May 23, 2022


The power of Aquatic "Cross Training"

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

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

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

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

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

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beginner's world", or an "old person's game",  filled with brown fishes, cluttered fish rooms with disparate equipment, outdated thinking, and lack of progression.

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

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

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

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

Fast forward few years...

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

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

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

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

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

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

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

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

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

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

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

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



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

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

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

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

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

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

Do better, guys.

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

This is just my opinion, of course...

Whew...rant over. For now. 

Back to the "cross training" part...

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

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

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

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

No elitism. No snobbishness. No exclusivity. 

Just fun. And learning...

Learn from each other...

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

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

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

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

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

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

In fact, I think we already do.  

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

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

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

And Stay Wet.


Scott Fellman

Tannin Aquatics 





May 20, 2022


The whole picture...

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

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


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

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

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

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


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

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

These factors will tell the true story.

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

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

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

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

It need not be, IMHO.


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

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

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

What’s a good water-exchanging regimen?

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

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

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

This is a super-important point to remember!

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

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


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

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

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

Yeah, stuff does get disturbed and redistributed.

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

The benthic microfauna which our fishes tend to feed on also are affected by this phenomenon. And as mentioned above, the fishes tend to "follow the food", making this a case of the fishes learning (?) to adapt to a changing environment.

And perhaps...maybe...the idea of fishes sort of having to constantly adjust to a changing physical (note I didn't say "chemical") environment could be some sort of "trigger", hidden deep in their genetic code, that perhaps stimulates overall health, immunity or spawning?

Something in their "programing" that says, "You're at home...the season has changed, because there's an influx of new water...leaves are rolling around..." Perhaps not as "specific", but something like that, which can trigger specific adaptive behaviors?

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

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


Hell, yes.

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

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

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

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

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

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

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

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

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

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

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

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

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

And Stay Wet.


Scott Fellman

Tannin Aquatics 



Your fishes call it "food..."

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

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

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

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

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

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

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

I don't believe that this is mere coincidence.

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

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

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

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


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

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


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

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

Something is there- literally!  

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

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

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

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

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

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

Just like in Nature. 


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


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


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

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

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

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

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

Why not, right? 😆

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

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

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

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

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

We learn to appreciate it by looking to Nature.

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

A priceless natural resource.

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

A true gift from Nature. 

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

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


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

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

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

Yeah, he got it. 

You can, too. 

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

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

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

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

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

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

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

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

And Stay Wet.


Scott Fellman

Tannin Aquatics 

May 14, 2022


The really long game...

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

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

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

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

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

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

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

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

Crisp. "Fresh." Clean-looking.

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

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

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

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

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

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

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

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

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

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

Consistency. Our old friend.

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

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

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

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

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

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

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

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

Ah..consistency over time again.

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

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

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

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

Yeah, over time.

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

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

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


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

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

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

Just like in natural aquatic ecosystems...

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

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


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

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

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

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

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

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

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

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

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

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

Super easy, right?

It is. If you let it be that way.

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

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

This is not entirely unknown to us as aquarium hobbyists.

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

Yes, it's an evolution.

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

Earth-shattering? Not likely.

Educational? For sure.

Thought provoking and fun? Absolutely.

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

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

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

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

Some tanks decline over time.


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

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

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

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

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

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

Yeah, it requires a certain attitude.

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

A willingness to accept.

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

It simply takes time.

And patience.

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

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

What would you end up with?

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

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

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

Nature doesn't "edit." She evolves.

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

For some it is.

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

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

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

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

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

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

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

You should, too.

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

And Stay Wet.


Scott Fellman

Tannin Aquatics 


May 10, 2022


The part where Scott is on someone else's podcast...

As those of you who read and listen to the podcast version of "The Tint" know, I can talk. A lot. And it's usually about weird stuff. So, when I'm asked to appear on someone else's podcast, I do my best reign it in a bit, lol.

Last week, I was guest on the popular "RumbleFish Podcast", and the host, Paula Underwater, and I had a great conversation on different aspects of the botanical method approach and its place in the aquarium hobby. Something which we don't always talk about enough here!

So, check out and support this very good podcast - they have a lot of cool guests! And of course, give a listen to the episode that I'm in!

Stay informed...Stay Wet!


Scott Fellman

Tannin Aquatics 

Perpetual darkness...

Okay, that was an admittedly "dark"-sounding title, but it's perfectly appropriate for today's topic...How to get- and keep- your water as tinted as possible. Or, at least, what materials would do the best job in terms of "color production."

We as a group are kind of obsessed with this.

And yeah, it's a good question!

Now, first off- let's all remember that the color of the water has absolutely NO relationship to its pH or carbonate hardness. It just doesn't. You can have water that looks super dark brown, yet has a pH of 8.5 or whatever. And conversely, it's just as possible to have crystal clear blue-white water that's soft, and has a pH of 4.5. We have to get beyond the social media-style "blackwater" definition, which seems to be, "If the water is tinted, it's a blackwater aquarium!"

Now, look, if you just want the nice color but could care less about the pH and hardness, that's fine. For the benefit of the hobby as a whole, please don't perpetuate the confusing narrative about blackwater aquariums by telling others that you have "blackwater." You have a "tinted" aquairum. 

And that's just fine.

So, yeah-I'm not going to launch into a long drawn out description today about how ecologists define "blackwater" and what specific chemical characteristics make it up- we've covered it enough over the can deep dive here or elsewhere to get that. 

Okay, micro-rant over. Let's get back to the topic.

Remember, this piece is not about how to make blackwater...It's a little more superficial than's about creating an aquarium with color and maintaining it. 

First off, one of the "keys" to getting your color that lovely brown is to select the right types and quantities of botanical materials to assist. Now, I'll be the very first to raise my hand and call BS on anyone who claims to have a perfect "recipe" for how many Catappa leaves per liter or whatever you must use to achieve a specific color. Sure, you could come up with some generic recommendations, but they're not always applicable to every tank or situation.

Yes...there are simply so many variables in the equation- many which we probably haven't even considered yet-that it would be simply guessing. Just like Nature, to some extent...

What I can do is recommend some materials which we have found over the years to generally impart the most reliable and significant color to water. In no particular order, I'll give you my thought on a few of my personal faves. There are a lot more, but these are some that consistently show up on my "fave" list. 


Yep, you heard me. One of the very best sources of tint-producing tannins in our aquariums is wood. I've told you many times, wood imparts tannins, lignin, and all sorts of other "stuff" from the exterior surfaces and all of those nooks and crannies that we love so much into the water. 

Ahh...the tannins.

Now, I don't know about you, but I'm always amused (it's not that hard, actually) by the frantic posts on aquarium forums from hobbyists that their water is turning brown after adding a piece of wood. I mean- what's the big deal?

Oh, yeah, not everyone likes it...I forgot that. 😂

The reality, though, as you probably have surmised, is that wood will continue to leach tannins to a certain extent pretty much for as long as it's submerged. As a "tinter", I see this as a great advantage in helping establish and maintain the blackwater look, and to impart humic substances that are known to have health benefits for fishes.

Some wood types, like Mangrove ( a wood we don't have at the moment), tend to release more tannins than others over long periods of time. Other types, like "Spider Wood", will release their tannins relatively quickly, in a big burst. Some, such as Manzanita wood, seem to be really "dirty", and release a lot of materials over long periods of time. All will recruit fungal growths and bacterial biofilms.

And  the biocover on the wood is a unique functional aesthetic, too, as we rant on and on about here!


I'm a huge fan of tree bark to impart not only color, but beneficial tannins into the water. Because of its composition and structure, bark tends to last a very long time when submerged, and tends to impart a lot of color to the water over the long term.

And to be quite honest, almost all of the bark products we've played with over the years seem to work equally as well. The real difference in bark is the "form factor" (appearance) and the color that they impart to the water over time. Some, such as Red Mangrove bark or Cutch bark, will impart a much deeper, reddish-brown tint to the water than say, an equal quantity of catappa bark. And our soon-to-be-released Ichnocarpus bark really packs in this reddish brown color! You're gonna love this stuff! 

Ounce for ounce, gram for gram, I've always felt that various types of bark always impart the most color to the water over almost any other materials.

"Skyfruit Pods" 

These are very interesting, woody pods, derived from the outer "valve" of the fruit of the Swietenia macrophylla tree, which hails from a wide range of tropical locales (although native to Brazil), and are just the sort of thing you'd find floating or submerged in a tropical jungle stream. Often called "Skyfruit" by locals in the regions in which they're found because they hang from the trees- a name we fell in love with!

These botanicals can leach a terrific amount of tannins, akin to a similar-sized piece of Mopani wood or other driftwood. They are known to be full of flavonoids, saponins, and other humic substances, which have known positive health effects on fishes. Like bark, it lasts a good long time and recruits some biofilms and fungal growths for good measure.

Live Oak Leaves/Magnolia Leaves 

Despite their humble North American origins, these leaf types impart more color, ounce per ounce, than just about any of our fave tropical leaves. And they both last very long time...Like, I've had specimens of live oak leaves stay intact for several months!

It's really important to think of leaves as not just a "coloring agent" for your water, but as a sort of biological support mechanism for your burgeoning ecosystem. They actively recruit fungi, bacterial biofilms, and other microorganisms which enrich the overall aquatic environment in your tank.




Alder cones  (Aalnus glutinosa and Alnus incana)  and Birch cones (Betula occidentalis), have  been widely utilized by aquarium hobbyists in Europe for some time. Betta and ornamental shrimp breeders are fond of the tannins released into the water by these cones, and their alleged anti fungal and antibacterial properties. There has also been much study by hobbyists about the pH reduction attributes of these cones, too.

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

Now, I'm the last guy to tell you that a bunch of cones is the perfect way to lower pH, but this and other hobby-level studies seem to have effectively have demonstrated their ability to drive pH down in "malleable" (soft) water...

 Coconut-based products (Coco Curls, "Fundo Tropical", "Substrato Fino")

There's something about coconuts...The materials which are derived from the husks of coconuts seem to produce a significant amount of tannins and impart color to the water. Of course, "Substrate Fino" and "Fundo Tropical" are smaller, or finer-textured materials which work primarily as "substrate enhancers", and not strictly as "color-producing agents", because there is an initial "burst", which subsides over time. 

Now, one of the novel applications for these finer botanical materials to take advantage of their color producing ability is to place them in a fine mesh filter bag and allow water to flow around or through them, like filter media. Essentially, a more sustainable alternative to the old peat moss trick...

Oak Twigs

For an interesting look and some nice color, I'm a big fan of oak twigs. Oak has a nice bark which imparts a deep brownish/yellow color to the water and it's quite distinctive. There is a reason why our  "Twenty Twigs" packs are pretty popular, and it's not just because you get a bunch of cool sticks!

When mixed with leaves and/or other botanical materials, not only do you get an incredible "framework" for a cool ecosystem, you get an incredible aesthetic as well!

Now, this is an absolutely cursory list.. I could have easily listed 10 or more items. No doubt, some of you hardcore enthusiasts are screaming at your screens now: "WTF Fellman, you didn't include_______!"

And of course, that's the beauty of natural materials...There are numerous options!

Another note on the colors to expect from various botanical materials. As you might suspect, many of the lighter colored ones will impart a correspondingly lighter tint to the water. And, some leaves, such as Guava or Loquat, also impart a  more yellowish or golden color to the water, as opposed to the brownish color which Jackfruit and Catappa are known for. 

A lot of you ask about things that impact how long the water retains it's tint.

This kind stuff is a big deal for us- I get it! Many hobbyists who have perhaps added some catappa leaves, "blackwater extracts", or rooibos tea to their water contact me asking  stuff like why the water doesn't stay tinted for more than a few days. Now, I'm flattered to be a sort of "clearing house" for this stuff, but I must confess, I don't have all the answers.

So, "Why doesn't my water stay tinted, Scott?"

Well, I admit I don't know. Well, not for certain, anyways!

I do, however, have some information, observations, and a bunch of ideas about this- any of which might be literally shot to pieces by someone with the proper scientific background. However, I can toss some of these seemingly uncoordinated facts out there to give our community some stuff to "chew on" as I offer my ideas up.

Now, perhaps it starts with the way we "administer" the color-producing tannins. 

Like, I personally think that utilizing leaves, bark, and seed pods is perhaps the best way to do this. I'm sure that you're hardly surprised, right? Well, it's NOT just because I sell these material for a living...It's because they are releasing tannins, humic substances, and other compounds into the water "full time" during their presence in the aquarium as they break down. A sort of "on-board" producer of these materials, with their own "half life" (for want of a better term!).

And, they also perform an ecological role, providing locations for numerous life forms (like fungal growths) surface area upon which to colonize. They become part of the ecosystem itself. A few squirts of "blackwater extracts" won't do that, right?

The continuous release of tint-producing compounds from botanical materials keeps things more-or-less constant. And, if you're part of the "school" which leaves your botanicals in your aquarium to completely break down, you're certainly getting maximum value out of them! And if you are continuously adding/replacing them with new ones as they completely or partially break down, you're actively replenishing and adding additional "tint-producing" capabilities to your system, right?

There is another way to "keep the tint" going in your tanks, and it's pretty easy. Now, those of you who know me and read my rambling or listen to "The Tint" podcast regularly know that I absolutely hate shortcuts and "hacks" in the aquarium hobby. I preach a long, patient game and letting stuff happen in its own time...

Nonetheless, there ARE some that you can employ that don't make you a complete loser, IMHO.😆

When you prepare your water for water changes, it's typically done a few days to a week in advance, so why not use this time to your advantage and "pre-tint" the water by steeping some leaves in it? Not only will it keep the "aesthetics" of your water ( can you believe we're even talking about "the aesthetics of water?") consistent (i.e.; tinted), it will already have humic substances and tannins dissolved into it, helping you keep a more stable system.

Obviously, you'd still check your pH and other parameters, but the addition of leaves to your replacement water is a great little "hack" that you should take advantage of. (Shit, I just recommended a "hack" to you...)

It's also a really good way to get the "look" and some of the benefits of blackwater for your system from the outset, especially for those of you heathens that like the color of blackwater and despise all of the decomposing leaves and seed pods and stuff!

So, if you're just setting up a brand new aquarium, and have some water set aside for the tank, why not use the time while it's aging to "pre-tint" it a bit, so you can have a nice dark look from day one? It's also great if you're setting up a tank for an aquascaping contest or  other same-day club event that would make it advantageous to have a tinted tank immediately.

I must confess that yet another one of the more common questions we receive here from hobbyists is, "How can I get the tint in my tank more quickly?"- and this is definitely one way!

How many botanicals to use to accomplish this?

Well, that's the million dollar question.

Who knows?

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

We did, too, in the early days of Tannin. And it was kind of stupid really. There just is no hard-and-fast answer to this. Every situation is different. You need to kind of go with your instinct. Go slowly. Evaluate the appearance of your water, the behaviors of the fishes...the pH, hardness, TDS, nitrate, phosphate, or other parameters that you like to test for.

It's really a matter of experimentation.

I'm a much bigger fan of "tinting" the water based on the materials in the aquarium. Letting Nature have at it. The botanicals will release their "contents" at a pace dictated by their environment. And, when they're "in situ", you have a sort of "on board" continuous release of tannins and humic substances based upon the decomposition rate of the materials you're using, the water chemistry, etc.

Replacement of botanicals, or addition of new ones, as we've pointed out many times, is largely a subjective thing, and the timing, frequency, and extent to which materials are removed or replaced is dependent upon multiple factors, ranging from base water chemistry to temperature, to the types of aquatic life you keep in the tank (ie; xylophores like certain Plecos, or strongly grazing fishes, like Headstanders, will degrade botanicals more quickly than in a tank full of characins and such).

(The part where Scott bashes the shit out of the idea of using "blackwater extracts" and Rooibos tea. This could get nasty!)

If you haven't heard of it before, there is this stuff called Rooibos tea, which, in addition to bing kind of tasty, has been a favored "tint hack" of many hobbyists for years. Without getting into all of the boring details, Rooibos tea is derived from the Aspalathus linearis plant, also known as "Red Bush" in South Africa and other parts of the world. 

(Rooibos, Aspalathus linearis.  Image by R.Dahlgr- used under CC-BY S.A. 2.5)

It's been used by fish people for a long time as a sort of instant "blackwater extract", and has a lot going for it for this purpose, I suppose. Rooibos tea does not contain caffeine, and and has low levels of tannin compared to black or green tea. And, like catappa leaves and other botnaicals, it contains polyphenols, like flavones, flavanols, aspalathin, etc. 

Hobbyists will simply steep it in their aquariums and get the color that they want, and impart some of these substances into their tank water. I mean, it's an easy process. Of course, like any other thing you add to your aquarium, including leaves and botanicals, it's never a bad idea to know the impact of what you're adding. 

Like using botanicals, utilizing Rooibos tea bags in your aquarium requires some thinking, that's all. 

The things that I personally dislike about using tea or so-called "blackwater extracts" are that you are simply going for an effect, without getting to embrace the functional aesthetics imparted by adding leaves, seed pods, etc. to your aquarium as part of its physical structure and ecology, and that there is no real way to determine how much you need to add to achieve______.

Obviously, the same could be said of botanicals, but we're not utilizing botanicals simply to create brown water or to target specific pH parameters, etc. We're trying to create an ecology that is similar to what you'd see in such habitats in Nature.

Yet, with tea or commercial blackwater extracts, you sort of miss out on replicating a little "slice of Nature" in your aquarium. The building of an ecosystem.  Which is why we call this the botanical method. It's not a "style" of aquascaping! And of course, it's fine if your goal is just to color the water, but it's more of an aesthetically-focused aquarium at that point.

I also understand that some people, like fish breeders who need bare bottom tanks or whatever- like to condition water without all of the leaves and twigs and nuts we love. They want the humic substances and tannins, but really don't need/want the actual leaves and other materials in their tanks.

And, when it comes to tea and these commercial extracts, I don't think the stuff lasts all that long. I personally believe that the tint-producing tannins in "tea" are potentially taken up quickly by substrate materials, filter media, etc. And unless you're keeping tea bags in your tank on a continuous basis, you'll always experience some "color loss" after some period of time.

Yes it works to impart some color and tannins. Creating infusions or extracts is useful, if you understand their purpose and limitations. They have a place in the hobby for sure.

It's why we got into the game with our botanical-based "Shade" products. We're currently sold out and are working with our supplier on a reformulated version. Seems as though we need to make a "darker" mix!

On the other hand, if you're trying to replicate the look and function (and maybe some of the parameters) of THIS:

You won't achieve it by using THIS:

It's simply another shortcut.

Not good or bad. Just a way to get the end "effect" faster, and without the other collateral benefits we discussed.

And look, I understand that we are all looking for the occasional shortcuts and easier ways to do stuff. And I realize that none of what we proffer here at Tannin is an absolute science. It's likely more of an "art" at this point, with a little science behind it.

Think about it: There is no current way available to the hobby to test for "x" types or amounts of tannins (of which there are hundreds of types) in aquariums.  I mean, there are tannin test kits, but they're used for wine making and such...Perhaps there is some tangential application for our purposes, but I'm not really sure what practical information. we could extract from the results.

And, I have not found a study thus far which analyzed wild habitats (say, Amazonia) for tannin concentrations and specific types, so we have no real model to go on.

The best we can do is create a reasonable facsimile of Nature.

And, in Naturę, a lot of the tint in blackwater environments comes from dissolved fulvic and humic acids from...soils. Yeah, geology is the key, IMHO, to truly "realistic" blackwater habitats. This is why I've been very picky on sourcing the materials and figuring out recipes for our NatureBase sediment substrates. They are intended to support these types of systems.

Understanding substrates and their role in both the physical environment and the ecology of our aquariums is still a wildly under-appreciated concept in the aquarium hobby, IMHO. We'll keep coming back to this in the future, I'm certain.

And keeping the water tinted is something that many botanical method aquarists are interested in. This wonderful "collateral benefit" of our approach is something that's easy to get addicted to!

Now, all of these ideas are okay to impart some color to your water. Some do more, as we've discussed ad nauseam. And none of them will work to full advantage if your aquarium is removing them as fast as you're imparting them into the water. So, go easy on chemical filtration media like carbon. I didn't say NOT to use them...Just don't use a ton of them! Use less than what the manufacturer recommends. 

What about plants?

Well, I have a theory about plants and tannins...

First off, as you know by now, you absolutely can keep plants in blackwater aquariums. We've talked about this a million times over the years. And yet,  interestingly, you can't always keep "blackwater conditions" (at least, color-wise) in planted aquariums! There has been much geeky discussion on this topic.

Tannin are interesting things. Think about this:

Tannins are known to bind up heavy metals and minerals. The roots of aquatic plants prefer to take up bound-up minerals and metals...So, another theory of mine is that heavily planted tanks do actually remove some of the visual "tint" (ie; the tannins) from the water via uptake from their roots. 

Make sense? Maybe?

Okay, I could go on and on all day throwing out all sorts of theories and unsubstantiated (via lab tests and rigorous studies, anyways) ideas on this topic...But I think I gave you enough here to get the party started. I encourage you to do some homework. We need to ask these questions to people who really understand the chemistry here. I think that there might be some good answers out there.

And, back to the "color thing" to close on here...

I admit, visual "tint" is probably THE single most superficial aspect of what we experience with botanical-method aquariums- but the most obvious, and likely the most impactful to the casual hobbyist or observer.

It's just as important to understand the collateral benefits of utilizing botanical materials- a subject we've discussed dozens of times here. However, in the end, it's the look of your aquarium that is what you have to experience each and every day, and if having an understanding of which materials can bring you the aesthetic experience you're after in a more effective way- well, then this is a worthwhile discussion, right?

I think that it is.

Stay curious. Stay resourceful. Stay enthusiastic. Stay observant. Stay appreciative. Stay tinted...

And Stay Wet.


Scott Fellman

Tannin Aquatics  

May 03, 2022


Welcoming the unexpected...and resisting the urge to overthink...

One of the great joys of the aquarium hobby is that, despite our careful planning, "stuff" can happen to our tanks that we didn't anticipate...And not all of it is bad!

We spend an awful lot of time worrying about every contingency, stressing over how our tanks will operate or why  "x" happened, despite our extensive planning to avoid such things. And often, whatever it was that happened wasn't all that "bad."- we as hobbyists just tend to classify anything which doesn't go exactly to plan as an "issue."

I was talking to one of my friends recently about what was going on in his cool fish room, and he was telling me that he was just looking to see what fishes were “breaking out”, which ones could be doing better, and which ones were in trouble. A cool, useful practice that many of us engage in with our tanks.

He reflected on the fact that, on any given day in a lot of fish rooms, you’ll find fishes or tanks that are kicking ass, some that could look better, and some that just declined for no apparent reason.


“No apparent reason…”

I find that expression intriguing.

Familiar words, actually. I hear them often when talking to fellow hobbyists who, when talking about the goings-on in their aquairums, will say things like, “…and they were looking great the other day, and today- they’re just failing to thrive for no apparent reason.” 

You see it on the forums- at least a dozen threads every day about “anomalous” fish losses. This is not a new thing. It’s not even an unusual thing. It happens. A lot. 

In a given community of organisms, all sorts of stuff happens from day to day.

Back when I co-owned a large coral propagation operation, with thousands of corals under our care, we needed to assess and get to the bottom of whatever went wrong- because if it spread, it could have jeopardized large amounts of our inventory. Not good when you make a living growing corals. Oh, sure, we had safeguards in place, but sometimes stuff slips through, and you need to attempt to find the root cause of the problem, lest it occur elsewhere in your facility.



Over the years, I’ve learned that there is ALWAYS a reason why fishes or corals struggle or die. We may not always find the ONE factor- the one thing that did it…But there is always a reason, or bunch of reasons- why the fishes or corals didn’t make it. It's not just "because..." The explanation may be beyond our ability to decipher, but it's out there. Stuff-good and bad- just doesn't happen for "no apparent reason."

On the other hand…sometimes, you just can't seem to pin it down, right? You go through the mental checklists of things that you do. Some change in the usual product additions, feedings, procedures, etc. You look at water parameters, search for trends. Look for one thing you did differently two days ago that could have been the trigger for the calamity…And still, the answer eludes you.

The unfortunate, unscientific, and altogether unsatisfying conclusion that we come up with after exhausting the obvious- and even the obscure- is often- the fish simply died for “no apparent reason.”


That sucks. It’s frustrating, because of course, there are reasons why the fishes died. Often, its more than one factor that contributed.

And you can’t find them. Can’t pin down the cause.

Without sounding like the proverbial broken record, this reinforces the usefulness of practices like regular water testing, because when tests are performed regularly and evaluated frequently, you’ll spot trends.

Trends are super important in aquarium management, aren’t they?

They help you see what direction your system is headed. They help you see if your parameters are stable, swinging all over, or just headed in one direction or another. Without getting too caught up in “big data”, you can get some good feeling for how your tank is doing by sifting through your test results from time to time. 

This seems obvious, but you'd be surprised how often many of us don't do this...

And there is no substitute at all for the simple, and often quite enjoyable- act of just looking at your aquarium. Every parameter is important, but if your tank looks like shit, does it really matter if phosphate is .04ppm or .08ppm? Your eyes are probably one of the best aquarium testing devices ever conceived…you just need to apply them regularly! In our busy lives, the surprisingly simple act of allocating the time to just look at our beautiful tanks sometimes eludes ironic is that?


So the altogether unsatisfying conclusion of this discussion? Sometimes you just can’t find the source of the decline in your aquarium, or why you lost that particular fish. Sometimes the data eludes us. 

There are a lot of “moving parts” in a typical aquarium, and the failure of any one of them may or may not trigger a problem…it can be frustrating ferreting out which of the 5 dozen possible things that could have gone wrong might have lead to the "problem" you experienced. And it's very easy to simply overthink; over-analyze everything. 

Just don't beat the shit out of yourself by overthinking stuff. 

I think there is something about tropical fish and aquariums in general that invites over-thinking" stuff.

Yeah, we've kinda made a damn art form of it.

Cases in point:

Algae blooms.

We analyze every possible cause, sometimes embracing on multiple courses of action, and then ultimately realize that it boils down to the fact that we had excessive nutrients in our source water, something that could have been addressed first, and with appropriate actions taken, would have solved the problem much faster!

Sometimes, we attack the problem, but spend valuable time on the wrong part of it.

Disease outbreaks? 

I get a lot of emails from aquarists trying to figure out how the new fish caused their disease outbreak ("It appeared healthy, and my LFS quarantines all new fishes"), when the reality is that it DID, and that it would be far better focusing on the solution- that being, removing the fishes to a treatment aquarium, etc.- and for the future, instituting a rigid quarantine protocol for future additions. 

We already know the answers to some things...I think that we just sometimes don't like to hear them. We know that we need to quarantine new fishes for the maximum protection. We just don't always want to execute on that...

We know how to solve most of the problems that we encounter in the hobby. As a group, we're actually pretty damn good at aquarium keeping. A century or so of "modern" aquarium keeping experience has definitely paid off.

Yet, we sometimes make things more complicated than we need to, adding layers of complexity to problems that, although important or critical, can be more than adequately addressed by simply DOING something we already know how to do.

Water quality is important in closed systems. Water exchanges are simple, economical, and probably one of the very best thing we can do as aquarists to keep captive aquatic animals healthy for long periods of time. We know this...

Many aquarists just absolutely despise them, and will go to great (and often expensive) lengths to avoid doing them, or to make them less onerous. Yet, an entire cottage industry of gadgets, procedures, etc. exists around the premise of "Eliminates water changes!" or "Reduces water changes!"

I mean, how many hobbyists do you know who developed "automatic water change" systems for their aquariums, with a lot of experimentation, complexity, labor, expense- and sometimes, consequences? In fact, I know at least two hobbyists who had to submit homeowner's insurance claims for damage caused by an "automatic water change system" that they designed and built!

Why not just perform a water exchange the old fashioned way? A siphon hose and a bucket can do wonders. It's not even that big a deal, gets you intimately involved with your tank, and doesn't take all that much time.

I think that even scientists tend to "reinvent the wheel" and make things related to aquariums more complicated than they have to sometimes!

I saw a segment on one of those cable news magazine shows not too long ago about how scientists were working on this "novel way to help restore coral reefs that were threatened by global warming, etc.", and how they went to all of this effort to collect coral larvae, let them settle in the lab, then attach the young coral to rock on a reef. Collecting coral larvae is difficult, time consuming, and resource-draining.

I couldn't help but reflect upon the fact that we, as hobbyists, have been fragmenting and propagating corals for some 3 decades now, both at a personal and commercial level. Literally cutting them into fragments and gluing them to ceramic plugs or rocks...and we grow them by the tens of thousands all over the world. Coral farming is not some esoteric theoretical thing. It's being done every day on a practical level.

I remember watching this and was like, "Guys, if you need coral to restore a coral reef, just visit a local reef club meeting! They'll hook you up. Why are you making it so complicated?"


Now, granted, there's a bit more to it than that, and I cannot downplay the achievements of the scientists involved...collecting and studying larvae and all...but man, if you want to restore a reef...quickly, why not just make some frags?

And the best part of the segment was that there was an admission by a scientist working on the project who said something to the effect that, "As scientists, we're great at studying corals, but not great at growing them." So what did they do? They turned to aquarists! ( I knew they'd get there eventually!)

It's also long been a reef hobby joke that scientific institutions generally have reef aquariums in their facilities that are, ahem, "less impressive" than an average home aquarium!

Granted, there are many awesome reef tanks at public aquariums, but generally, to a hobbyist, a surprisingly large number of them are underwhelming, despite the obvious availability of manpower, equipment, and resources available for the institutions to create and  maintain them. My advice? Just call a reef club, tell 'em what you need, and be done with it already! They'll hook you up! You don't think hobbyists would literally crawl all over each other to be involved in a project like that?

I know, this is a harsh, generalized, and sort of unfair assessment...But yeah, it serves as an example of how aquarists often tend to overthink aquarium-related stuff, even at "higher levels."

As aquarium hobbyists, think of the time, money, aggravation, and energy that we can save if we just focus on the actual problem, and don't over think ways to solve it.

In fact, sometimes, it involves NOT micro-managing every aspect; controlling each and every aspect of what goes on in our tanks. Sometimes, just sitting back and letting things unfold is the very best strategy.

As a lifelong hobbyist, I've personally been through periods of time when I couldn't devote as much time  to my beloved fish tanks...Yet I always had one- fresh, salt, or otherwise. It's just not "home" unless you hear the reassuring popping of bubbles, whirring of pumps, and see the beautiful reflections caused by the interplay of light and moving water.

Of course, there were a number of times that, for one reason or another, I simply let my tanks "run themselves", save an occasional water change or filter media cleaning, and of course, regular feeding (that consisted of tossing in a few flakes or pellets, or whatever was on hand at the time).

You know, putting Mother Nature in control!

A particularly fond memory of this type of  "practice" comes from my Senior year in high school, when I was seriously into breeding killifishes (in addition to keeping saltwater, cichlids, tetras, and of course, the usual high school pursuits of girls, sports, and socializing). As a junior AKA member, I obtained a group of the "Clown Killie", Epiplatys annulatus Monroviae, and was determined to breed the little buggers.

Of course, this species always had a reputation for being just a bit of a challenge, requiring careful care, feeding, and a fair measure of patience. As a busy kid, I had little patience (although more than the average high school guy- after all, I was a fish geek!), so I was delighted to learn that these fishes were thought to fare better in "permanent" and "natural" setups (fish geek code for "set and forget", IMHO).

So of course, in a rather strange twist, I kind of thought that this species was a perfect fish for my busy lifestyle at the time!

I set up 2 pairs and a few extra females in a 2.5 gallon tank, planted (well, packed) with Water Sprite, Hygrophila, and Rotala. Given moderate light from a small fixture, and a sponge filter providing filtration/circulation, this tank looked good and ran just fine with little intervention on my part. In fact, I'm embarrassed to admit that I would sometimes go a week or more without some much as looking at the tank long enough to toss some food in there.


One day (I think it was during Spring Break), I actually took the time to really stare into the tank, to see what was going on...Sure enough, upon close examination, I saw several tiny fry flitting in and among the Rotala! I was elated! Rather than panic and start hatching brine shrimp, I made the very mature and level-headed decision to simply...leave them alone, as I had been doing for months.

I resisted the temptation to net them out, power feed them, and otherwise intervene. I reasoned that I could hardly do better than what they were apparently being provided by Nature, as they have done successfully for eons. ( like, this is a big part of my current philosophy on aquarium keeping!)

I ultimately ended up with a pretty stable population of around 12-15 individuals, in a tank I "maintained" for around 3-4 years. Ironically, the difficulties started when I had the time to really get into "taking care" of the fishes, and took more initiative and control of the breeding.

I ultimately slowly lost the entire colony. Sad.

But a valuable lesson. Sometimes, what we would classify as "benign neglect" is actually the best thing we could do..the closest imitation to Nature that we can offer fishes in captive environments! 

Part of what makes the “job” of the hobbyist so enjoyable is the search for knowledge…the camaraderie that arises from our community putting their heads together to answer great questions…and sometimes, just to share "war stories" with fellow fish geeks. To learn and grow together as a community.

And occasionally, to laugh at our own absurdities. 

Not long ago, I recall walking into my office early one morning, and I immediately was taken aback. I apparently had accidentally messed with the time settings on a lighting app for one of my LED lights while tweaking a color setting (cause, that's what fish geeks do, right?), and caused the light to say on almost 20 hours before I realized that I messed it up.

No biggie, right?

It happens.

Except that I had recently added some cool wild fishes to the tank, after weeks of careful acclimation and quarantine...and then- THIS had to happen, know where I'm going with this?

This is what was going through my mind:

"Omigod, the fishes didn't get any dark period...they've been seriously stressed..."

Now, some of you will say that this wouldn't bother you- but you're totally lying! It would bother the shit out of you, too! I know it would,'cause you're a fish geek. Being bothered about ridiculous stuff is part of what we do!

Never mind that the "delicate" wild fishes had endured the rigors of being captured, traveling to a collection facility, then. a wholesaler, then on to my, THAT shit wasn't stressful enough, right?

And goes what? They freaking lived!


Of course, I relayed this concern to my wife later in the day, when we touched base and asked each other how are days were progressing.

To which my wife, who's absolutely not a fish geek, yet ever the pragmatist, noted, "You know, Scott, sometimes, unexpected things happen in the Amazon."


She was on to something there!

She was right. Everything in Nature, like in society, is not a linear, routine, predictable path. Shit happens.

Yet, we worry, and panic, and obsess...

And it's not just me who freaks out about stuff like this. I know for a fact...

We ALL do. It's like a fish-geek thing.

I think, that as hobbyists, we tend to get caught up in every little minute detail of the little worlds we've created for our fishes- so much so that we often forget the one underlying truth about them: They're living creatures, which have evolved over eons to adapt to and deal with changes in their environment-big and small...or even insignificant, like an excessive amount of light one evening. 

I mean, there must have been some natural precedent for this, right? Some atmospheric phenomenon- or combination of phenomenon-which rendered the night sky inordinately bright one evening at some point in the long history of the world?

Yeah. Exactly.

Think about it more for a second. 

I think that this high level of concern-this "overkill", if you will, on the part of all hobbyists is based on the fact that we take great pains to assure that we've created perfect little captive environments for our fishes, and do everything we can to keep them stable and consistent.

When something out of the ordinary happens- a pump fails, a heater sticks in the "on" position, we forget to feed, etc.- we tend to get a little bit, oh I dunno-...crazy, maybe?

Look, I get it: When a critical piece of environmental control equipment fails (like a heater), especially during a cold spell or heatwave, it could be life or death for your fishes. If you're about to spawn a particularly picky fish or rear some fry, it could be a serious problem. You can't really downplay those concerns.

However, some of the less dramatic, non-life-threatening issues, such as, oh- a light staying on or off longer than usual one evening, a circulation pump stopping unexpectedly for a couple of hours, or forgetting to change the carbon in the filter one week, don't really create that much of a problem for your fishes when you really think about it objectively, do they?


At some time during the existence of our fishes in the wild, there was a temporary blockage in the igarape in which they resided, slowing down the normal flow of water. At some point, there might have been a once-in-a-century cold morning in the tropics, right? At some point, perhaps the swarms of Daphnia or Cadis Fly larvae that were so abundant for months at a time, just weren't...

In most instances, the reality is that the animals that we keep are not so delicate, and the closed environments we provide aren't running so "close to the edge" that we should panic when some random factor changes things up one day.

Again, what I mentioned already bears repeating: When we purchase our fishes, they are unceremoniously netted out of the tank (or stream, lake, river, etc.) environment in which they reside, placed in a plastic bag, transported for who knows how long, and possibly making a few stops on the way before ultimately landing in our aquarium. 

That's a LOT of changes to cope with. Stress.

But guess what? Fishes manage to deal with it. Somehow. 

Sure, our first choice is to have rock-solid parameters and environmental conditions for our fishes 24/7/365, but sometimes stuff happens that throws a proverbial "wrench" into our plans. We have to be adaptable, flexible...just like our fishes apparently are.

So next time your light doesn't come on, or you forget to feed your fishes as you rush off to work some morning, don't stress out over it. They'll be fine. Keep calm. Always keep your concern high, find out what might have went wrong, but don't let obsessing over your fishes keep you from focusing on the even more important things in life (yeah, there are a few, right?).

And remember, sometimes unexpected things DO happen in the Amazon. Sometimes, we don't have the answers for everything. Sometimes we don't have to overthink this stuff. And sometimes, the unexpected can trigger some beneficial- even amazing- consequences. And sometimes, taking a sort of "hands-off" approach is actually the way to go.

There's so much to learn in this much to think about...and too many opportunities to overthink stuff.

It's almost impossible to eliminate any probability of failure in our aquariums, especially when we are dealing with variables like living creatures, dynamic chemical environments, and complex system designs. Even the most simple, "low concept" aquatic display has literally dozens of potential "failure points"- each which could cause consequences ranging from annoying to tragic, depending upon how they manifest themselves.

We just need to learn to relax, look at the realities of what's actually happening in. our tanks, and adjust IF needed.

Stay flexible. Stay brave. Stay curious. Stay thoughtful. Stay calm...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


April 29, 2022


Fresh and new.

I was chatting with someone on Instagram the other day, and he brought up the idea of trying to do a new tank based on____________.  NOT based upon some idea he had in his head. NOT based on a wild habitat which he saw. NOT even based on a plant or a fish or a rock that he wanted to work around...Nope. He wanted to do the same thing as some other guy, and to be able to garner all of the cool "accolades" which accompany a tank going "viral" or whatever.

Oh, and it HAD to be "amazing." (his words)

I was like, "Dude- do what you want...but the emphasis should be on the 'what YOU want' part.  Not what people on social media would find 'cool!' Don't fall into that trap..."

My usual schtick. Yeah.

I was simply dumbfounded that creating a near duplicate of someone else's tank he saw on social, for the expressed purpose of getting more attention on social was the entire "goal" for this tank build. And, that he was putting all this pressure on himself to "match" or "exceed" the that work he was essentially copying. Like, WTF?

Of course, it wouldn't be productive or even fair for me to simply trash the guy, I needed to help him understand how he was doing this to himself. On one hand, if you're trying to endear yourself to the "Every tank that looks like_______ is awesome!" crowd, this was a perfect recipe, I guess. On the other hand, when I pushed back, he did kind of sheepishly admit that this was a bit silly...and that he was a bit "burnt out" on what he was up to in the hobby at the moment.

Ahah..."Burnt out."

Heard that one before.

Of course, then the conversation briefly turned to ways to overcome this "burnout" that he and others sometimes fee within the hobby. While it's always possible to get "burnt out" even on stuff you love, I think that it's exacerbated by doing work which doesn't truly speak to you. Doing it for the wrong reasons. Or getting way over your head for something which isn't really what you want to do.

I guess "burnt out" is the wrong descriptor...More like, "benignly disinterested." It can be doing stuff that's actually interesting to you! Yup. Besides just doing stuff that speaks to you, I think the other key is to do a diversity of things which interest you at one time, when possible; to explore multiple "disciplines" within the hobby. Do more. Do different. Scratch the itch...

I love the idea of keeping a few different types of aquariums at any given time, if it's possible. I mean, it's a privilege to just be able to keep one aquarium. However, when you have the means and ability to keep a few tanks, not only does the real magic start happening, you have multiple avenues to direct your passions and energies. I like to keep tanks from different "disciplines"; in my case, blackwater/botanical, "evolved" brackish, and a coral tank.

There are real advantages to having tanks from various hobby sectors in play. First and foremost, if you should ever find get just a bit less stoked about one particular tank (or type of tank, in my case), you can focus on the one that speaks to you at the moment. Tweak the others when you feel more interested in them. It keeps you alive.

Keeps things fresh.

Staying fresh is quite important. The hobby is supposed to be fun, and I suspect that, for an increasing number of people, it's becoming more of a "chore" than anything else. This wasn't the first conversation I've had with a hobbyist who was feeling what this guy was feeling: A source of  self-inflicted pressure to do stuff...To "produce." 

And yeah, I DO think that this "pressure" is a direct "by-product" of social media. A human desire to be "accepted" as part of the "cool kids." And I think that's resulted in a lot of hobbyists getting a bit off course, and doing and sharing (or feeling compelled to) stuff that really doesn't resonate within them. I'll tell you one thing, this "pressure" has resulted in a large number of awfully similar tanks popping up on the 'gram and elsewhere...

I've commented about this before, but my Instagram feed is becoming a shockingly bland and replicative place. A see of sameness. I see literally dozens and dozens of aquariums done up in the same rigid "style", with the main differentiator being either how many sexy potted plants are on the shelves surrounding the tank, or perhaps a slight variation of the way the wood breaks the water line, or how many "Hakkai stones", "Frodo stones", or whatever the trending "rock du jour" is comprising the hardscape.

If I see one more breathless, "What fish do you think should we put in this new 'mini Rotala' tank!?" pseudo-tease post (when the reality is that they were always going to put in Rice Fish, Ruby Tetras, or White Clouds regardless.Who the fuck sets up a tank with no clue at all what they want to put in it? C'mon...), I'm going to vomit. And don't get me started on the copycat sterile-clean, ridiculously over-diverse, almost artificially "Nature Style" marine macroalage tanks which are starting to become the latest aspirational wet dream of every uninspired hobbyist looking to increase his following count and tag potential "sponsors" in his posts. 

Whatever happened for doing what resonates with YOU? 

I want to metaphorically beat the lameness out of you. Of course, maybe you really DO enjoy exactly copying someone else's tank. It's what you like.


I mean, look, if the "macro algae clean room fantasy masturbation tank" is your thing, do it. If you really love "ADA Black Root" and "Old Mountain Stones" or whatever, and they make your heart sing, use them. Don't let me shame you away from doing what you truly want to do. Where I WILL nudge you is when you want to do it for some crazy-ass reasons, like we just discussed. That's just not healthy. 

Doing something just to stand out from the crowd is a weird goal, too. But doing what you like- even if it just happens to be a bit different from the prevailing trends, truly stands out. For the right reasons.

What tanks actually DO really stand out to me hese days?

Well, it's not necessarily ones that use different materials or whatever. It's the ones that reflect a different approach. A story. Something which doesn't feel like it's trying to go over the top and out-create the (obvious) original inspiration, or match up to some hashtag-friendly trend, "just because." Something which feels authentic, because it comes from the heart of the creator, not from the Instagram feed of some aquascaping content aggregator.

The ones which truly stand out are standing out for a reason: Because they're unique, fresh, different. They reflect the interest and aspirations of their creators. They don't try to be "something", other than what they are. They don't need a fucking stupid name ("Heavenly Dawn ON the Hill of Light" or whatever) to "classify" them or give them "legitimacy."


Screw trying to get "picked up" by the aquascaping content aggregators on social media networks. Screw trying to get "likes" and 💕 and all of that shit. Just do something that you like and share it to inspire others to share their own unique work. Not another copy of yours. 

And there is another, sure-fire "trick" that can help you be happier in your own lane as an aquarist...

Think like a beginner.

Yeah. Really.

Beginners have this "thing..."

Perhaps the beginner knows something we don't.

I think I- we- that is, more "advanced" hobbyists...know too much. 


And I don't mean that from an arrogant perspective or anything.

I think that so many hobbyists at our level of experience tend to overthink every aspect of the aquarium hobby. We carry "baggage." We worry about what the crowd on Facebook or Instagram thinks. It's quite evident- particularly during the new tank startup phase...Almost no one shares the earliest, dirtiest days of their new tanks. We feel the need to "prep" it for the masses. We don't feel it. Rather than just letting ourselves enjoy the moment- the wonder, and the awe that comes from doing something special, beautiful, and, let's face it- incredibly cool- we worry about shit like "presentation."

I mean, setting up a slice of Nature in your own home? 

Shit, that IS something amazing, huh? 

Something that nine-tenths of the world will never get to experience or even comprehend.

We should know that. We know a lot of other stuff, so...

Perhaps- just maybe...we know too much.


We understand all of this stuff that's going on in our tanks. Yet, for some reason, many are afraid if it's a bit different than, or doesn't meet someone else's expectations. We worry about "them", because they might not approve...

Fuck "them."


We, of course, worry about our dream tank not being in the perfect state of awesomeness at all times, ready to show on Instagram Live, or whatever....

We stress about algae or cloudy water, or whatever.

Outright beginners actually have it much easier in this regard, I think.

I mean, when just having a glass or acrylic box of freshwater or saltwater filled with fishes in your home is a novelty- a cause for rejoicing, that's the magic part. As a beginner, you tend to live in a bubble of gentle "ignorance" (eeehw- that's kind of harsh)- okay, let's call it "blissful lack of awareness about some things" that, to most experienced hobbyists, some of this stuff can really suck, and is a source of shame for some reason.


And that is actually a beautiful thing- because, unburdened from this junk, a beginner is taken by the sheer wonder- and joy- of it all. They don't stress out about stuff like algal films, detritus on the substrate, micro bubbles and- oh shit- the occasional out-of-place piece of wood in their aquascape. Shit, they likely don't really care what KIND of wood it is, either. They're not worried about that, or any other of a dozen minutiae like we are, because they don't KNOW that it's a "problem." 

They're not "handcuffed" by their past experiences and the knowledge of having set up dozens of tanks over the years. Rather, they're just stoked as shit by the thought of Glowlight Tetras, Amano Shrimp, Glass Catfish, and "ultra-common" Bettas taking up residence in the new little utopian microhabitat they just set up in their New York City apartment.

What about us- the so-called "advanced" or experienced hobbyists? Can we liberate ourselves from this hell of our own creation?


I think it's entirely possible to release ourselves from the "burden" of our own experience, and to allow ourselves to enjoy every aspect of this great hobby, free from preconception or prejudices. To just make decisions based on what our research- gut, or yeah- I suppose, experience- tells us is the "right" thing to do, then letting stuff happen, and accepting it.

Not to waste any energy worrying about how many damn "likes" our next tank pic gets.

In other words, taking control of the influence of others, as well as that our own experience, rather than allowing it to taint our whole journey with doubt, dogma, second-guessing, and over-analysis of every single aspect. Don't get high on the accolades, or pissed off about the criticisms which others may levy. 

And relaxing into it. Enjoying engaging in the hobby for YOU.

Embracing the sheer joy of being a beginner. Again. it's exciting. It's fresh. It's healthy. Even if you're doing more "advanced" stuff...

Let go. Don't do stuff in the hobby to please others...that's a recipe for misery, trust me.

Do stuff that's fresh, new, and yours.

Stay creative. Stay resourceful. Stay inspired. Stay original. Stay bold...

And Stay Wet.


Scott Fellman

Tannin Aquatics 



April 25, 2022


The crowd? Or just the community?


One of the great things about being in the aquarium hobby for a lifetime is that you have numerous opportunities to learn things, acquire new skills, sharpen old ones, and to occasionally re-think stuff you thought was not even questionable in the past.


For example, stocking our tanks.

When it comes to stocking aquariums, I've historically been extremely conservative, erring on the side of under-stocking, and simply leaving a a lot more room for additional fishes in most of my systems over the years. I would often be teased by friends about how "empty" my tanks looked, lol.

I think that part of this conservative trend comes from my aquarium upbringing. My dad bred fancy guppies, and was himself brought up following the teachings of the legendary masters of the guppy hobby, like Hahnel, Sternke, and Alger, who advocated moderate stocking of their guppy tanks, for a lot of good reasons.

I grew up reading all about them as a kid in my dad's old aquarium books, and applied their ideas to my work, too.

Some of my attitude towards stocking was based upon the technology I grew up with in my earliest days in the hobby. Inside corner filters, outside power filters, and under gravel filters were thought to have a rather limited "capacity"...for what, I'm not exactly certain, but nonetheless, I followed the "rules of the day" when it came to common sense stocking.

Of course, when I was a teen, we had the dawn of the modern reef aquarium hobby, and its evolved practices and technology, which I have since spent decades playing with. The advent of trickle ("wet/dry") filters, evolved protein skimmers, and the practices of utilizing live rock and sand in reef tanks changed the game. A marriage of biology and technology as never before. It kept evolving to this day with sumps, calcium reactors, dosing systems, LED lighting, and now, with automatic filter rollers.


Suddenly, not only could you keep delicate organisms like stony corals alive, you could keep more of them, because of the practice of building up an ecosystem- a "biological infrastructure", if you will- which included a heavy reliance on beneficial bacterial populations and managing the specific physiological needs of these organisms.

I was still a bit conservative in stocking for quite a few years; typically massively over-building nutrient export mechanisms and practices into my systems. They definitely served me well, even though, looking back, I think I was traversing deeply into "overkill" territory!  It wasn't until quite recently that I really began to question why I was so conservative, and for what reasons. "Cleanliness" (for want of a better word) was, for many years, seen as the way to get great results.

The reality of this over-simplified mindset on near-sterility eventually made me realize I was wrong. When I was a partner in a coral propagation facility, early on it became increasingly obvious that the desire to literally polish the shit out of the water had the opposite effect on the corals. We were simply making the water too "clean!" Only when we allowed some nutrients to accumulate, and relied more on natural processes than "technology overdrive" did our corals start to really thrive and grow faster.

And, this definitely had an impact on my freshwater practices.

In 2015, when we started Tannin Aquatics, we pushed heavily on the idea of using botanical materials to help create a functional biome- an ecosystem- to facilitate nutrient processing and supplemental nutritional resources for our fishes and other organisms that reside in our tanks. I spent a lot of time studying and researching the wild aquatic habitats which enthralled me. Married with a more "holistic" approach, which views the aquarium itself as a "filter" of sorts, my conservative approach to stocking began to evolve and liberalize considerably!

So here we are today, with me talking about a totally different mindset on stocking your botanical-method aquariums. I needed to provide you with that brief history of my hobby experience on the topic to provide some context, and to reassure you that I'm not just some asshole telling you to "stick it to the man" and blow off a century of aquarium hobby "best practices" just..."because!"

Now, before I get into the meat of today's topic, let me clarify a few things. I am NOT calling bullshit on the idea of common sense in aquarium management. I am NOT advocating that everyone fill their10-gallon starter tank with 50 Neon Tetras, or other equally stupid things. 

I am still a firm believer in NOT over-stocking your tank.

I just think that the "limits" are farther out than we have previously assumed. Yeah, I wonder, what exactly is the definition of "over-stocking" anyways? Is it a sort of subjective thing?  Or, some hard-and-fast "number?" Is it a tank that simply looks ridiculously full of fishes? Or is it a "thing" that is determined by water quality (ie; nitrite, ammonia, nitrate, phosphate, etc.) or other environmental factors which are measurable (pH, conductivity/ORP, dissolved oxygen levels, etc.)?

Likely, the latter.

I don't profess to have the authoritative answer to every aspect on this topic. I can only share what works for me; where I've come from, how I reached this point, and what it has done for the fishes which I keep. Again, there is likely as much subjectivity as there are obvious answers to stocking methodology.

I mean, on a superficial level, there is not a lot of difficulty in calling bullshit on the idea of stocking a full-grown Clown Knifefish, a large Pleco, and an adult Oscar in a 20-gallon aquarium, right? The physicals pace and physiological ability of the tank to support that much life is obvious. The amount of metabolic wastes they produce would literally overwhelm virtually any practical filter or biological processing system which you could attach to such a tiny tank, in hours. And not to mention, it's simply cruel to keep these fishes in a tiny space like that..sort of like having to spend the rest of your life in a closet with 3 adult strangers!

This kind of overstocking should be obvious to all.

And I'm not talking about trying to stuff 80 Mbuna in a 50 gallon tank, or whatever. Fishes which have significant space needs because of their territorial behaviors or "pecking orders" typically don't play well with this concept. I've heard the theory that the "overcrowding" lessens aggression or whatever... I disagree, as substituting once stress for another is not a good thing.

What I'm talking about specifically here is figuring out how many small (and by "small", I mean fishes that are 1"-1.75" or so in length, like characins, Rasbora, etc.) can be kept healthily, humanely and safely in that same 20-gallon aquarium. 

Consider fishes like characins. Okay, the small ones, like Hyphessobrycon, Hemmigrammus, etc. Not fucking Pacu or Piraniah, etc. 🤬

How much metabolic waste does a fish that weighs a gram or so actually eliminate into the aquarium on a daily basis? I'm sure there is a study of that...somewhere. I'll bet that if we knew the actual numbers, a lot of minds would change on stocking. 

Of course, there are also the most banal of considerations when talking about more densely stocking your, aesthetics. I mean, do 50-100 fishes of ANY type and size look good in ANY type of aquarium to you? Do you actually WANT that many? Or, can you afford that many? I mean, 100 Tucano Tetras, for example, can set you back a serious amount of cash!

But yeah, lets stay on the general topic of characins....

Many of these little characins occur in large shoals or schools in Nature. That's how they live. They've evolved to live that way. They feed together, shelter together, and spawn together. As a community group. They are often gregarious and social, and display their most natural and healthy behaviors when kept in such groups. They feel safer that way. These little fishes are almost like a single, communal organism!

They will generally simply fail to thrive, or at least, be at their best- when not kept with a significant number of their own kind in an aquarium setting. There is a legitimate reason why keeping 1 or 2 Cardinal Tetras in a so-called "community tank" is just not good. You're often told to keep "at least 6-10 specimens or more together" for them to be at their best.  

It's the "or more" part that intrigues me, of course. It's logical. There is a reason for that, as we just discussed.

They live in large groups in Nature. Fact.

I mean, yeah, you're limited by the size of your tank, 'cause it's not the Igarape Dracua in Brazil or wherever. It has no large water "flow through", or a vast supporting terrestrial ecology. It has different external environmental inputs, and a finite amount of water. So your job as an aquarist is to find that "sweet spot"  which provides your fishes the ability to live their lives in social and physical comfort, while maintaining acceptable water quality. That means keeping them with a significant enough population of their peers to meet their needs, while keeping water quality and health at optimum levels.

I actually see this challenge as a call to simply add more fishes to our tanks, when permissible, and to create environmental conditions appropriate for them to thrive.

The two need NOT be mutually exclusive.


Now, look, once again, this is not a call to run off, like the proverbial "headless chicken" to the LFS and buy 300 Cardinal Tetras for your 50-gallon tank. That's just dumb. It IS a call to consider if that 50-gallon tank can be created and managed in such a way as to responsibly provide a healthy, sustainable home for say, 50-75 of those same Cardinal Tetras. 

I think that it can be. And this is not one of those things that I'm pushing out to be "in your face"; to garner those comments like, "Sure you CAN, but why WOULD you?"

It's not like those, "I do THIS and never do water exchanges!" kinds of asshole-like ideas which provoke nasty discussions on forums and Facebook groups. I'm not advocating some sort of "workaround" to best Nature here. I'm advocating looking at what occurs in Nature and figuring out if we can replicate some aspects of it in the aquarium, for our fishes benefit.

It's about creating conditions to maintain appropriately-sized populations in our aquariums. Now, sure, there are studies out there of wild aquatic habitats and their fish population density and diversity, where transects of wild habitats have been conducted, which, if you do some algebraic calculations, could yield some approximate numbers of fishes of a given species per a given area. Again, as I just alluded to, there is more to it than just "X" fishes per square meter", or whatever-but it is a starting point, right?

I mean, if the fishes have so much room in Nature, why do they congregate together in such large numbers in a small area?

You need to take into account your ability to provide an aquarium environment and maintain husbandry practices which can facilitate more dense population of fishes. I don't take this responsibility lightly. You shouldn't, either.

I am an extremely careful feeder, believe in good oxygenation and I am a champion of significant nutrient export (ie; water exchanges and use of biological/chemical filtration media, etc.) in all of my tanks.

The idea of building up a substantial (okay, let's change the adjective to "significant") population of little characins was something I'd always wanted to do over the years. However, I spent way too much time buying into "conventional aquarium thinking" and limiting myself to "1-inch of fish per gallon", or whatever the prevailing "guidelines" were at the time, to even think about challenging that.

And then, over time, I sort of started thinking about the rationale we employ for limiting stocking in aquariums: To create environmental conditions conducive to fish health. I realized that there is more to it than just listing the numbers of fishes. I believe that  you can actually have way more than the "one inch of fish per gallon" thing and still provide optimum environmental conditions...if you understand what those are for your fishes, and make achieving them part of your whole system from day one, and husbandry routine thereafter.

So, as I built up my population of 70 small characins in a 50-gallon tank, it occurred to me that it works because I do the things necessary to make it work. You can't have a large population of fishes in a given tank size without proper circulation, filtration, a water exchange regimen, and careful feeding. Give-and-take. Like everything in this hobby. You can't "have it all." But you CAN have most of it! If you're flexible and willing to compromise.

I firmly believe that a botanical method aquarium, with its significant and well-thought-out emphasis on ecology, is the perfect starting point for a densely populated tank. As I've shared with you often, my thinking has long been that you should actually consider the tank itself (or more properly, the botanical environment within it) as the"biological filter", and simply use aeration/surface skimming and/or circulation pumps to facilitate the gas exchange.

After almost 25 years of playing with this botanical stuff, I'm convinced that the microbiome provided by a properly set up and managed botanical method aquarium provides a huge amount of biological support for the fish population. Not exactly revolutionary, of course- but an idea that's often overlooked today.

Think about this:

The botanical materials present in our systems provide enormous surface area upon which beneficial bacterial biofilms and fungal growths can colonize. In addition to physically fragmenting botanical materials, these life forms, collectively referred to as "epiphytes", utilize the organic compounds present in the water as a nutritional source. They also provide supplementary/primary food sources for a huge array of organisms within the aquarium itself, including the fishes.

Just like what happens in Nature.

In the case of our fave aquatic habitats, like tropical streams, ponds, and inundated forests, epiphytes are abundant, and many fishes will spend large amounts of time foraging the "biocover" on tree trunks, branches, leaves, and other botanical materials.

The biocover, as I just mentioned, consists of stuff like algae, biofilms, and fungi. Nature's "filters." Although most fishes use leaves and tree branches for shelter and not directly as a food item, grazing on this epiphytic growth which occurs on them is very important. You're unikely to have fishes in an aquarium decimate all of this growth, so a sort of "balance" is achieved.

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

These organisms also provide a sort of "onboard nutrient processing" service for the aquarium in which they reside. A "filter", if you will...but one with a "feature set" and capacity far in excess of most commercial filter systems you can buy. It's free, and super reliable.

You just need to give it what it needs in order for it to work.

So, like, your filter is almost "supplemental" in this role, really. Think about it:  In most filters, you're trying to recruit bacteria and other microorganisms to help process metabolic wastes from your fishes. Well, as we just alluded to above, the biome within the aquarium itself does the bulk of that work, really.

The type of filtration, or more important, the quantity of filtration, and the way in which water is returned- together play a huge role in supporting a significant fish population on a long-term-sustainable basis. No real magic here. Nothing new..except a different understanding of the role that the "filter" plays in the aquarium.

Your aquarium should have some water movement, to facilitate gas exchange, provide a little "exercise" for your fishes (that sounded stupidly quaint, but you get the picture), and to avoid the formation of thermal, pH and/or nutrient layers in our tanks.

Gas exchange (the process in which carbon dioxide exits into the atmosphere and new oxygen from the atmosphere is dissolved into the water) is really important in aquariums, and aeration from filter returns helps facilitate the process. Fish need oxygen (like 5-6 parts per million) in their water. Now, it's not mandatory to have airstones, filter returns, or surface skimmers to create surface agitation, but it sure helps, particularly if you keep a large population of active fishes! 

I suppose you could say that the "purpose" of aeration is to "break up" the surface of your water. You’re not going to separate the oxygen molecules from the water and force a gas exchange within the water column, by cranking up an ayirstone- that's not what it does. But it will help break up the surface boundary layer to facilitate gas exchange. I guess that's why I love surface skimmers, or filters which skim the surface boundary layer. They just make the gas exchange process easier and more efficient.

And of course, simply choosing an aquarium with a large surface area is important and beneficial, too. Wider, more shallow tanks are always better than tall narrow ones at this.

What about foods- and the way we feed our fishes? 

Feeding is, of course, very important. As is the type of food, the frequency, and the amount dispensed.

As a long-time proponent of primarily feeding frozen foods to my fishes, I realized that frozen is not the panacea that it seems to be. Sure, there are certain benefits to being able to feed fresh stuff like brine shrimp and worms and things in a convenient fashion. However, frozen foods also often have a significant amount of organic material- stuff you may not want in your tank- with the food as a part of the process of manufacturing them.

The "juices" contained in them, which, when added to the aquairum water can lead to accumulations of nitrate and phosphate- the "enemies of high water quality"- within the aquarium if you're not especially fastidious. It's easy to literally "kill your fishes with kindness!"

I think that, if you're trying to push the fish population a little, careful, non wasteful feeding becomes really important. This would necessitate a change to other foods- like pellets. Yeah, I admit, I used to hate pellet foods. I thought they were sort of nutritionally-defficient "kibble" for fishes. And most of them were- back in the day!!

Fast-forward to now...There are some amazing, super high-quality, highly nutritious pellet foods out there which are easy to feed, contain almost no fillers or non-nutritious ingredients, and which are easily digested, encourage more uptake of nutrients and less metabolic waste, and can be fed in such a way as to assure that less goes "down the drain" as opposed to in your fishes' mouths.

Can you still use frozen food in a more densely-populated tank? Of course! I do! Just be more careful. Don't feed it every single day, multiple times a day, in large amounts.

Little compromises. Changes in the way we do stuff. We know how to work with that.

And one other thing...You won't just dump the entire population of your fish into the aquarium from day one, right? I mean, you shouldn't. At least, not without some preparation. You need to allow the resident beneficial bacterial/microbial population to build up to handle the increase in metabolic wastes produced by the fish population.  Slow advance of adding the fishes.

Okay, building up a population of beneficial bacteria to tackle the metabolic waste products produced by your fishes is decidedly conventional  aquarium hobby thinking. And there ARE some (oh, shit...) "hacks" that, in theory and practice, could make it possible to add a LOT of fishes from the "get go". Intrigued? Well, you know the "hack" I'm gonna talk about. It's called, "pre-stocking." It's pretty straightforward, but it requires time. And patience! (shocker, I know. Only my "hacks" would not really be "hacks". Or not "time-saving" ones, at least...)

Here's the deal:

Set up a botanical method aquarium with a large number of leaves and other botanical materials and substrate from day one. Inoculate with live bacterial cultures (PNSB and/or Nitrobacter/Nitrosomanas). Throw in a bit of fish food if you want. Stock with organisms like Daphnia, Cyclops, Paramecium, etc. Let the tank "run in" for several weeks, or a month or more if you can handle it (you can). This will give the microbiome and overall ecosystem a chance to literally arise and "assemble itself" before the fishes are added!

Then you could add most, if not all of the fishes at once. Seriously. 

Is there a risk to this? Well, sure. Working with live animals in a closed aquarium always involves some risks. No guarantees. You could still lose fishes. And you still need to monitor nitrite and ammonia, and to understand the concept of the nitrogen cycle. You need to be aware and do a little work. I've done this exact thing literally several dozen times in the past 20 or so years, including just a few weeks back, BTW) and have never, ever had either detectible ammonia or nitrite, let alone a "cycle" after adding the fishes. Other than a few "jumpers", I've seldom lost a fish to this process.

Yeah. I'm no fucking visionary. And I'm not the only hobbyist who's done this. Plenty of botanical method aquarium enthusiasts employ this  same practice with similar tremendous success. I mean, it shouldn't be a real surprise, because it's not really a "shortcut."  It's not some "miracle." It takes time!  That's the compromise you have to make. You're simply establishing the ecology and the nitrogen cycle within the tank before the fishes arrive. "Fishless cycling" as the process is known, but with a botanical-method twist and it's associated benefits!

This is also nice because it slows you down ahead of adding the fishes, and gives you time to acclimate and quarantine all of your fishes before releasing them into the display aquarium. It also has the advantage of starting your fishes in an aquarium which is, by many hobby definitions, very well "established" before they're ever added! Other than the "adding most of the fishes at once" part, it's actually not all that different from gradually stocking a tank over  time, except that a more robust ecology was in place and operating long before the fishes arrived.

And of course, you could employ the same mindset, yet gradually build up a fish population anyways- perhaps for other reasons- like getting the more timid fishes settled in first, before the active, crazy ones, etc. Apply it in a manner that works for your situation.

And of course, perform regular water exchanges on your aquarium. Make them a ritual. Regardless of how comprehensive the ecology in your tank is, it's not an open, natural habitat.  It requires proper care. If you're going to ply new territory, don't abandon all of the tools that got you there in the first place. You're smarter than that. I know that you are!

So yeah, THAT is how I have 70 healthy, happy, and active little fishes in my 50-gallon aquarium. I didn't "cheat." I didn't create some dependency on a huge and absurdly complex commercial filter system, or some magic elixir. I'm not slave to massive water exchanges daily. All I did was think about how ecology works in aquatic systems, partner up with Nature, deploy all of the things we've talked about in our botanical method aquarium work for years now, and provide the optimum conditions to allow a (dense) population of fishes to thrive from day one in my tanks.

I compromised when required, and understood many of the nuances involved in keeping large groups of fishes. I studied what occurs I the wild and figured out how to make it work in my aquariums.

You can, too.

It's literally another mental shift. An example of looking at things from (as we say here) a slightly different perspective...

Again, some of you may disagree with this approach vehemently. Some of you may be like, "WTF, Fellman. Freaking irresponsible." Some of you might shrug and say, "Okay, yeah. Whatever. So?" A certain percentage of you might have already thought like this. A smaller percentage may just give the approach a try in the future.

I encourage you to do what you think is best for your fishes.

Regardless of how you stock your tanks, study some of the science behind it. Understand the nitrogen cycle, and the importance of building up an ecology in your aquarium. Shift to considering the entire aquarium a miniature ecosystem, capable of supporting a vast array of life at many levels. Study the needs of your fishes, and figure out the best way to meet them.

Don't take shortcuts for the sake of "gaming the system" (ie; Nature). The "system" will simply kick your ass (and kill your fishes in the process). Don't just take my words as "gospel" here, nor the guy with 40,000 followers on YouTube, the Instagram "influencer", or your cousin Brian.  

Think it through for yourself. 

Responsibly experiment.  That's really the only way to advance this hobby. 

Sorry, Brian.😆

Stay curious, Stay bold. Stay thoughtful. Stay experimental. Stay logical. Stay grounded...

And Stay Wet.


Scott Fellman

Tannin Aquatics 




April 21, 2022


Finding your own lane: The real "Mental Shift!"


Okay, I"m going to use the phrase, "mental shift" for like the 30,000 time here in the last 7 years, but I think that it's pretty important. 

I've seen several friends and fellow hobbyists "find their lane" in the aquarium hobby lately, and it's been truly remarkable to see. Watching others be delighted by things which they might have never even considered, and then seeing how they resonate, is an amazing thing. Truly inspiring.

I was looking at my latest botanical method aquarium the other day, and literally admiring the fungal growth and biofilms emerging from the wood, and lightly coating som of the leaves on the surface of the sedimented substrate. I was savoring the tinted water with a slight "haze", likely the result of a combination of super fine constituents from the substrate, and some organics from the wood and leaves.

And I though to myself, "Damn, this one is looking perfect!"

How far I've come, to the point where what many consider absolutely horrifying and aesthetically nightmarish, is to me, an amazing expression of Nature at it's most authentic. Like, I remember setting in the wood and such in the first days of this tank and being sort of repulsed by how harsh and sterile it felt before the wood was colonized and the water began to tint up and go slightly turbid. It felt...I dunno- a bit "unnatural."

Minutes later, as I was scrolling through what I could only characterize as the bland "sameness" of all of the perfectly manicured, spotlessly sterile-looking "Nature Aquariums" which seem to populate my Instagram feed, I once again had that realization about just how far I'd come as a hobbyist, in terms of what I find compelling, interesting, and attractive. 

To me, there is sheer joy in seeing the things which arise in wild aquatic habitats (biofilms, fungal growths, decomposition, etc.) occurring in my tanks. It's like a little victory when Nature makes Her appearance! I find myself watching videos or glancing at images of the wild aquatic habitats which inspire me, and feeling this incredible sense of satisfaction at the parallels I've experienced- at the "blurring of the lines" between Nature and aquarium that I helped foster.

Now, that's not to say that I don't enjoy looking at the work of the many talented aquascapers out there who specializing in the artistic, highly conceptual stye. I appreciate a beautifully done planted aquarium, Iwagumi, or rocky hardscape as much as anyone. Hell, I've gone so far as to state that if one of my "superstar" aquascaping friends pops into Los Angeles for a few days, and wants to set up one of these tanks up for me in my home, I wouldn't complain!

I just have no desire to do one myself. None whatsoever.

I've found my lane. 

I know what speaks to me; what I enjoy, and why.

That's really powerful. It feels great.

After a lifetime in the aquarium hobby, I've found  the things which I like, and practice them without concern about what anyone thinks, or how I will be judged, or the type of armchair analysis that my aquariums will be subject to. To put it in rather simple, direct terms, I simply couldn't care less what others think of my work. I do it for me. Oh, and to push the limits of the botanical method. And if it inspires other hobbyists to do similar things, that's a huge win.

This is a very healthy attitude for everyone to embrace. I barely hear the accolades we receive for this stuff, and completely disregard any negative comments. Tell me that what we do is "stupid", and "ugly", and "sloppy." (All "criticisms" which I've heard over the years...) I just don't care. I cannot stress this enough. I will, however, push back when someone makes a comment which incorrectly implies that what we do is messy or reckless or dangerous or whatever, because it's just plain wrong. We don't want people perpetuating incorrect information about this stuff.

Those kind of "criticisms" from those who have limited knowledge of a subject, yet feel compelled to shit on others, have for years thwarted hobbyists from trying things outside of the "generally accepted norms", and it's time for that nonsense to stop. Perpetuating myths about various hobby topics which the "critic" has no firsthand experience with hurts everyone. Regurgitation of misinformation is damaging. I see those negative comments as opportunities to educate people about what we do, and why it is incredible...

We all should.

In today's "Insta-famous" world of viral videos and over-the-top ideas, where everyone fancies themselves an "influencer", it's nice to feel that sense of comfort that you get when you know that you're doing exactly what you love the most. I hope that every hobbyist can feel this! It's satisfying, liberating, and incredibly enjoyable.

It's healthy.

Besides, if everyone is an "influencer", who's actually doing stuff? 

I get a lot of questions from hobbyists of all ages who are intimidated or concerned by "them" or "they" on social media. Worried about how their work will be received and analyzed. Hobbyists who are held back because they feel that the comments and criticisms of others are going to somehow "ruin" them.

That's unhealthy.

Realize that, when you're doing exactly what you want- what you love- that none of this stuff matters. Criticisms will keep coming...

I experienced this a lot in the early days of Tannin Aquatics. A number of people literally told me that the idea of utilizing all of this botanical material to replicate habitats like the igapo and varzea and such in closed systems would lead to polluted tanks, wildly fluctuating environmental parameters, and fish death.

Having created numerous systems based on the concept over the years, I pressed on- stubbornly. Because I knew that there was merit and benefit to what I was doing. And, thanks to all of you- the brave hobbyists who also shared our vision- we've seen a worldwide renaissance in the idea of utilizing botanical materials to create functional habitats in our aquariums.

It would have been so easy to just fade away if I listened to the negativity.

But, hey- this is not about me and how cool I am. That was just a personal example of this phenomenon!

I've written about this "negativity" stuff before over the years, and still talk about it in in my lectures, because it's an issue that doesn't always seem to go away.

Why? What causes people to criticize and discourage others so strongly in this hobby? It's kind of weird...

It's like there are some people who simply feel compelled to sabotage the well-intentioned, yet progressive efforts of others. It's like they're afraid to see others succeed or change what's become comfortable for them. I imagine this is what people felt when they first introduced TV and people didn't want to give up their radios, or whatever.

Yeah, I can't help wonder if it's fear. Really.

Fear of change. Fear of not being "the expert" on something. I'm not sure. But it's a thing we have seen many times in the hobby. It's usually just a few loud people, but they can do surprisingly large amounts of damage thanks to the utility of the internet and the power and reach of social media.

So, what's the "antidote" to this nonsense? 

Just don't listen to the noise.

And for those of you who are pioneering new ideas?

Look, there is always someone who has to be the first to accomplish something great and new and different. Someone who can overlook the negativity and "smack talk", to fly in the face of convention while taking that road less traveled. Someone who has to shake off the "taboo" fears created by others. To move forward, despite the "criticisms."

This is how we progress. This is how we will continue to progress in the hobby.

And more important, this is how we inspire a new generation of hobbyists to follow our lead, for the benefit of both the hobby and the animals that we enjoy. Nor can we dispense advice to fellow hobbyists with a dogmatic attitude that discourages progress and responsible experimentation. It will simply stagnate the progress of the hobby we all love.

Just be you. Be cool. be authentic and honest. 

I’m not advocating the abandonment of common sense and healthy skepticism. Everyone should not make a mad dash to the LFS to assemble schools of Black Diamond Stingrays.

What I AM pushing is that we (and by “we”, I mean every one of us in the hobby) should encourage fellow hobbyists who want to experiment and question conventional wisdom to follow their dreams. If someone has an idea- a theory, and some good basic hobby experience, there is certainly nothing wrong with that. Yes, there is the sad fact that some animals might be lost in the process. It sucks. It’s hard to reconcile that…and harder to stand by it when animals are dying.

However, that may be the cost of progress.

The cost of not progressing might be far higher: The loss of countless species in the wild whose habitats are being destroyed, while those of us with some skills, dreams, ideas, and respect for the fishes sit by idly -watching them perish, failing to even attempt captive husbandry and propagation for fear of criticism and failure from the masses.

There has been very real talk over the years about making the importation, and possibly the distribution- of live corals and some fishes illegal in many nations. It's not that unrealistic a possibility. Who knows what opportunities might be missed if we fail to even persue our goals?

So, yeah. it's bigger than just not wanting to post pictures of our new tanks on Instagram or whatever. for fear of criticism. Not making the biggest mental shift of all- the one which enables you to find-and stay- in your own lane- creates a vacuum of progress and progression which can cause stagnation.

So, don't fear the criticisms. Don't worry about the naysayers. Don't fall for the negativity. Don't be discouraged. Ever.

Stay bold. Stay strong. Stay committed. Stay thoughtful. Stay creative. Stay in your own lane...

And Stay Wet.


Scott Fellman

Tannin Aquatics