquarium husbandry just don’t apply to them, because they know a better way to do it.

“I don’t know why I’m having this algae issue. My automatic constant frozen food feeder and homemade fertilizer solution are working, but all of my parameters are off. The auto water conditioner/changer keeps sticking on me.  And the computer that controls my RO/DI membrane assessment keeps telling me the water quality is fine. I’m at wit’s end.”  It’s kind of hard to feel bad for these types, really. They seem to like to be in “Negative Land.” They must like the attention that the hobby community gives them. They may never change, because their arrogance won’t allow it. A pity, as they can offer a lot to the community with their skills.

Damn, the tone of this article is actually kind of dark and negative; I realize that.

You've just read my concise guide to the people you want to be aware of- or even avoid in the fishkeeping community- online or elsewhere.  It's sad I had to write this. Sure, these are generalizations, and there are others, no doubt. However, this will kind of give you a more detailed warning than perhaps you might find elsewhere…Hopefully it can help you avoid wasting valuable life energy with people who really have nothing positive to offer, and help you enjoy your hobby even more.

Now, these are just some guy's (mine) assessments of archetypes that can be pains in the ass in the hobby. The real problem that we have with some people is that they are just plain arrogant...And negative. And, well- shitheads. Those people abound on forums and Facebook groups. People who believe that they have all the answers about everything. 

However, don't shy away. Don't fail to share or experiment or progress in the hobby. Just learn to recognize when you're dealing with people who, because of their own issues, are not worth listening to.

As always, take any and all advise with a grain of salt. Have fun. Grow. Share. Avoid THOSE people whenever possible...


And Stay Wet, regardless.


Scott Fellman

Tannin Aquatics 


October 21, 2021


The "Unholy Trinity" and the Mental Shifts we must make...

The aquarium hobby tends to latch on to all kinds of ideas, practices, suppositions, and convenient facts. Much of what we believe in- or have been told to embrace, is good, solid stuff with practical applications. Some of it, however, is based on old information, uncorrelated facts, and simple fears.

We have been indoctrinated since our earliest days in the hobby to create optimum conditions for our fishes by scraping algae, removing biofilms, and siphoning out detritus.

Stuff that we, as lovers of botanical-style aquariums have learned not to be so stressed-out about, right?

Removing and eliminating those things from our tanks has become one of the biggest concerns for aquarists; algae control alone has become a lucrative category within the hobby, with tons of products, additives, tools, and gear dedicated to its eradication.

As aquarists, we're constantly made to think about the "perils" which the presence of naturally-occurring biological products can cause for our tanks. The reality is that most of our fears are, in my opinion, not only unwarranted, but are completely over-emphasized.

Often, our attempts at eradicating them leads to the formation of the very imbalances we are so consistently fearful of.

Let's start with one of the cornerstones of this "Unholy Trinity" of aquarium "scourges"- algae!

As we have literally beaten into your head relentlessly, in our truly "natural style" tanks, we don't really care if there is some algae in there. We've made that "mental shift" that says it's okay to have some decomposing botanicals, brown water, biofilms, and yeah...algae. Because natural aquatic habitats do, too. So it's not so bad, right?

Um, well, it isn't..at least in theory.

Let's think about algae in the aquarium to begin with...No, not the boring old "This is how algae problems happen in our aquariums..." lecture that you've read on every website known to man since the internet sprung to life. You can find that stuff everywhere. There are as many articles about how to control algae as there are aquarists.

Rather, let's think about how we, as a group, mentally are opposed to the stuff in our tanks. I mean, yeah, I know of no one that really enjoys a tank smothered in algae. It looks like crap, and is a "trophy" for incompetence in the eyes of most aquarists. In fact, I remember reading once that more people quite the aquarium hobby over algae problems than almost anything else.


Well, sure- algae problems caused by obvious lapses in care or attention to normal maintenance, like overfeeding, lack of water changes, gross overstocking, etc., are signs of...incompetence. The occasional algae outbreaks that many hobbyists suffer through have all sorts of other potential causes, and can often be traced to a combination of small things that went unchecked, and are typically controlled in a relatively short amount of time once the causative factors are identified.

Yet, as a group, us hobbyists freak out about algae in our tanks. I can show you a hundred pics of algae in the wild and say, "See it happens here too! Natural!" and the typical hobbyist will still be rendered speechless with horror should the stuff show up in their home aquarium.

We simply don't like the visuals of algae in our tanks. I get it. And excessive amounts of almost anything are indicative of an imbalance. However, since we are so into natural-style aquariums, isn't a little algae in our tanks...natural?

Is the presence of algae always a bad thing?


Algae is among the oldest, most adaptable life forms on the planet, and will exploit every available opportunity to flourish. Perhaps the biggest irony about algae is that, despite our disdain for the stuff, it's consuming some of the very nutrients that you don't want accumulating in the first place!  The real scourges! Its presence is quite beneficial in many cases, as it is an efficient processor of organics, produces oxygen, serve as food for many aquatic creatures and provides a "substrate" for small crustaceans and other life forms which our fishes consume as part of their diet.

When you think about it, the appearance of algae in the aquarium is actually an indicator that thing are functioning pretty well!

Sure, the "dark side" to algae is that it can smother your plants and cover everything if left unchecked. Now, that IS the sign of an unbalanced aquarium, when it's growing faster than your plants, or literally taking over every surface. And who willingly lets that happen?  No one. Some growth of algae on rocks and wood is not only not cause for alarm, it's really a natural and almost inevitable thing.

Wild aquatic habitats are filled with the stuff.

Yet, we have been trained over the century or so that we've been keeping aquariums to loathe the appearance of algae; to fear it and take drastic action when we see it. The bulk of the algae "problem", IMHO, is in our minds. It's that it's been perceived as an affront to our aesthetics in the mainstream hobby, because we've been told that an aquarium should appear near "sterile", or at least, devoid of any growth that we think is "unattractive."

And I think that's kind of sad.

The reality is, algae growth is important.

Again- algae is seen everywhere on the planet, and it's all over rocks, wood, and other submerged objects in natural watercourses. It's part of the rich fabric of life. Accepting that some algae is not only acceptable, but actually aesthetically interesting will take a "mental shift"- along the lines of the one that we make when we embrace a botanical/blackwater aquariums and its accompanying tinted water, decomposing botanicals, and biofilms. 

It's actually not only "part of the aesthetic" of underwater habitats, it's part of the necessary ecological framework. And that makes it a beautiful thing, doesn't it?Removing every bit of algae from your tank is not only impossible- it's impractical. And unhealthy for you aquarium.

So, next time you notice a little algae growth here and there in your tank, don't run off in a panic and reach for the algicide. Look at it and ask yourself if it's really "taking over" the tank,smothering your plants- or just exploiting a niche that's available to it.

Ask yourself if it's becoming a burden or danger to the fishes, or simply a "distraction" that you've been accustomed to fearing and reviling throughout your aquarium "career."

Along with algae, perhaps the most misunderstood biological occurrence in our botanical-style aquariums is biofilm.


Fairly regularly, we get emails or DM's asking about the "stringy stuff covering my leaves"- so it's always a good idea to discuss it from time to time.

Even the word conjures up an image of something that you really don't want in your tank. Something dirty, yucky...potentially detrimental to your aquarium's health. 

And, let's be honest with ourselves here. The damn dictionary definition is not gonna win over many "haters":

bi·o·film -ˈbīōˌfilmnoun -a thin, slimy film of bacteria that adheres to a surface.
Some charming and commonly-encountered examples of biofilm include plaque that forms on teeth, and the slime that forms on surfaces in water.
Shit. Really?
Add this to the fact that it's not the best-looking stuff you could find in an aquarium and- well, yeah..Its reputation proceeds it, right?

Yeah, I guess that's the definition we have to run with.

Well, apart from the unpleasant-sounding description of the stuff, and it's "snot-like" appearance, the concept of biofilms and how they form is actually kind of interesting.

Not "charming." I didn't say that. But interesting, for sure.

Biofilms form when bacteria adhere to surfaces in some form of watery environment and begin to excrete a slimy, gluelike substance, consisting of sugars and other substances, that can stick to all kinds of materials, such as- well- in our case, botanicals.

They are an integral part of flooded forest habitats...and pretty much every aquatic habitat there is. They assist with nutrient processing, sediment stabilization- oh, and they provide food for many fishes, too.

Is there a "darkside" to biofilms? Of course there is.

Like anything else, too much of a "good thing" can cause problems in rare instances.

Frightening, "aquarium armageddon scenarios" could play out. For example, in an extremely overcrowded aquarium (or a very small one) with marginal husbandry and filtration, with a huge amount of biofilm (relative to tank volume) caused by an equally huge influx of freshly-added botanicals, there is always the possibility that bacteria within the biofilms can multiply extremely rapidly, reducing the level of oxygen in the rest of the aquarium, which could lead to a dramatic increase of CO2 being released out of the water.

This, in turn, could lead to CO2 levels rising quickly and sharply, potentially causing asphyxiation to the animals in the tank- including the lovable nitrifying bacteria that support it.

Now, that's a true "doomsday scenario"- brought about by a non-sustainably-managed/populated aquarium, improper preparation and rapid, excessive additions of botanicals, and complete lack of common sense on the part of the aquarist, in terms of husbandry.

So yeah.

There IS a darkside to biofilms. If you create circumstances to foster one.

The real positive takeaway here: Biofilms are really a sign that things are working right in your aquarium! A visual indicator that natural processes are at work.

Yet, understandably, it may not make some of you feel good. However, it being "natural" and all...perhaps you could take some comfort in hearing more about what to expect?

First off, take comfort in the fact that this is typically sort of a "passing phase", and can take anywhere from a few days to 2-3 weeks before it subsides on it's own to some level that you can live with.  It will never fully "go away." You don't WANT it too. Realize that biofilms are present in every aquairium, to some degree. Yeah, even your "Nature Aquariums", guys.

Welcome to Planet Earth.

We get it, though- some of you just don't want this stuff, despite its "charms."

You can't remove every speck of it. You wouldn't want to. Like algae, biofilms serve as a primary means of nutrient export in our aquariums, and to remove them from the ecosystem would simply be detrimental. 

Again, the reality here is that in an otherwise well-managed, sustainably-populated aquarium, at best the largest blooms of the stuff will be a temporary nuisance, subsiding to a tolerable level, or even being almost unseen, for as long as you have the aquarium in operation.

Remember, it's all part of the game with a botanical-influenced aquarium. A part of that "mental shift" towards accepting and appreciating a more truly natural-looking, natural-functioning aquarium. The "price of admission", if you will- along with the tinted water, decomposing leaves, etc.

Biofilm blooms and their ultimate stable long-term presence in your tank are simply part of the "dues you pay", which ultimately go hand-in-hand with the envious "ohhs and ahhs" of other hobbyists who admire your completed aquarium when they see it for the first time.

Now, there are a lot of hobbyists who have come to admire, and even love the whole idea of biofilm. Like, those of you who love the ornamental shrimp. You understand the value of having a periodic "crop" of this stuff available for your shrimp to "graze" upon.

You actually are wanting to foster it. 

Biofilms are absurdly common in Nature, and a part of pretty much any aquarium, yet a bit more significant (and noticeable) when you play with aquatic botanicals. They are not to be feared- although they should be respected, studied, understood- and ultimately, utilized as food by aquatic animals!

Moving on to the last member of our little triad...Equally maligned and misunderstood. 

As those of you who read my little rants and listen to my podcasts know, one thing I truly can't stand is over-generalizations about stuff in the hobby.

And one of the most maligned, over-generalized topics in the world of aquarium husbandry is...detritus. We've talked about this before, but it deserves repeating...

My never-ending war on behalf of detritus continues.

Yeah, you heard me...On BEHALF of detritus!


Look, I know that  detritus comprised of uneaten food and fish poop, accumulating in a closed system can be problematic-especially  if overall husbandry issues are not attended to. I know that it can decompose, overwhelm the biological filtration capacity of the tank if left unchecked. And that can lead to a smelly, dirty-looking system with diminished water quality. I know that. You know that. In fact, pretty much everyone in the hobby knows that.

Yet, we've really sort of heaped detritus into this "catch-all" descriptor which has an overall "bad" connotation to it. Like, anything which is allowed to break down in the tank and accumulate is bad. Anything that looks like "dirt" is...well, "dirty", dangerous, and should be treated accordingly.

Now, "dirty-looking" and "dangerous" are two very different things, right?


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

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

Everyone thinks that it is so bad.

I'm not buying it.

Why is this necessarily a "bad" thing?

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

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

This is really important. It's part of the biological "operating system" of our aquariums. It's largely inert.

It's not all bad, right?

I think we should embrace this. Especially in a botanical-style aquarium, which essentially "runs" on the decomposition of materials.

In the flooded forest floors we find in Nature, the leaf litter "community" of fishes, insects, fungi, and microorganisms is really important to the overall tropical environment, as it assimilates terrestrial material into the blackwater aquatic system, and acts to reduce the loss of nutrients to the forest which would inevitably occur if all the material which fell into the streams was washed downstream!

Stuff is being used by a myriad of life forms.

Is there a lesson from Nature here that we can incorporate into our aquarium work?

I think so!

Okay, detritus as we see it may not be the most attractive thing to look at in our tanks. I'll give you that. It literally looks like a pile of shit! However, what we're talking about allowing to accumulate isn't fish poop and uneaten food. It's broken-down (processed) botanical-materials. 

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

What does it mean?

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

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

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

I think so. 

Test your water. Observe the overall health of your fishes and the aquarium...How problematic IS the presence of some detritus in your tank?  It likely isn't, just like it isn't an issue in Nature.

Now, I'm just one guy, but I personally haven't ever had issues with the complete decomposition of botanicals and leaves being left to accumulate in my aquariums. In almost three decades of playing with this stuff, and being a hardcore, water-quality-testing reef keeper during much of that time, I can't ever, EVER recall I time where the decline of a system I maintained could be pinned specifically on the detritus from decomposing botanical materials as a causative factor in reducing water quality.

In fact, I have never had a situation where water quality has been an issue in a tank not performing well. And I suspect- neither have many of you.

Incorporating regular water exchanges into your botanical-style aquarium system is vital.  It gives you the ability to dilute any potential accumulating organics/pollutants before they become a significant negative impact on water quality.

They simply give you a bit of a "buffer", essentially.

I don't need to go into the well-trodden reasons about why water exchanges are a good thing in the aquarium. However, I do need to give us a collective whack upside the head and encourage each and every one of us to think about this stuff from the perspective of an overall closed ecosystem. Think about what the nitrogen cycle is and does, and think about the impact of inputs and exports into and out of our closed systems. 


Embracing the presence of stuff like algae, biofilms, and detritus in your tank is not a zero-sum game. It's not like, you either have a ton of it in your tank, or none. Like so many things in the hobby, our aquariums will reach an equilibrium if we let them. The ecology in your aquarium will "find its way", and arrive at an optimum balance between input and export.

If we let it.

Embracing these things is not an excuse for blowing off the basic tenants of aquarium keeping. You still need to take care of your aquairum, even though you might be an "algae hugger."

Now, I get it. Not all of these processes have appealing visuals. I believe that we as hobbyists need to separate aesthetics from the overall functional benefits of the various life forms and processes which appear in and guide our aquairums' ecological systems.

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

Stay the course. Don't be afraid. Open your mind.

Study what is happening. Draw parallels to the natural aquatic ecosystems of the world. Look at this "evolution" process with wonder, awe, and courage. And know that the pile of decomposing goo that you're looking at now is just a metaphorical "stepping stone" on the journey to an aquarium which embrace Nature in every conceivable way.

Maybe, as the years go by, we as a hobby will overcome generations of fear over stuff like detritus and fungi and biofilms- the very life-forms which power the aquatic ecosystems we strive to duplicate in our aquariums. Maybe, rather than attempting to "erase" these things, which go against our "Instagram-influenced aesthetics" of how we think that Nature SHOULD look, we might want to meet Nature where she is and work with her. 

And we just might see the real beauty- and benefits- of unedited Nature.

And of course, the literal "basis"- the "fuel- for all of this stuff is the botanical materials themselves, breaking down in our tanks, as they've done in Nature for eons. The ultimate in "ephemeral", and perhaps the ultimate execution of the natural, botanical-style aquarium. 

Ahh..this "stuff."

These small, seemingly "annoying" end products of biological processes like decomposition, and the life forms that accompany/produce them are actually the most beautiful, elegant, beneficial friends that we can have in the aquarium...

We just need to embrace them. Understand what role they play in Nature- and in our tanks.

It's a mental shift.

A perspective of open-minded curiosity...and a willingness to look at things a bit differently and go beyond the usual and generally accepted hobby ideas on "stuff." It's not always pretty. It's not always right.

I'll give you that much. However, it's always, always worth considering and exploring. Because just accepting "status quo", keeping a closed mind to alternative ideas, and not pushing the edges from time to time is not just a little bit boring- it's denying fellow hobbyists the opportunity to learn about- and potentially benefit from- stuff we might have long been afraid of.

Keep exploring. Always. Keep an open mind. Think through what we have taken to be "the gospel" in the aquarium hobby for so long and ask yourself if it could use an addendum or two! 

Stay curious. Stay bold. Stay diligent. Stay patient...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


October 20, 2021


"Susceptible to manipulation..."

It's long been known in the aquarium hobby that various natural materials can be used successfully to manipulate the environmental conditions in our tanks. Why do we want to manipulate the environmental conditions in our tanks? Of course, it's to create optimum conditions for our fishes. And the art of environmental manipulation starts with the most basic of parameters, pH.

Probably the single most important measurable environmental factor which we can manipulate using botanicals is pH. Now, the idea of lowering pH with botanical materials is not at all  a new concept. Hobbyists have incorporated peat moss to help lower pH...in water with very low general hardness, for generations.

A question we get a lot around here is about the "water-softening capability of botanicals", to which I respond almost reflexively, "There is none." Botanicals will not help you soften hard water.

I believe that anyone who tells you this categorically simply does not have the correct facts. Ask them to explain how this process occurs. I'd like to know, 'cause I've found no evidence of this! 

To help make sense of it all, we need to all re-familiarize ourselves with the concept of carbonate hardness.

Now, before we get too far, I'll dispense with the necessary disclosure that my knowledge of water chemistry is quite basic, and I'm not asserting that anything discussed here is the "last word" on the subject. It's an explanation of some facts and ideas based on my limited college chemistry and understanding of these things from being a "practicing aquarist." At a certain point in discussion about this stuff with really knowledgable people, my eyes start to glaze over...There are plenty of you out here who could "school me" on this stuff, and I encourage your input on these more esoteric, yet very important aspects of the hobby. We will all benefit.

Ahh, back to that bit on carbonate hardness...

This is one of those terms, along with "general hardness" (GH), that we see bandied about all over the internet and in books and hobby discussions...It's super-confusing to me, as there are multiple ways of determining the hardness of water (in general, but for us it's for aquarium purposes).

"Hardness", is essentially a measure of the total concentration of specific minerals dissolved in the water, including calcium and magnesium, as well as other minerals like potassium and sodium. It is said that the concentration of these minerals in a given quantity of water contribute to the "hardness."

Oh, and what exactly is "soft water", anyways? In simple terms, soft water is water which has a relatively low concentration of calcium carbonate and other ions.

There are a few ways of measuring this.

As a reef hobbyist, I was long ago indoctrinated to utilize KH (from the german word "karbonate") to measure the carbonate and bicarbonate ions in a given aquatics system, which function as "buffers", and keep the pH from dropping. And KH is a component of GH, to make matters more confusing (KH can never be higher than the "general hardness" of the water because of this fact). And a lot of test kits will measure both...as if a guy like myself needs more confusion in his life...


Hobbyists really seem to want an inexpensive, "natural", or simple way too soften their water. Using some botanical-based stuff just seems like it would be so right, doesn't?

Yeah, it seems that way.

And there actually IS a possibility here, impractical though it may be...Our old friend and nemesis, the "OG" botanical material used in aquariums- peat moss!

We receive a ton of questions about peat moss...mainly, what it can do to manipulate environmental conditions- pH and hardness- in aquariums.There is a lot discussed about peat's ability to "condition" aquarium water. And, although some of the facts might a bit convoluted, there is some validity to this, believe it or not!

Yes, interestingly, it is known that our old and controversial friend, peat moss, has actually demonstrated some capacity to conduct ion exchange ( a process in which which unwanted dissolved ions in water are exchanged for other ions with a similar charge.) Ions are atoms or molecules containing a total number of electrons that are not equal to the total number of protons. (I know, if you're like me, that made your head start spinning almost instantaneously.😳

Think of it this way: Peat softens water by exchanging humic acids for magnesium and calcium.

It's actually true.

Peat effectively binds calcium and magnesium ions, while simultaneously releasing tannic and other acids into the water. These acids "work" the bicarbonates in the water, reducing the carbonate hardness and pH to some extent.

And it will tint the water as well, as we all know!

Interesting, right?

However, you can't just drop some peat into your tank and expect "Instant Amazon." This process requires "active peat filtration" (the water passing over over the peat itself) to make this happen. Of course, you could place some in the tank and just wait for the process to occur "passively"- but it will take much, much longer.

Being the curious, and occasionally reckless fish geek that I am, I played around with this idea once, to try to see if this does, indeed work.

And, well, it does sort of work.

However, it took a LOT of this stuff to do the job with this "dump and wait" technique. 

How much?

Well, a shitload, if you must know. (and I"m being technically accurate, too.)

Yeah, it took a shitload of peat, and a fair amount of time to reduce my Los Angeles tap water, with hardness exceeding ~240ppm and ph of 8.4 down to "workable parameters" of 6.4ph and a hardness level of around 40ppm. How much are we talking? It took a full 2-cubic-foot bag of peat, added to a 30-gallon plastic trash can, filled with with my tap water, over 8 days in order to achieve these parameters.

So, yeah. The idea does work. Not exactly efficiently, but it does work.

Based on my experience, you CAN soften water with peat to some extent if you're  dedicated to it, have time, the means to do it, and a willingness and ability to test your water. I've long ago lost that thrill that some people get from these types of "money-saving DIY!" methods. To me, I simply decided to forgo other indulgences, save my money for a while, and invest in  the RO/DI unit, and call it a day.

Yeah, an RO/DI unit isn't quite as romantic as dumping some peat into a barrel of water, but it's a helluva a lot more efficient.

My SpectraPure 4 stage RO/DI unit cranks out 80+ gallons of zero TDS, zero carbonate hardness water in a day. Now, one could argue that the rejection rate of RO/DI makes it less efficient- but hell, I water my garden with the reject water! And yeah, a unit like mine retails for around $300 plus USD, a lot more than a 2-cubic foot bag of peat, but the long-term, consistent efficiency, ecological "friendliness", and reliability is pretty obvious to me. 

All in all, for maximum efficiency, consistency, and control, just invest in an RO/DI unit and you'll create soft water with little effort and no mess.

Yeah, it IS a bit pricy to purchase an RO/DI unit, but well worth it, IMHO if your goal is to create soft, malleable water to use in your aquariums.

So, this long dissertation on peat was a roundabout way of discussing how you could accomplish some water parameter manipulation with natural materials. It's entirely possible. It just requires some realistic expectations, research, effort, testing, and work.

There are some botanical products which you could incorporate fairly reliably to lower pH in water with minimal carbonate hardness, like...cones.

Cones, such as Alder and others, have been used successfully for quite a few years by shrimp and fish breeders to lower the pH in their aquaria, as well as to stimulate breeding. Some claim that they provide some antifungal properties. I've seen claims of higher hatch rates for certain fish eggs when utilizing cones as "water conditioners" in spawning aquariums. Is there any merit to these claims? Well, there seems to be at least some anecdotal evidence that the cones (well, really- the humic substances that cones release) may offer some benefits.

More about this later.

What, exactly, is a "cone?"

To many of us "city folks", cones are those odd-looking things that fall off big old Pine trees in yards and parks, are cool to throw into the fire while camping ('cause they "crackle!"), and to throw at each other when you're a kid! Well, to science, a cone (known to botanists as a strobilus) is the organ on a plant that contains the reproductive structures.

At this point, I'm so tempted to make some sort of juvenile-sounding joke about how weird it was that we used to throw pine cones at each other- but I'll spare you. Anyways, cones come in male and female varieties, are well-studied by scientists, and have definitive charachteristics that make identifying each species. sex, and viability possible, but I won't bore you with those details right now!

So, as far as cones are concerned, as aquarists, we like them because they are known to contain those tannins and humic acids. And, as you know by now, here at Tannin Aquatics, we have a more than causal interest in stuff that "tints" the aquarium water and contributes to a more dynamic physical and aesthetic aquarium environment- and cones can make some important contributions.


First off, the varieties that we aquarists will typically use are Alder, Birch, and Casauarina. These have been used for aquariums for some time, each has their own "tint capability" and therefore, utility for our purposes! 

Alder cones are probably the "alpha dogs" of the cone-using world, and you'll find aquarists worldwide playing with them in their aquariums.We've been offering them to our customers for years, and they seem to be very popular. Hailing from the genus Alnus, there quite a few species found worldwide.

The varieties most commonly used in aquaria come from Northern Europe and The Pacific Northwest in North America. Alder trees are also known to have bark rich in tannins, so it's no stretch to conclude that the woody little cones also contain some tannins as well!


Now, Alder cones are small- typically only a few centimeters in length, varying by age and species- but they are powerful little "tinters!' It only takes a small quantity of these guys, steeped in water, to produce some decent color.  Now, of course, color is simply an aesthetic "measure", and has absolutely no correlation with the pH of the water. Please don't forget that concept!

However, in terms of pH manipulation, there are some possibilities here.

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

This same enthusiast extrapolated that it would take about 330 cones to lower the ph of 100 liters of tap water from 8.12 to a respectable 6.74 in about 2 weeks, with nicely "tinted" water resembling, in the hobbyist's own charming words, "a cup of tea"- music to our ears, of course, yet not exactly a scientific recipe.

So, suffice it to say, these little cones do pack a considerable wallop! Of course, no hobbyist I know is going to toss 300 alder cones in a 25 gallon aquarium to try to drop the pH by 1.38, but this exercise demonstrates the "capabilities" of these innocuous-appearing little cones, and demonstrates the need to treat them with some respect and start very slowly when using them in our aquaria! Because, well- damn- we are dealing with natural materials and to try to ascribe them precisely-delineated capabilities is really speculative.

The other cone commonly used by fish geeks is the Birch cone (Betula sp.), which has similar, although not quite as pronounced an effect on pH as Alder, in our rudimentary recreation of that other guy's slightly more sophisticated tests! Birch cones are a bit larger and more elongated, which apparently doesn't have much correlation with their "capabilities" as a "pH reducer" in the aquarium, but it's an easy identifier. Interestingly, birch extracts (from the wood, mainly) are used in other industrial capacities, such as treating leather and in flavorings.


A given quantity of Birch cones do seem to render a slightly darker tint to the water than Alder, in our opinions, but as we all know from me shaming you, tint is NOT necessarily indicative of the pH of water. And remember, very hard water is unlikely to have the pH substantially influenced by a reasonable amount of any cones or botanicals. Softer water (like RO/DI), with little to no general hardness, is far more susceptible to pH manipulation via botanicals, in our experience.

In order to round out our collection of cones, over the years, we've sourced the rather attractive Indian Casuaurina Cone (Allocasuarina and Alnus sp.), which come from the beautiful evergreen trees found throughout Australia, Oceana, and as non-native introductions into the Indian sub-continent (which is odd, considering the "Indian" moniker in the common name, right?).

These cones are somewhat lesser known in the hobby in Europe and North America, but have apparently been used in Asia for a number of years in the same capacity as Alder has in Europe. These are handsome, "fat-looking" cones that actually look kind of different to us.

CONFESSION TIME: As much as I love the idea of using cones in aquariums, I must admit that, in my opinion, they hardly look "tropical", and are best relegated to the utilitarian role of "media", used to influence tint, cultivate biofilms and fungal growths, and to a lesser extent, to lower the pH of the aquarium water in filters or media bags away from the display.

I just think they look- well, how do I sound politically correct? Um, shitty- in aquariums. To me, nothing screams "NOT FUCKING TROPICAL" more than a bunch of Alder cones in the aquarium proper.

Okay, well, that's just me. Of course, we'll now see a 30% drop in cone sales as a result of this micro-confession-rant shaming people into thinking they're ugly or whatever...Damn it! 😆

A lot of hobbyists- especially shrimp  enthusiasts, don't seem to be bothered by the look of cones in their displays. It's about the utility. And, if you're going to keep cones in your display aquarium, the Casuarina are the best candidates for the job, IMHO. Their ability to reduce pH is not quite as pronounced as Alder, or even Birch; nonetheless, they can impact water chemistry and definitely can influence the tint of the water!  And more important, they have a very "faceted" surface which seems to cultivate biofilms and fungal growths quite effectively.

Shrimp seem to love that!

So, how many cones do you need to use in your tanks? I'd be doing you a complete disservice if I even attempted to tell you with any degree of authority. I mean, we've had a few "baseline" numbers that worked for us, but for the most part, we need to experiment. It's really a matter of what works for you, the individual aquarist. 

In general, cones seem to be ideal candidates to use in filters, media reactors, or just passively somewhere in your aquarium where water flows over them gently.  As mentioned previously, they certainly make a great foraging area for shrimp, and the many -"faceted" surfaces (known, interestingly enough as "scales" to botanists) do a respectable job of recruiting biofilms.

Since shrimp and some catfish (I'm thinking Otocinculus) seem to love foraging in them, one could conceivably even sneak in some pelleted foods into the scales, turning them into unorthodox, yet effective "feeding stations" for these animals, or other bottom-dwelling fishes which might be out-competed in busy community tanks. 

In general, the cones mentioned here are known to science to have rather significant amounts of tannins in their tissues. As with most plants, the tannins are theorized to be present in cones to protect the mother plant from predators. With the tannins, their usefulness as aquarium "water conditioning media" is easy to understand in that context, right?

However, the other properties attributed to them by aquarists and hobby industry people are a bit harder to substantiate, IMHO. Many hobbyists who use cones will speak of their alleged "anti-fungal" and "antibacterial" properties, with little more than anecdotal experience (or less!) to substantiate these claims.

Unlike Catappa leaves, which have been studied by scientists in Asia and elsewhere for fisheries use as antifungals/antimicrobials, and which DO have some phytochemical constituents that may be useful in treating and preventing infections, we're really operating on the basis of inference and even supposition that, because the cones seem to do what leaves do from a pH and aesthetic standpoint, they must also have these "therapeutic" capabilities, right?


We have to break really careful about that. 

Of course, those of us who trade in botanicals need to be responsible when assigning these "attributes" to the stuff we sell, and not everyone in the industry does. I see lots of vendors selling these items around the world, with descriptions that absolutely imply that the cones have all of these amazing capabilities and should be used to lower pH, treat fungus, hatch eggs, etc.

As you know, that kind of overly-generalized, sales-oriented hyperbolic stuff makes me want to vomit.

It was the same with catappa leaves.

The last thing I wanted to do when I started Tannin Aquatics was to get caught up in touting all sorts of unsubstantiated claims about these leaves and the substances they contain, so I did my best to ferret out just what the ”real deal" is here! It it was helpful for me to at least try to extract some practical information out of the many claims about these leaves.

For many years, Betta breeders and other enthusiasts in Southeast Asia added catappa leaves to the tanks and containers that held their fishes, and noticed a lot of positives…Those breeders who actually fought their fishes seemed to feel that, when their fish were kept in water into which catappa had been steeped, they recovered more quickly from their fight-related injuries.

It really wasn't until I found some scientific papers on catappa extracts which documented their anti fungal properties that I began to accept this stuff a bit more. It was a lot of really serious scholarly research based on actual fisheries work that helped me change my mind.  Some good, solid, replicable experiments. It's a far cry from the usual drivel that we see spouted by a lot of aquatics vendors. That kind of stuff doesn't do much to elevate things, right? Usually, it's just these grandiose pronouncements about the alleged "miracle" abilities of botanicals and that's it.

Back to the cones, specifically, for a minute...

As much as I would love to share their enthusiasm and faith that they can do these things, until scientific aquarium-use-specific research is done on them, I think it's best to consider them as a means to provide some color to the water, to add some pH-reducing capability under certain circumstances, and for their ability to cultivate biofilms.  

We should state that it is thought by some to have possible therapeutic benefits for aquatic animals, the extent of which is not fully understood.

And that's it.

Yeah, I'm a damn "buzzkill", I know.

Although I'm personally skeptical of some of the claims about cones, I would encourage responsible hobby-level experimentation with cones as a possible "homeopathic" remedy or "preventative" for fungus and other possible fish maladies for those who are interested (I'm not).  Look, as long as we are open-minded, record our results, and don't simply ascribe every good (and bad) thing that happens to our animals while using the cones to their "properties", it is certainly with looking into!

The number of shrimp breeders I've spoken with and read about over the years who do use cones (mainly Alder and Casuarina) in their breeding/rearing aquaria with good results makes experimenting with them  too tempting to simply dismiss!

And of course, we can go on and on about the humic substances and tannins which are released by botanical materials in general, directly into the aquatic environment. That's a legitimate, known "thing", documented by a lot of scientific study. 

In the end, the ability of botanical materials to manipulate the aquatic environment is wide open for research. It's more than just theoretical that they are capable of doing some things to the environmental parameters of the water they are placed in. And yet, more work is needed on a hobbyist level if we really want to understand how the physical aquarium environment can be influenced by them.

So, don't be afraid to roll up your sleeves and work with this stuff. There is SO much to learn that it's not even funny! We're really at the ground floor of our understanding of how to manage botanical-style aquariums, and every one of us has an important role to play, helping to dispel myths, develop and perfect techniques, and add to the body of knowledge of botanical-influenced systems.

Whatever your course is...stay on it. Stay bold. Stay creative. Stay curious. Stay undeterred.Stay active...

And Stay Wet!


Scott Fellman

Tannin Aquatics


October 18, 2021


Under the influence...


It's fun to speculate on how the materials we incorporate into our aquariums can change the environment within them.

I can't help but wonder what sorts of specific environmental variations we can create in our aquarium habitats; that is to say, "variations" of the chemical composition of the water in our aquarium habitats- by employing various different types and combinations of botanicals and aquatic soils. 

I mean, on the surface, this is not a revolutionary idea...We've been doing stuff like this in the hobby for a while- more crudely in the fish-breeding realm (adding peat to water, for example...), or with aragonite substrates in Africa Rift Lake cichlid tanks, or with mineral additions to shrimp habitats, etc.

In the planted aquarium world, it's long been known that soil types/additives, ie;  clay-based aquatic soils, for example, will obviously impact the water chemistry of the aquarium far differently than say, iron-based soils, and thusly, their effect on the plants, fishes, and, as a (perhaps unintended) side consequence, the overall aquatic environment will be influenced significantly as a result.

So, it pretty much goes without saying that the idea that utilizing different types of botanical materials in the aquarium can likely yield different effects on the water chemistry, and thus impact the lives of the fishes and plants that reside there- is not that big of a "stretch", right? I can't help but wonder what the possible impacts of different leaves, or possibly even seed pods from different geographic areas can have on the water and overall aquarium environment.

I mean, sure, pH and KH are affected in certain circumstances - but what about the compounds and substances we don't- or simply can't- test for in the aquarium? What impacts do they have? Subtle things, like combinations of various amino acids, antioxidant compounds, obscure trace elements- even hormones, for that matter?

Could utilizing different combinations of botanicals in aquariums potentially yield different environmental results? In the future, will this lead to the potential  development of step-by-step "recipes" for creating various types of physiological reactions in fishes?  You know- scenarios like, "Add this if you want fishes to color up. Add a combination of THIS and THIS if you want the fishes to commence spawning behavior", etc.

It sounds a bit exotic, a bit gimmicky, even, but is it really all that far-fetched an idea?

Absolutely not, IMHO.

I think the main thing which keeps the idea from really developing more in the hobby- knowing exactly how much of what to add to our tanks, specifically to achieve "x" effect- is that we as hobbyists simply don't have the means to test for many of the compounds which may affect the aquarium habitat. We aren't even 100% certain which compounds are present in many natural habitats, right? Assays would have to be completed on wild aquatic habitats to determine this.

In addition, we'd have to sift through a lot of field research on the physical characteristics and water chemistry of the habitat of various fishes to see which compounds influence which specific behaviors or impart specific health benefits, right?

Tons of variables.

At this point, it's really as much of an "art" as it is a "science", and more superficial observation- at least in our aquariums- is probably almost ("almost...") as useful as laboratory testing is in the wild. Even simply observing the effects upon our fishes caused by environmental changes, etc. in the aquarium by our experiments is useful to some extent.

At least at the present time, we're largely limited to making these sort of "superficial" observations about stuff like the color that a specific botanical can impart into the water, the reactions of our fishes to the tinting, etc.

It's a good start. 

As hobbyists, we tend to make assumptions, which can sometimes be problematic. I mean, we've pretty much beaten the living shit out of the idea that, just because the water in your aquarium is brown, it doesn't mean that you have soft, acidic "Amazonian" conditions. So, admittedly, we in the hobby have to "up our game" a bit rather than make such assumptions based on something like the color of the water!

Of course, not everything we can gain from this studying is superficial...some botanical materials actually do have some scientifically confirmed impacts on the aquarium environment. And yeah, they DO happen to color up the water, right?

In the case of catappa leaves, for example, we can at least infer that there are some substances (flavonoids, like kaempferol and quercetin, a number of tannins, like punicalin and punicalagin, as well as a suite of saponins and phytosterols) imparted into the water from the leaves- which do have scientifically documented affects on fish health and vitality. 

Of course, I Say "infer" because, even though these compounds have been determined to be present in catappa leaves, how can we be sure that they are leaching into the water in our aquariums, and at what concentration? It's a guessing game at best; what we can do is operate on the assumption (gulp) that some of this stuff is getting into our tank water.

An assumption that our aquariums are "under the influence" of botanicals! 

When we first started Tannin, I came up with the term "habitat enrichment" to describe the way various botanicals can impact the aquarium environment. I mused on the idea a lot. (I know that doesn't surprise many of you, lol...)

Now, I freely admit that this term may easily be interpreted as much more of a form of "marketing hyperbole" than it is a technical description of what occurs when we add botanicals to our tanks. However, I believe that the idea sort of resonates, when we think of the aquarium as an analog for the wild aquatic habitats, and how the surrounding environment- the terroir- impacts the aquatic environment, right?

Wine, for example, has "terroir"- a concept which acknowledges that the environmental conditions, especially soil and climate, in which grapes are grown  give a wine its unique flavor and aroma... and coffee also acquires traits that are similar. Tangible effects and characteristics, which impact the experience we get from them.

Tangible effects.

And we hear the interesting stories from fellow hobbyists about dramatic color changes, positive behavioral changes,  rehabilitated fishes, and those "spontaneous" spawning events, which seem to occur after a few weeks of utilizing various botanicals in aquariums which formerly did not employ them.

I think that there is "something" to this.

Sure, a good number of these interesting events and effects could likely be written off as mere "coincidences"- but when it happens over and over and over again in this context, I think it at least warrants some consideration! 

I mean, there is something to it all, huh?

We're slowly beginning to figure this stuff out. We as aquarists often walk the line between amateur scientists/sleuths and artists.

Yeah, we’re artists. But we're more than that, too:

Mad scientists.

Fish geeks.


Yeah, artists.

And this stuff is really as much of an “art” as it is a “science”, IMHO.

There is so much we don’t know yet. Or, more specifically, so much we don’t know in the context of keeping fishes. We need to tie a few loose ends together to get a really good read on this stuff…until we get to the "Dial-a-River” additive stage ("Just add a little of this and a bit of that, and...".) that I talked about earlier.

But we're getting there...At least in terms of understanding some of the tangible benefits of botanical use, besides just the aesthetics. It's a slow, often tedious process, requiring us to do more than simply make assumptions. It often involves a lot of amateur sleuthing through relevant scientific literature, hoping to extract some kernels of wisdom.

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

You're making mental shifts...replicating Nature in our aquariums by achieving a greater understanding of Nature...studying and attempting to replicate different components of the natural habitats of our fishes than we have previously- like substrate. 

Yeah, we've opened up a whole new can of worms with the idea of functional substrates for botanical-style aquariums, haven't we? At least, I hope that we have! The substrate is one of the more overlooked aspects of the aquarium, IMHO. The substrates in wild aquatic habitats have so much more to do with the environment than we think that they do.

One study concluded that the Rio Negro is a blackwater river in large part because the very low nutrient concentrations of the soils that drain into it have arisen as a result of "several cycles of weathering, erosion, and sedimentation." In other words, there's not a whole lot of minerals and nutrients left in the soils to dissolve into the water to any meaningful extent!


This fascination I have about the relationship between aquatic and terrestrial ecosystems led me down the path of creating and experimenting with a new (for aquariums, anyways) class of substrate materials which I call "sedimented substrates", composed of a number of materials, including clays and sediments, which were intended to influence the aquatic habitat in "fish-centric" botanical-style aquarium systems.

Let's touch on them for a little bit, because I do receive a lot of questions about them from our community. 

First off, let me make it clear these substrates were originally intended for a very specific purpose: To replicate the terrestrial soils which are seasonally inundated in the wild. As such, they were compositionally different than typical aquarium substrates. This also means that they "behave" differently when used in our aquariums in a number of ways.

Like, they will make your water cloudy at first.

Scared yet? I hope not. Because, as it turns out, they are useful and interesting for all types of aquariums, not only the ones which replicate flooded forest and grassland habitats.

Why are they comprised of sediments and clays? 

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

Now, think about it. These materials have profound influence on the aquatic habitats in which they are found. Many of our favorite habitats are forest floors and meadows, which undergo periodic flooding cycles in regions like the Amazon, which results in the creation of aquatic habitats for a remarkable diversity of fish species.

Depending on the type of water that flows from the surrounding rivers, the characteristics of the flooded areas may vary. An important impact is the geology of the substrates over which the rivers pass. This results in differences in the physical-chemical properties of the water. In the Amazon, as we've talked about for years here, areas flooded by rivers of black or clear waters, with acid pH and low sediment load in addition to being nutritionally poor, are called “igapó."

This transition from terrestrial to aquatic results in a very unique ecology, worthy of our study as aquarists. It's a fascinating dynamic, weaving together ecology, biology, botany, and geology.

The flooding ("inundation") often lasts for several weeks or even several months, and the plants and trees need special biochemical adaptations to be able to survive the lack of oxygen around their roots during this period. 

Another interesting ecological adaption: During the inundation period, many of the forest trees drop their fruits into the water, where they are eaten by fish. As an interesting side note, ecologists have noted that some of these trees and plants are strongly dependent on the fishes to disperse their seeds through the forest, requiring that the seeds pass through the gut of a fish before it will germinate.


Fishes which consume matter found in the substrate (detritivores) and other materials in the substrate (omnivores) also play a fundamental role in the transportation of organic carbon, which is a source of energy for downstream fish communities. Through their foraging activities, these fishes enhance the "downstream transport" and processing of organic material and ensure the proper functioning of the aquatic system and its biological community.

So, we have the terrestrial environment influencing the aquatic environment, and fishes that live in the aquatic environment influencing the terrestrial environment!

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

And that's where a lot of people will metaphorically "leave the room."

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

And it just so happens that these products actually grow aquatic plants...pretty well, too! 

Okay, enough of the mini "infomercial" on our substrates. The concept of influences of external factors on our aquariums is super cool.

Land and water, working together, provide an amazing resource for the adventurous and interested hobbyist to explore in greater detail. These regions are diverse harbors of life, ranging from fungal and biofilm mats, to algae, to epiphytic plants. Decomposing leaves, seed pods, and tree branches compose the substrate for a complex web of life which helps the fishes we're so fascinated by flourish. And, if you look at them objectively and carefully, they are beautiful.

I think the botanical-style aquarium community can create a model for hobby-level contribution to the body of knowledge about these highly fascinating, remarkably diverse, surprisingly pervasive, and incredibly compelling natural aquatic habitats.  

As an aquarist, a little bit of faith in the natural process, and a willingness to let go of your preconceptions of exactly what an aquarium should look like- is absolutely necessary.

Even mandatory.

Once you free your mind of  these "prejudices", you will really begin to accept and appreciate the natural beauty of what these systems are all about. To understand the influence of all sorts of ecological factors upon the aquatic environment. To be willing to embrace these influences to create compelling, functional representations of some of the more unusual aquatic habitats of the world.

Hobbyists who incorporate botanicals and such into their aquarium nowadays are looking at things more "holistically', embracing the natural processes, such as the breakdown of materials, accumulation of biofilms, and even the occasional spot of algae, as part of the environment to be studied and enjoyed, rather than to be loathed, feared and removed.

We're learning more about the interactions between our fishes and these unique environments, and the opportunities to gain and share this new knowledge are endless! I think just having a bit more than a superficial understanding of the way botanicals and other materials influence and interact with the aquatic environment, and how we can embrace and replicate these systems in our own aquariums is really important to the hobby.

The real message here is to not be afraid of learning about seemingly complex chemical and biological nuances of aquatic ecosystems, and to apply some of this knowledge to our aquatic practice.

I also have this irresistible curiosity about the potential of botanical-influenced aquariums to foster a unique and complex ecology in our aquariums. With the diverse assemblage of microorganisms and a continuous food source of decomposing botanicals "in house", I can't help but think that ideas like "living substrates" create a surprisingly diverse and utilitarian biological support system for our aquariums.

I think that the idea of an "enriched substrate" will become an integral part of the overall ecosystems that we create. Considering the substrate as both an aesthetic AND functional component- even in "non-planted" aquariums, opens up a whole new area of aquarium "exploration."

Stay thoughtful. Stay resourceful. Stay creative. Stay studious...

And Stay Wet.


Scott Fellman

Tannin Aquatics 



October 15, 2021



Some 6 years into our adventure at Tannin Aquatics, the idea of tossing all sorts of botanical materials into our aquariums for the purposes of creating a diverse, functional ecological system is becoming more widely accepted in the hobby.

However, the real breakthrough with botanicals comes when you let them fully decompose in your aquarium.

Yeah, I'm talking about stuff breaking down in your tank. The idea of those nice crispy leaves and pristine seed pods softening, shedding their tissues, and ultimately turning into little bits and pieces of materials.

It requires a little understanding of the process- as well as an appreciation for what is actually occurring in order for most hobbyists to accept this. By making those mental shifts to accept these process and foster them- as well as their rather unique "aesthetics"- we are helping to unlock potential benefits for our aquariums as never before.

And it starts with stuff breaking down. The process of decomposition.

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 a botanical 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.

And it all is broken down into three distinct phases identified by ecologists.

It goes something like this:

A leaf falls into the water.

After it's submerged, some of the "solutes" (substances which dissolve in liquids- in this instance, sugars, carbohydrates, tannins, etc.) in the leaf tissues rather quickly. Interestingly, this "leaching stage" is known by science to be more of an artifact of lab work (or, in our case, aquarium work!) which utilizes dried leaves, as opposed to fresh ones.

Fresh leaves tend to leach these materials over time during the breakdown/decomposition process. It makes sense, because freshly fallen or disturbed leaves will have almost their full compliment of chlorophyll, sugars, and other compounds present in the tissues. (Hmm, a case for experimenting with "fresh" leaves? Perhaps? We've toyed with the idea before. Maybe we'll re-visit it?)

Cool experiments aside, this is yet another reason why it's not a bad idea to prep your leaves, because it will help quickly leach out many of the remaining sugars and such which could degrade water quality a bit in closed systems.

The second stage of the process is called the "conditioning phase", in which microbial colonization on the leaf takes place. They begin to consume some of the tissues of the leaf- at least, softening it up a bit and making it more palatable for the aforementioned detritivores. This is, IMHO, the most important part of the process. It's the "main event"- the part which we as hobbyists embrace, because it leads to the development of a large population of organisms which, in addition to processing and exporting nutrients, also serve as supplemental food for our fishes!

The last phase, "fragmentation", is exactly what it sounds like- the physical breakdown of the leaf by various organisms, ranging from small crustaceans and shrimp to fungi- and even fishes, collectively known as "shredders." It has been suggested by some ecologists that microbes might be more important than "shredders" in tropical streams.

Fauna composition differs between habitats, yet most studies I've found will tell you that Chironomidae ( insect larvae-think Bloodworms!) are the most abundant in many streams, pools, flooded forests, and "riffles" in the initial period of leaf breakdown! 

The botanical material is broken down into various products utilized by a variety of life forms. The particles are then distributed downstream by the current and are available for consumption by a variety of organisms which comprise aquatic food webs.

Six primary breakdown products are considered in the decomposition process: bacterial, fungal and shredder biomass; dissolved organic matter; fine-particulate organic matter; and inorganic mineralization products such as CO2, NH4+ and PO43-

An interesting fact: In tropical streams, a high decomposition rate has been related to high fungal activity...these organisms accomplish a LOT!


Interestingly, scientists have noted that the leaves of many tropical plant species tend to have higher concentrations of secondary compounds and more recalcitrant compounds than do leaves of temperate species. Also, some researchers hypothesized that high concentrations of secondary compounds ( like tannins) in many tropical species inhibit leaf breakdown rates in tropical streams...that may be why you see leaf litter beds that last for many years and become known features in streams and river tributaries! 

There's a whole lot of stuff going on in the litter beds of the world, huh?

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

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

Why fight it?

Alteration of the botanicals is done chemically via this microbial action; ultimately, the components of the botanicals/leaves (lignin, cellulose, etc.) are broken down near completely. In aquatic environments, photosynthetic production of oxygen ceases in plants, and organic matter and nutrients are released back into the aquatic environment.

All of these organisms work together- in essence, supporting each other via the processes which they engage in.

And, decomposition 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 the aquarium hobby, we are now accepting the use of botanical materials for a combination of reasons- what we call "functional aesthetics"- the capability of a material to influence the look and the function of the aquarium environment simultaneously.

A real "mental shift..."

Some hobbyists have commented that, as their leaves and botanicals break down  the scape as initially presented changes significantly-evolves- over time. Whether they know it or not, they are grasping Takashi Amano's interpretation of "Wabi-Sabi"...sort of. One must appreciate natural beauty at various phases of the aquarium's existence in order to really grasp the concept and appreciate it: To find little vignettes- little moments- of fleeting beauty that need not be permanent to enjoy.

We just plug along, feeding our fishes, doing water exchanges, and growing plants. We tend to our aquascapes, and watch things grow. And, over time, even the most diligently-maintained aquariums tend to look significantly different than when they did when they were first assembled.


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

And, if you look at them objectively and carefully, these assemblages are beautiful, both in aquariums and in the wild habitats which we strive to replicate. The idea of embracing Nature is not something entirely new or previously unconsidered in the hobby. However, the idea of accepting the look, function, and benefits of natural processes (such as formation of fungal growths and the decomposition of botanical materials) IS.

Of course, when we look at natural ecosystems where leaves and other botanical materials collect, the parallels in look and function between Nature and aquarium become far more obvious!

Understanding the transient nature of botanical materials is absolutely essential for the botanical-style aquarium enthusiast. There are many who prefer a crisp, clean collection of botanicals and leaves in their tanks, and go to great effort to keep them that way...They will remove any leaf that starts to break down or recruit biofilms, and replace them with new ones. If you're up to the task- I say go for it!

For most of us- those of us who've made that mental shift- we let Nature dictate the evolution of our tanks. We understand that the processes of biofilm recruitment, fungal growth, and decomposition work on a timeline, and in a manner that is not entirely under our control.

We realize that botanical materials- with all of their impermanence and imperfection- are "fuel" for ecological processes, which help dictate the diversity and health of our aquariums. 

This is another one of those foundational aspects of the natural style of aquarium that we espouse. The understanding that processes like decomposition and physical transformation of the materials that we utilize our tanks are normal, expected, and beautiful things requires us to make mental shifts.

We need to get over the "block" which has espoused a sanitized version of Nature. I hit on this theme again and again and again, because I feel like globally, our community is like 75% "there"- almost entirely "bought in" to the idea of really naturally-appearing and functioning aquarium systems.

Understanding that stuff like the aforementioned decomposition of materials, and the appearance of biofilms- comprise both a natural and functional part of the microcosms we create in our tanks.

Employing natural materials which tend to recruit these life forms during their time in our tanks is actually one of the joys of our hobby pursuits, IMHO.

It's all about how the natural materials that we play with fuel the process of establishing, growing, and maintaining a closed ecosystem in our aquaria. Knowing that the turbid, biofilm-and-fungal-growth-filled aquarium that you've recently set up will evolve over time to a rich, diverse, biologically stable microcosm.

Observing and appreciating this stuff- all of it- rather than instinctively reacting to it with fear or revulsion, is the key to success with botanical-style aquariums. Ask yourself, the next time you're inclined to run for the siphon hose or scraper, why you must remove it? Is it because it's somehow "harmful" to your aquarium?

Or, perhaps- could it be that we are so indoctrinated in hobby practice to remove anything which somehow offends our aesthetic sensibilities of what we think- or have been told for generations- that a "healthy" aquarium should look like?

DIg. Dig deep...and ask yourself those questions.

Consider that removing some of these things- decomposing leaves, detritus, biofilm and frugal growths, not only potentially removes someone's food source from the system- it interrupts fundamental and beneficial ecological processes which, despite their aesthetics, provide extremely valuable services for all of the life forms in your aquarium.

Botanicals are fuel.

Fuel for life. Fuel for natural processes which can yield benefits for our aquariums which we have spent years and countless amounts of money attempting to circumvent in our quest to recreate what Nature offers up for free, for all of those who would but submit to Her processes.

Be strong. 

Stay bold. Stay curious. Stay grateful. Stay open-minded. Stay calm...

And Stay Wet.


Scott Fellman
Tannin Aquatics 


October 13, 2021


Lessons learned on the road to global domination...And more...

Okay, that title sounds a bit ambitious; arrogant, even. I mean, "global domination" - seriously?

Well, look, when I started Tannin, the idea of "global domination" of this unique market segment- sort of an inside joke at first- was actually pretty easy to accomplish- 'cause there wasn't such a market segment to dominate! .So, yeah, here we are!

I think a lot of hobbyists give thought to the idea of starting their own business... And that's exciting to me! And, because we receive so many questions on the business side of Tannin, the topic today is sort of a review of where I've been as a business person and hobbyist, and lessons learned while I was making the transition from one area to the hobby to another- another thing that many of you have asked me to talk about. As you suspected, you can't really talk about the business without talking about the hobby it serves, so we may bounce in and out of the two areas during the course of this piece. Yeah, this thing's gonna go all over the place!

About 6 years ago, I made a little “pivot” away from the business end of the reef hobby world, to focus on my other aquatic obsession, natural, botanical-style/blackwater aquariums. I was a co-owner of an industry leading coral propagation and importation business. It was a lot of work, but a hell of a lot of fun. And it was getting to be a pretty big operation, too. But something told me that it was time to move on.

A lot of my reef-keeping friends were in total disbelief when the news broke. I left the business at sort of the "top of my game", as it was really breaking out. From a business standpoint, I could understand why people might have been a bit surprised. Yet, oddly, as much as I enjoyed it, there was this other "itch" that I had to scratch...something completely different and very original- in the freshwater world.

Yeah, my friends freaked the fuck out. I can see why that raised a few eyebrows among industry observers.

However, from a hobby standpoint, the response seemed a bit weird.

I mean, just because I focused my business efforts on the botanical-style aquairum world didn't mean that  I abandoned reefkeeping. Nope. Just put my business focus on a different challlenge. When I announced that I sold my interest in the coral biz and started Tannin, some of my daily blog readers (yeah, I wrote a daily reef blog, too) were literally thinking that I Lost it."Fellman's lost it and gone off the deep end!" Which, of course, I found amusing, because I'd likely "gone off the deep end" long before that, lol!

On the surface, this transition was a bit crazy, right?

Going from "A- Lister" in one world to complete obscurity in another was something a lot of people who knew me just couldn't believe I'd be okay with. It was awful comfy being invited to speak at conferences and clubs all over the world. If there was a "glamorous" part of the hobby, the "reef hobby speaking circuit" was it. Lots of travel, invites, and virtual "rock star" status!

No one really knew me in the freshwater world, so to me, it was totally cool being this opinionated "nobody", writing insane rants about weird topics, talking about "crossover hobby skills", and selling dried "twigs and nuts" intended to be placed in your aquarium to make the water brown and decompose. Yeah, wasn't an easy sell at first.

That took a while to sort of seep into the freshwater world! 

And, damn- it did!

We've helped to create a global movement in the aquarium hobby. And that's not some brag...It's a fact. It was my stated goal in 2015 when we started to do just that. It wasn't just to sell twigs and stuff. It was about creating something bigger. To sell the idea of a different approach to ecologically diverse, truly natural aquariums.

We had to start 100% from scratch to do it, though.

Just look for the terms "botanicals" or "botanical-style aquarium" anywhere in the aquarium world prior to 2015...They're just not there. You won't find them. There was no real "market" for botanicals in the aquarium hobby. Now sure, people added leaves and twigs and stuff to aquariums for generations before we arrived- but there was no resource; no specific methodology ascribed to the practice. No place you could turn for this stuff. It wasn't looked at as a way to create function-forward aquariums.

We didn't just launch a brand that sold stuff, we pushed our philosophy and idea and had to educate and create a "methodological infrastructure" along the way. Crazy shit!  And it was hard! Yet, totally fun! Now, sure, it took a few years to get our ideas out in a more concise, systematic manner. We spent a lot of time just talking about our vision of the concept of botanical-style aquariums and how they represent a functional version of Nature. Reassuring people (and ourselves) that the approach wouldn't kill every fucking fish you put in your tank was a big thing. 

Another lesson:  Spread your ideas relentlessly and continuously. As you know, we utilized this blog and the podcast to help disseminate our message virtually every day, where I give the usual "Fellman-fluff" to a whole new audience! I've been told (and I am starting to agree) that "The Tint" is literally the living work- the "bible" of the botanical-style aquarium approach. Six years of near-daily writing will do that.

Other brands have since launched in this space, which I've always seen as a sort of "proof of concept" that this botanical-style aquarium thing is a viable idea! We get a TON of questions asking me if I feel somehow "threatened" when a new vendor happens on the scene. And the reality is that I never saw the appearance of a new brand in this "sector" as some looming "threat"- which is an important lesson for many erstwhile hobby business owners to learn.

Yeah, it simply never bothers me. I'm too busy doing my own thing to worry too much about someone else's. It's not an issue.


Because we were founded on the very idea of going into new and obscure hobby niches and areas of interest that we love- ones which few, if any people are working; and certainly not trying to build businesses around. This approach of "scratching your own itch" gives you a lot of freedom to be creative, and if it excites others, they come along for the ride. You build your tribe. Create a brand, and build a foundation. Simple-and difficult- as that!

What makes one source for botanicals better than the others? I mean, a leaf is a leaf, right? (Well, not necessarily- quality is apparent...but there's more to it, of course)

It's the information. The ideas. The philosophy. How the idea is presented. That's hard. 

Here is the "meat" of my answer for those who worry about it:

Yeah- with more interest, more vendors, and more hype about botanical-style aquariums in general, there is a lot more "noise." Meaning, of course, a lot more B.S. to filter through...a consistent lack of information (with a few exceptions), and not a huge body of recent firsthand experience with botanical-style tanks for newbies to draw upon.

Tannin just keeps evolving and pushing out new ideas to the hobby- something I just love doing. We keep moving daily. We have literally dozens of ideas going right now related to the botanical-style aquarium world, which are like nothing you've seen before in the hobby- we'll be launching into new and exciting tangential directions for years!

Things never get stale, and would-be imitators become pretty obvious to the market. When you're there first and really crushing it, people who come into the space later have little that's unique to offer- and everyone knows it. Most don't take any time to educate the consumer on the idea behind the products they sell- cause that's all they want to do- sell shit. Let Tannin do the heavy lifting, right? Just regurgitate what we've done, without bringing anything new to the table. 

A "followers" mentality. And that's really sad. It's unnecessary. 

That's why most of them, ahem- suck. They take the easy way out. Replication has always been easier to accomplish than innovation.Look, I'm not simply trashing brands which want to do the same thing that we do. I'm trashing brands in my sector-or any hobby sector-which bring nothing newts the table. That simply sucks. Now, being first on the scene isn't a guarantee that you'll be the dominant brand. Or, even that you're the best. And, as the incumbant,  you can't get complacent, especially with innovation. You have keep going or you'll die. 

Lesson: Expressing yourself and your ideas via your business, and working in areas that you love will always differentiate you from the rest of the market.Take the time to buildout the "infrastructure" of your idea. It is not an "immediate results" sort of thing. It takes time.  It's a continuous process. Innovation never stops. Most brands get comfortable simply existing. It's not enough. You need to keep building upon what made you start the thing in the first place. The passion and energy you bring to the table will continue to make you unstoppable! Do the hard work- the stuff that no one else wants to do.

Always move forward. Think differently, and try to act upon your ideas as fast and frequently as possible.

For some reason, I am always drawn back to the reef world. Tannin is just six years old, yet headed into some very interesting things in the freshwater (and brackish) world. Our version of aquariums and aquatic displays is not the sterile green and white world you've come accustomed to in FW. It's not the overly-artistic "conceptual art" approach.

Rather, it's about living, breathing, earthy habitats, with tinted water, decomposing botanicals...in many ways, "reef like." Oh, and don't rule out a "niche saltwater re-entry" by Tannin at some point...All sorts of ideas here. Okay, enough about me and my company and business lessons for a bit.

What about lessons we can learn from thinking differently about other parts of the hobby?Let’s focus on our aquarium hobby world...The freshwater one...for minute. Yeah, the freshwater world...from a slightly different perspective, as we say.

It’s a radically different world than the reef world which I operated in for decades prior. It’s been established for more than century, and there are specialties for just about everything, making it unbelievably segmented (good and bad if you’re a marketer, of course- depends on how you look at it)! And the freshwater world, sophisticated as it may be, has some strong “cultural beliefs” which keep it hanging on to some, well… close-minded thinking, in my opinion. Oh, and many of them look at us reefers as trend-mongering hipsters. Now, some of that might be true, but the fact is that the reef keeping world can teach the old-school freshwater world a thing or two…

The majority of hobbyists tend to force our fishes to meet the environmental conditions that are easiest and most convenient for us to supply. We typically do without even thinking much about it.

I’m often surprised during conversations with some freshwater hobbyists who are thoroughly convinced that it’s important and beneficial to the aquarium hobby to have adapted fishes to our captive conditions, even to breed under them, rather than attempting to accommodate their needs by recreating the habitats from which they come. In other words, fishes which for eons have evolved to inhabit soft, acid waters are being “acclimated” to, and even bred under hard, alkaline tap water conditions. I mean, it works... But I wonder if there are any long-term impacts of this practice.

The idea of "repatriating" fishes which come from soft, acidic blackwater habitats from our "tap water" conditions back into the environmental conditions in which they have evolved, and learning how to manage the overall captive environment is by no means new or revolutionary. It's just that the hobby has sort of taken a mindset of "it's easier/quicker for US" to adapt them to the conditions we can most easily offer them.

Just because they can "acclimate" to wildly different conditions than they have evolved to live under doesn't mean that they should. I mean, it's not about us. Right? The consistently successful serious breeders have understood this for a long time, and we all should, IMHO. As we’ve demonstrated, it's not at all impossible to provide such conditions as a matter of practice…

Need an example of this concept? Well, look at what happened with the reef community! Once hobbyists devoted their energies to providing fishes/corals/inverts the conditions that these organisms required to thrive- conditions the organisms evolved in over eons- rather than the conditions that were "easiest" for the hobbyists to provide, the hobby exploded, with successes beyond our wildest dreams available to everyone who learned the rules of the game.

Vincent Thomas Tank.jpg

"The rules of the game..."

And yes, technology and products eventually showed up on the market to enable this process of more easily providing what corals need. NOT to adapt them to more easily/conveniently-provided low light, low flow, etc. conditions. Rather, it was to make it easier for the largest number of hobbyists to provide the natural conditions which make it possible for these organisms require to thrive. As much as we would have liked to be able to keep thriving reefs full of corals in table-salted tap water, nature won't let us play that way!

We have to play Nature's game.

To all my fellow reefers out there: Pat yourselves on the back. It’s a lesson learned early in the “modern era” of reefkeeping, some 30-odd years back, which has enabled landlocked hobbyists in frigid climates to be able to successfully keep delicate reef-building stony corals in their living room. It’s what has enabled an entire industry of dedicated professional coral propagators to grow enough coral to someday meet the demands of the entire market, making it unnecessary to harvest from wild reefs. It’s what’s enabled even the neophyte reef hobbyist to be able to enjoy the wonders of the tropical ocean in his/her very first aquarium.

Accommodating the organisms we want to keep based on THEIR needs. NOT the other way around. A valuable lesson that the entire aquarium community could learn from. And it’s just “the way we do stuff” around here as reefers. The cost of admission. No other way is considered.

That’s the kind of stubbornness I can get behind!

And relentlessness...A continuous push to improve and innovate. It never stops.

Constant, relentless effort to innovate, craft, work with what you've got, to improve and drive your business forward- regardless of what the competition is trying to do. Don't listen to the accolades, and don't get taken down by the criticisms. March to your own drummer. Work with what you've got. Move forward- in a manner that works for YOU. If you've got something people want, the market will decide, and you'll win. If youdon't...well, you still have options, right?

So, that's today's slightly long-winded answer to an oft-asked aquatics business question. Gotta run now..I have some new products to attend to! 

Don't stress out over this stuff. Enjoy the process.

Stay stubborn. Stay curious. Stay dedicated. Stay proud!

And Stay Wet.

Scott Fellman

Tannin Aquatics

October 06, 2021





(noun) - A system of methods used in a particular area of study or activity.

In the aquarium hobby, we love the idea of subscribing to an approach to keeping our tank, don't we? There is something very satisfying and comforting to many hobbyists about having a sort of roadmap to follow in order to achieve a desired, perhaps predictable set of results. 

Over the years, there have been many methods and techniques to accomplish different things in the aquarium hobby. Some have been ridiculously successful and very easy to replicate. Some things that we have labeled as "methods" over the years were really just ways to sell product.

Is the botanical-style aquarium a "method?"

I believe that it is definitely an approach...and likely a method, sure. And it's quite different than most any other we play with in the hobby. It's different, because the aesthetics, although fantastic, are not the primary purpose of this approach. The "big idea" is to foster a diverse and highly functional ecology within the aquarium through the use of a diversity of natural materials.

Here is what we "preach":

An aquarium is a miniature closed ecosystem, subject to the influence of external inputs and outputs. We believe that an aquarium can utilize all sorts of natural materials to not only create a structural habitat, but to encourage and foster the growth of biofilms, fungal growths, and other beneficial microfauna. In fact, you could say that just about everything we do with botanical-style aquariums is optimized to foster biology. 

First of all, this is a "no dogma zone." Sure, we have some opinions and ideas of how we like to run our tanks. We believe in experimentation and trying different things. However, we don't assert that our approach is the single best way to do stuff...not is it the ONLY way to do stuff...It's just a "way"- an approach. We can learn from EVERY single approach and style of aquarium keeping. Every one has some validity and ideas that you can pull from. Mix and match as you want, evolve stuff as you wish, and have fun in the process.

Here are some fundamental components of our approach:

Start at the bottom- literally.

Utilize a substrate that not only fosters a diverse ecological assemblage of organisms, but one which does not have excessive amounts of buffering capability. So, in other words, materials like silica would be a good start. If you're into our sedimented substrates, they would be a useful material to use. Planted aquarium substrates are also potentially useful, as they tend to acidify the water, rather than raising the pH.

We are into adding materials like bits and pieces of botanicals and leaves, twigs, and other materials into the substrate layer. The reasons for this are multiple. First, we have found over the years that the decomposition of materials like leaves and bits of botanicals fuel biofilms and fungal growths. In a addition to providing a substrate for them to attach to, they "process" these materials directly (particularly the aquatic hyphomyctes-the fungi). 

Why do we want these life forms in our tanks? Because they not only process nutrients within the aquatic ecosystem, but they serve as supplemental foods for higher organisms, from minute crustaceans all the way up to our fishes. They help facilitate a "food web" within our aquariums. 

Having this "culture facility" within the substrate makes a lot of sense, as the organisms have a place to grow and multiply which offers huge surface area, little in the way of disturbance form fishes (assuming that you're not keeping fishes which dig extensively!), and a large amount of material upon which to draw upon for sustenance.

In our world, the substrate is not an afterthought. Rather, it's a place where all kinds of biological activity occurs. A place where supplemental food production for our fishes takes place, and a diverse ecology which supports the aquarium's ecosystem can arise. 

We are big fans of what we call sedimented substrates: Aggregates of clays, sands, snd sediments. A little unconventional in the hobby. Let's talk more about those sedimented substrates for a minute.

We describe our products as "sedimented substrates", because that's what they are- consisting largely of clays, sand, soil, and other materials (mineral sediments!) which mimic some of the properties of the soils of South America and other locales that we find so compelling.

Now, one of the first questions people ask about our soils is "What makes them different than the other materials on the market?" Well, I could go on and on, but quite simply, the answer is that these substrates were formulated to replicate the terrestrial soils of these habitats, which become inundated during seasonal rains and flooding.

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

They weren't designed from the get go to replicate say, river, stream, or lake substrates writ large.

And, they weren't intended to be a "go-to" substrate to replace the standard commercial aquarium substrates, because: a) they're hand-mixed, and therefore more expensive, b) they're not specifically "aesthetic enhancements", c) they are not formulated to be general aquatic plant substrates d) because of their composition, they'll add some turbidity and tint to the aquarium water, at least initially (not everyone could handle THAT!)

Rather, the intention was that our first releases "Varzea" and "Igapo" were formulated to be "transitional" substrate materials- starting out as terrestrial, able to grow some grasses and plants, and eventually becoming saturated and ultimately, submerged, transitioning to a fully "aquatic" substrate material.


Perfect for use in our "Urban Igapo" simulations, which is exactly what we developed them for...you know, the classic case of "scratching your own itch!"

Of course, this begs the question, "Can't they just be used like 'conventional' aquarium substrates from the start?"

And the answer is, "Yeah, they could. However, what will happen, because of their ingredients, is that they will create cloudy, turbid water in your aquarium for a while." There is a reason why materials like fine clays and mineral sediments haven't been particularly popular ingredients in aquarium substrates before!

Some of the materials will not saturate immediately causing this turbidity for several days or more. Ultimately, however, the materials will settle out and you'd be good to go. If you're okay with this initial turbidity, go for it from day one!

Oh, and you shouldn't rinse this substrate. Use it right out of the bag.

One of the pleasant surprises of the "NatureBase" line has been that they do grow aquatic plants- quite well, actually. Surprising to us, because some of the ingredients that we used in our formulation aren't specifically well-known for growing plants. However, the others are more nutritious, and the "pluses outweigh the minuses", apparently! 

Okay, enough of the "mini infomercial" on sedimented substrates!

And, yes, we add a lot of botanical material to the substrates in our tanks. It's another fundamental aspect of what we do. It's part of the way that botanicals actually "work" in aquatic environments.

The texture and chemical composition of the botanicals' exteriors is really well-suited for the recruitment and growth of biofilms and fungal populations- important for the biological diversity and "operating system" of the aquarium, as we've talked about numerous times here. This is such an easily overlooked benefit of using natural materials in the aquarium.

Damn, this is starting to sounds very familiar, huh?

And of course, as we know, terrestrial botanical materials, when submerged in water for extended periods of time, decompose. If there is one aspect of our botanical-style aquariums which fascinates me above almost anything else, it's the way they facilitate the natural processes of life- specifically, decomposition.

Decomposition is fundamental to the botanical style aquarium.

We use this term a lot around here...What, precisely does it mean?

de·com·po·si·tion- dēˌkämpəˈziSH(ə)n -the process by which organic substances are broken down into simpler organic matter.

A very apt descriptor, if you ask me! 

We add leaves and botanicals to our aquariums, and over time, they start to soften, break up, and ultimately, decompose. Decomposition of leaves and botanicals not only liberates the substances contained within them (lignin, organic acids, and tannins, just to name a few) into the water- it serves to nourish bacteria, fungi, and other microorganisms and crustaceans, facilitating basic "food web" within the botanical-style aquarium, just like it does in Nature- if we allow it to!


Utilizing botanical materials and leaves in your tank, and leaving them in until they fully decompose is as much about your aesthetic preferences as it is long-term health of the aquarium.

It's a decision that each of us makes based on our tastes, management "style", and how much of a "mental shift" we've made into accepting the transient nature of materials in a botanical-style aquarium and its function. There really is no "right" or "wrong" answer here. It's all about how much you enjoy what happens in Nature versus what you can control in your tank. Nature will utilize them completely, as she does in the wild.

I tend to favor Nature, of course. But that's just me.

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

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

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

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

Understand that the process of decomposition is a fundamental, necessary function that occurs in our aquariums on a constant basis, and that botanicals are the "fuel" which drives this process. Realize that in the botanical-style aquarium, we are, on many levels, attempting to replicate the function of natural habitats- and botanical materials are just part of the equation.

And of course, these botanical materials not only offer unique natural aesthetics- they offer enrichment of the aquatic habitat through their release of tannins, humic acids, vitamins, etc. as they decompose- just as they do in Nature.

Leaves and such are simply not permanent additions to our 'scapes, and if we wish to enjoy them in their more "intact" forms, we will need to replace them as they start to break down. This is not a bad thing. It just requires us to "do some stuff" if we are expecting a specific aesthetic. 

This is very much replicates the process which occur in Nature, doesn't it? Stuff like seed pods and leaves either remains "in situ" as part of the local habitat, or is pushed downstream by wind, current, etc. - and new materials continuously fall into the waters to replace the old ones.

Pretty much everything we do in a botanical-style blackwater aquarium has a "natural analog" to it! 

These materials are typically broken down by fungi and bacteria in aquatic environments. Inputs of terrestrial materials like leaf litter and seed pods into aquatic habitats can leach dissolved organic carbon (DOC), rich in lignin and cellulose. Factors like light intensity, mineral hardness, and the composition of the aforementioned bacterial /fungal community all affect the degree to which this material is broken down into its constituent parts in this environment.

Hmm...something we've kind of known for a while, right?

So, lignin is a major component of the "stuff" that's leached into our aquatic environments, along with that other big "player"- tannin.

Tannins, according to chemists, are a group of "astringent biomolecules" that bind to and precipitate proteins and other organic compounds. They're in almost every plant around, and are thought to play a role in protecting the plants from predation and potentially aid in their growth. As you might imagine, they are super-abundant in...leaves. In fact, it's thought that tannins comprise as much as 50% of the dry weight of leaves!


And of course, tannins in leaves, wood, soils, and plant materials tend to be highly water soluble, creating our beloved blackwater as they decompose. As the tannins leach into the water, they create that transparent, yet darkly-stained water we love so much!  

In simplified terms, blackwater tends to occur when the rate of "carbon fixation" (photosynthesis) and its partial decay to soluble organic acids exceeds its rate of complete decay to carbon dioxide (oxidation).

Chew on that for a bit...Try to really wrap your head around it...

And sometimes, the research you do on these topics can unlock some interesting tangential information which can be applied to our work in aquairums...

Interesting tidbit of information from science: For those of you weirdos who like using botanicals, leaves and such in your aquariums, but hate the brown water (yeah, there are a few of you)- you can add baking soda to the water that you soak your wood and such in to accelerate the leaching process, as more alkaline solutions tend to draw out tannic acid from wood than pH neutral or acidic water does. Or you can simply keep using your 8.4 pH tap water! 

MORE "ARMCHAIR SPECULATION": This might be a good answer to why some people can't get the super dark tint they want for the long term...If you have more alkaline water, those tannins are more quickly pulled out. So you might get an initial burst, but the color won't last all that long...

This is something that we need to do a lot more research on. In the end, I'm still a huge believer in the use of reverse osmosis/deionized (RO/DI) water exclusively for botanical-style aquariums. It gives us the best chance of not only manipulating water chemistry characteristics to those we prefer, it also gives us the ability to reap maximum benefits from natural botanical materials- both aesthetically and functionally.

We're also seeing a growing body of science-backed evidence that humic substances, a key component of "blackwater" have significant health benefits for fishes, and may be among the most important factors which contribute to their health in both the wild and in captivity.

This revelation backs up what many aquarists who dabbled with catappa leaves and bark and other stuff in botanical-influenced aquariums, particularly Betta breeders in Southeast Asia, have asserted for years. In particular, it's thought that these compounds, derived from botanicals, have anti-fungal and anti-parastic properties, and offer protection against oxidative DNA damage and from physiological stressors.

With these health benefits now more clearly understood, there are more reasons than ever to appreciate the role that an environment which accumulates these humic substances can play in overall fish health.

Although the health benefits to fishes are fascinating and actually somewhat of a "game changer", like many hobbyists, my interests lie with the creation of aquarium that present a more natural-looking, functional aesthetic. The physiological benefits are a sort of "collateral bonus!"

And it always seems go back to leaves, doesn't it?

Leaves, the "jumping off point" of our botanical obsession, form a very important part of the aquatic habitats which we obsess over.

It is known by science that the leaf litter and the community of aquatic animals that it hosts is, according to one study, "... of great importance in assimilating energy from forest primary production into the blackwater aquatic system." 

There is something that calls to me- beckons me- to explore, to take note of these habitats and their intricate details- and to replicate some of their features in an aquarium- sometimes literally, or sometimes, simply taking components that I find compelling and utilizing them in my tanks.

Habitats like flooded forests and streams also function as a means to preserve the nutrients that would be lost to the forests which would inevitably occur if all the material which fell into the streams was simply washed downstream. The fishes, crustaceans, and insects that live in the leaf litter and feed on the fungi, detritus, and decomposing leaves themselves are very important to the overall habitat.

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

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


Learning more about the dynamics of stream habitats and the ecology of the surrounding terrestrial environments is just one fascinating and compelling area of study that we as aquarists can really get into.

Yes, it requires some study. It requires trying some new and seemingly wacky ideas (encouraging the accumulation of detritus, decomposing leaves, and epiphytic biofilm growth, for one thing!), and embracing some different aesthetics in our aquariums.

Let's focus on this "functional" dynamic for a second.

When we look to Nature, it's increasingly obvious that we can replicate much of it in our aquariums.This quote from a paper by Mendonca, et al, tells me us many cool things about the habitats we love to replicate:

"In Central Amazonia, terra firme environments (uplands that are not seasonally flooded) are drained by streams that have acidic waters due to the presence of humic and fulvic acids. The waters are poor in nutrients and the forest canopy impairs light penetration to the stream surface, so aquatic plants are virtually nonexistent (Junk and Furch, 1985; Walker, 1995).

In these oligotrophic environments, food chains are dependent on allochthonous material from the forest, such as pollen, flowers, fruits, leaves, and arthropods (Goulding, 1980; Goulding et al., 1988; Walker, 1991). However, small fishes are frequently abundant, and 20 to 50 species may occur in a single stream (Lowe-McConnell, 1999; Sabino, 1999)."

Studies indicate that an increase in species "richness" is positively related to the habitat complexity and shelter availability as well as current velocity and stream size, and that substrate, depth and current speed are among the most important physical features in many bodies of water, which contribute to the formation of numerous "microhabitats", all with fascinating ecology, environmental parameters, and fish population diversity.

 Stuff we've barely tapped into in the aquarium world yet!

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

It's a lot to take in. A lot to consider. Yet, these natural components form the cornerstone of our methodology.

Stay thoughtful. Stay educated. Stay observant. Stay patient...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

The commendable power of restraint.

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

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


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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Interesting, right?

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

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

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

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



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

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

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

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

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

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

But that's just me.

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

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

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

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


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

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

It's about common sense.

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

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

But, you already KNOW that

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

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

I'll bet that you already have.

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

And Stay Wet.


Scott Fellman

Tannin Aquatics