March 12, 2019


Can it wait?

There are things in this hobby which we never really understand, but that predictably drive us crazy. And there are those things that arise, which we have to handle, that annoy, disturb- even scare us.


The motor in your canister filter is making that familiar chattering sound- you know, the one that means the impeller needs to be taken out and cleaned. And of course, that means shutting it down, removing it, cleaning it, reinstalling it, and getting it primed again. You sort of located it in the part of the aquarium stand that's hardest to access...And you remember from the last time what a pain in the ass it was to do this...

Can it wait a bit longer? Is the chattering noise that bad?

I mean, you're not loosing any circulation or's just that the sound is a bit...annoying...and...

Some stuff that you need to face with your tank is more than just a pain in the rear- it's the kind of thing that disrupts the entire fish population until it's completed. That overgrown stand of Cryptocoryne wendtii really needs to be thinned out before it takes over the whole right rear of your tank!

And it's badly encroaching on that rare Red Crypt from Borneo. And of course, it's growing behind that insanely cool stack of driftwood that you finally got to hold position after 2 hours of frustrating effort, and the 'scape has been just perfect ever since that day! Thinning out this group of plants will not only risk the wood stack tumbling down, it'll just be a disruptive mess that will no doubt aggravate all of the fishes, including that skittish pair of Betta coccina that are finally starting to come out after weeks of timid appearances.

Can it wait a bit longer? Does the plant grouping really need to be thinned out now?

The aquascape really doesn't look that bad, right? And that rare red Crypt; is it REALLY that cool? I Mean, it WAS pricy, but...

Sometimes, it's about doing stuff that's simply annoying. Maybe it's messy. It's always disruptive, to some extent...And occasionally, it's about decisions which affect the harmony of the tank.

And then, there are those other times...the so-called "911" moments. The ones that result from rolling the dice and making a decision that could have went either really good or really bad...and it went really bad this time. The need to act is pretty much a given...Adding that extra male Ram to the small group you had in play created a big blowup in the social order; this new guy is being chased all over the tank by the dominant fish.

All of the other fishes are sort of freaked out by the aggressiveness, hiding or acting weird; this calculation was wrong on this occasion, and the consequences threaten the life of the new fish, and the overall harmony of the tank. It's obvious that the new guy needs to come out- and fast. And of course, this the beautifully planted, intricately-scape tank that you've been sharing all over Instagram, and moving the wood and those rocks to get the one beleaguered Ram out is going to pretty much destroy the scape. Oh, and did I mention, he looks like all of the stress may have caused him to contract some sort of disease...Why is he scratching?

And this time, the "can it wait?" calculus is not really in play. Nature- and the fishes- have made the decision easy for you..Well, "easy" is relative, of course. More like-binary. The consequences of waiting- on this occasion- are pretty obvious. Leaving this fish in means he dies, and possibly spreads disease to the rest of the inhabitants. Those "micro-calculations" you occasionally make about "...the needs of the many being more important than the needs of the few or the one..." (to borrow a famous Star Trek phrase)  are of now out of the question.

Time to "rip off the Band Aid" and act.

It can't wait.

The most humbling, if not educational hobby moments often come from the simple set of decisions that we have to make- decisions that were set in motion by other decisions, perhaps weeks or months before. Yet decisions which have both short and long-term implications for your aquarium. 

And always, hopefully- you learn and grow as a result of both the experience and the decision.

As the old expression goes, “Good decisions come from experience, and experience comes from bad decisions.”

That pretty much sums it up, right? 

Besides, that chattering noise the pump is making really IS annoying, huh?

Stay decisive. Stay observant. Stay diligent. Stay grounded...

And Stay Wet.


Scott Fellman

Tannin Aquatics 



March 11, 2019


The philosophy...

I know that I seem to spend an inordinate amount of time dwelling on obscure and arcane topics in the aquarium hobby- I mean, someone has to, right? 

We try to do lots of interesting little projects here at Tannin which not only are fun, but help us work through the basic philosophies that we operate by. Stuff like trying out different ideas and either "crashing and burning" or succeeding wildly, right in front of you guys- no "safety net" required. It's foundational. We have to push ourselves to do things a bit differently than we have done before- in both theory and practice. It's what drives us as hobbyists, and Tannin as a company, to "move the needle", if ever so slightly, of the hobby's state of the art.

It seems like no tank that I've presented in the last year or so has generated so much "buzz" in our community as the one that I created for my Tucano Tetras. I mean, I felt it, too. Something about this tank- this idea- that is clicking. Not exactly sure what  exactly it is about this one, but I've received so many emails, DM's, and questions about it that it made me reflect even more about the simple philosophy which guides everything we do here. I'm thinking it's at least in part because it absolutely reflects our philosophy in a tangible way.

I think that it's important to look at the work that we do as hobbyists- specifically, the tanks we create- as little "microcosms" that are essentially our fishes' entire universe. That's not too much of a stretch, but it's a really important "cornerstone philosophy"- one that separates the "natural style" aquarium enthusiast from say, the pure aesthetic aquascaper, breeder, or casual fish keeper.

Even at the hobby's most "basic" levels, you as the aquarist create the physical environment for your fishes, and are more or less in control of every facet of its existence. You control the appearance, environmental parameters, population, input and export of nutrients- like, everything. And the health and lives of each and every organism which resides in the aquarium are completely in your hands.

Like, 100%.

Kind of an awesome responsibility, when you think about it that way, huh?

It is.


And, while our fishes go about their daily existence likely not comprehending all of that, and likely behaving in your aquarium in much the manner that their wild ancestors have for untold millions of years, what they DO know is that this is their world. The physical structures you've created, the water parameters, the competing population of fishes, availability of food resources, and the quality of the water are just a few of the things they contend with like they would if they were swimming about in the wild. 

I mean, that's our hope, anyways...right?

This is one of the reasons why I have had a near-obsession with attempting to recreate, to some extent, as many of the physical/environmental characteristics of their wild habitats as possible for the fishes under my care. All the while, realizing that, although they will be residing in a closed system with many physio-chemical characteristics similar to what they have evolved to live under, it's not a perfect replication, much though I might want it to be, and being of the opinion that replicating "some"of these characteristics is likely better than replicating "none" of them. I have no illusions about this- and there is a far cry between recreate the "look" and mimicking the function of the habitat.

An arrogant assumption on my part, I suppose. I mean, like every one of you, I'm fully responsible for the animals which I keep, and I take a certain degree of pride in that. I want the best for them.

That being said, I'm personally not in that mindset of having to be absolutely "hardcore" about being 100% accurate biotopically, in terms of making sure that every leaf, every twig, every botanical is from the specific habitat of the fishes which I keep. I do respect aquarists who do, however. But that's not me. Rather, I place the emphasis on providing a reasonably realistic representation of the habitat form which they come, with aquascaping materials, layout, and environmental parameters as close as possible to the parameters in the wild.


You can be a very responsible owner, pushing the state of the art of the hobby forward, without obsessing over making every micro-semion of conductivity, or every ppm of phosphate in your tank match that of your fishes' wild habitat. I'm pretty confident about that.

Your fishes likely don't know that, having been captive-bred for a few generations, or collected from their natural habitat and being subjected to varying environmental differences along the chain of custody from stream to store. The likely don't even care. They're likely just happy to be somewhere stable by the time they arrive in your home aquarium!

Our fishes being genetically "programmed" by evolution to live under certain environmental parameters for millennia can't likely be replaced by a few dozen generations of captive breeding. You know, just substitute a line or two of "code", and presto! However, being able to acclimate and thrive-even reproduce- in conditions significantly different from what they evolved under does indicate some good adaptability on the part of our fishes, doesn't it? 

And as an aquarist, we benefit from this, even though our hearts may tell us it would be a cool idea to try to be 100% faithful to nature in this regard, despite the difficulties involved. 

Of course, all the while being fully aware that, for example, achieving and managing a 4.3 pH similar to the floating leaf littler banks of the Aliança Stream (a tributary of Branco River in Brazil), for example, is beyond the level of detail that I want to go into! It would be very cool to do, but it's just not what I'd want to do at the moment.

I suppose my attitude towards those factors would "disqualify" me personally from being a very hardcore biotope aquarist- at least one who would try to compete in a contest! 

The Tucano Tetras I keep, of course, don't know this.

Nor do they seem to care.

None of the fishes I keep do.

Rather, they're preoccupied with finding their next meal, socialization, and other more mundane aspects of their daily existence. As long as they are physically comfortable and free from high levels of stress as a result of evading predators and exploiting very limited food resources, I don't think one could make an argument that they do care...

And just because you're content with your aquariums being "biotope-inspired" as opposed to 100% faithful to replicating the aesthetics or physical characteristics of the natural habitat you're into doesn't mean you don't care, aren't doing a good job, or aren't dedicated to your craft.

What every fish under your care does know is that they are living in a stable, stress-limited environment that they can easily adapt to and live out their lives in.

And that's worth considering the next time you set up an aquarium, isn't it?

I think so.

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

And Stay Wet.


Scott Fellman

Tannin Aquatics

March 09, 2019

1 comment

The stuff we're afraid of...And a plea for honesty, patience, and humility. A rant.

All of you who know me personally know that I'm about as geeky and traditionally-raised aquarist as they come. I was brought up in a world of fancy guppies, killifishes, and Neon Tetras. I had my first legit aquarium when I was about 5 years old...after having maintained goldfish bowls since I was around 3. Aquarium keeping was in my blood, just as it was in my father's before me.

I've been fortunate enough to have grown as a hobbyist, tried all sorts of different stuff; travelled the world studying aquariums, speaking, and starting and managing two successful companies in the aquatics space. It's been a good ride so far!

Yet, like many of you, for a long time, I harbored some fears about stuff in the hobby. Yeah, I was afraid for a long time to walk outside of the well-trodden path worn by our hobby forefathers. I tried all sorts of fishes and aquariums, but seldom, if ever, deviated from what would be seen as decidedly mainstream. To do so not only meant facing the scorn of the hobby community, it meant potentially failing or doing something that had no pre-conceived rules or guidelines...

And that can be scary.

About 15 years ago, I simply decided never to be scared again in the hobby. I started experimenting with all of those ideas and approaches that were in my head for so many years...And most important, I decided that I couldn't give two &*^*&%^^%$ about what anyone thought about the stuff I tried.

It's been really healthy. And very quiet in my head...

Although on some days, I want to yell...

Unfortunately for you guys, today is such a day. 

We have a lot of fears that we may not want to admit to, IMHO.

One of the things that drives me crazy is this innate fear of "detritus", "dirt", and "decomposition" that seems to have been beaten into the head of every hobbyist since time immemorial...A fear; a warning that tells the hobbyist that anything decomposing in the aquarium will degrade water quality, unleash horrific algal blooms, and kill your fishes...

The admonition for decades has been to siphon up every gram of detritus each time we change the water in our aquariums. The prevailing thought in the hobby is that this stuff is only bad news:

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


It's one of our most commonly used aquarium terms...and one which, well, quite frankly, sends shivers down the spine of many aquarium hobbyists. And judging from that definition, it sounds like something you absolutely want to avoid having in your system at all costs. I mean, "dead organisms" and "fecal material" is not everyone's idea of a good time, ya know?

Yet, when you really think about it, "detritus" is an important part of the aquatic ecosystem, providing "fuel" for microorganisms and fungi at the base of the food chain in tropical streams. In fact, in natural blackwater systems, the food inputs into the water are channeled by decomposers, like fungi, which act upon leaves and other organic materials in the water to break them down. 

Now, sure- the stuff  just doesn't look that nice to most of us, and that's partially why the recommendation for a good part of the century or so we've kept aquariums is to siphon it the hell out! And that's good advice from an aesthetic standpoint- and for that matter, from a husbandry standpoint, as well. Excessive amounts of accumulating waste materials can lead to increased phosphate, nitrate, and other problems, including blooms of nuisance algae. Emphasis on the word "excessive" here...(which begs the question, "What is "excessive" in this context, anyways?)

However, with the importance of detritus in creating food webs in wild leaf litter communities, which we are now replicating in aquariums, could there actually be some benefit to allowing a little of this stuff to accumulate? Or at least, not "freaking out" and removing every single microgram of detritus as soon as it appears?

I think so. Really.

Is this another one of those long-held "aquarium truisms" that, for 90% of what we do is absolutely the correct way to manage our tanks, but which, for a small percentage of aquarists with the means, curiosity and inclination to experiment, could actually prove detrimental in some way?

I think so.

Another thing that absolutely drives me crazy, and goes hand-in-hand with the fear of detritus and decomposition is a stunning lack of patience that I have seen in the hobby for years now.

We're afraid to wait. TO let things happen. To evolve. We want it done...NOW.

I am going to beat that impatience out of you if it's the last thing we do here.  And

I'm going to call us all out:

I absolutely, 100% blame this on the "hardcore aquascaping world" who feature these instant "masterpiece scapes" and make little to no mention whatsoever about the time required for an aquarium to cycle, to process nutrients. To go through not-so-attractive phases. For plants to establish and grow. To go through the phases where things aren't established. THE TIME. It takes weeks or months to get a tank truly "established", regardless of what approach we take, or what type of tank we're setting up. 

Don't be afraid. And yes, not everyone hides the process.

Only about 95% of us.

What we've done collectively by only illustrating the perfectly manicured "finished product "is give our brothers and sisters the impression that all you do is choose some rock, wood, and plants or whatever , do some high concept scape, and Bam! Instant masterpiece.  Yes, there are PLENTY of people who actually think that...WHY are we so f- ing scared to show an empty tank, one with the "not-so-finished" hardscape or plant arrangement? The period of time when the wood may not be covered in moss, or when the rock has a film of algae on it? One that has perhaps an algae bloom, a bunch of wood that needs to be rearranged, etc.

That's reality. That is what fellow hobbyists need to see. It's important for us to share the progress- the process- of establishing a beautiful tank- with all of its ugliness along the way. 

This does severe long-term damage to the "culture" of our hobby. It's sends a dumbed-down message that a perfect tank is the only acceptable kind.

I freaking HATE that.

Stop being so goddam afraid of showing stuff when it's not "perfect." You don't need anyone's approval. Period.

To all of appeal: PLEASE STOP doing this.

At least, without taking some time to describe and share the process and explain the passage of time required to really arrive at one of these great works. Share the pics of your tank evolving through its early, "honest"  phases. That's the magic...the amazing, inspiring, aspirational part EVERY bit as much as the finished contest entry pic.

Wanna help the hobby? Do that.

Patience. The passage of time. Allowing Nature to do her work...These are things that we as humans seem so afraid to let happen. We seem to feel that the time required to establish a truly healthy, beautiful tank naturally is somehow "wasted" or uninteresting.  As if it's devoid of value until the tank is "ready for Instagram" or whatever. We're afraid to share anything that's not perfect.

Nothing could be further from the truth. That's the whole game! The beauty of watching a tank evolve- at whatever speed it does- from a disorganized "mess" to a beautiful microcosm of life in all its forms- is a gift from the Universe. 

The types of aquariums we do in our little niche absolutely should be documented in all of their phases. The turbid water, the tint. The biofilms. The "patina" of growth on wood...All of these are beautiful things that change over time, and need to be shared so that the world understands exactly how these tanks come into being.

Successes , challenges, and indeed, our failures  should be we can all learn, and understand that Nature is as much a "process" as it is a "thing." And that there is beauty everywhere if we shift our minds to accept it.

Yes. Tannin will organize a contest one day soon. And yes, it will have lots of pretty inspiring tanks. But HELL YES- all entrants will be required to show the raw, unfinished beauty of the evolution of the display as part of the deal. The goal is to show that an aquarium, like Nature itself, is a dynamic, constantly evolving system. Things like algal films, biofilms, decomposing botanicals, pockets of sediment and detritus are every bit as compelling, beautiful, and awe-inspiring to look at as any ultra-manicured "finished" show tank. 

Nature unedited.

Patience. A lack of it will simply wreck your hobby experience.

FACT: If you add all of the contents of your "Enigma Pack" to an established aquarium that has been stable for some time, you will likely kill everything in your tank. Think about the logic here. You can't add a shitload of biological material to any established system and expect there to be no impact on the aquarium environment. The bacterial population as to adjust to the new influx of materials. 

And guess what? That takes time. And time is really boring to a lot of people. The very, very few emails I receive from people who wipe out their aquariums after adding botanicals are almost always caused by human error. Adding too much too fast. Not preparing materials. Not thinking.


Yeah, you may stare at an aquarium full of pods, leaf litter, mud, and detritus for a few weeks or more before it's safe to add fishes. Or, you may add your botanicals just a few at a time over the course of weeks.

Oh well. It takes time. Enjoy the slow process. Enjoy your aquarium at every phase. 

Along the way, you'll gain a tremendous appreciation for how Nature works. And a sense of patience, pride, humidly...And ultimately, the realization that an aquarium is never truly "finished." 

It's a journey. Frought with peril if we make it that way. Filled with wonder, beauty, and amazement if we accept it.

A journey that we can't be afraid to take. 

Until next time...

Stay bold. Stay observant. Stay methodical. Stay patient...

And Stay Wet.


Scott Fellman

Tannin Aquatics 



March 08, 2019


Microcosms, representations, functionality, and education...Positive mental shifts from the "botanical revolution..."

It's kind of neat to hear from many of you in our community discussing your aquariums in terms of "microcosms" of life. This is something that, while not exactly "new,' is gaining greater prominence. Making that mindset shift back towards that old aquarium hobby adage that an aquarium is essentially little closed ecosystem, subject to the influences of Nature on a small scale.

An acceptance of both the function and appearance of Nature is, surprisingly, a big leap for many hobbyists to make. This is profoundly different than the more popular point of view that a "natural" aquarium is a highly contrived, aesthetics-first elegantly aquascaped aquarium dominated by aquatic plants. A realization that there is more to the concept of a functional aquarium than just plants. Other natural materials are equally important.

And of course, the idea of aquariums inspired by, or representing Nature doesn't mean that every single plant, twig, rock, etc. found in a given habitat you're recreating must be included in order to complete your aquarium. That type of ultra-hardcore authenticity is the realm of the serious biotope aquarium enthusiasts- the guys who enter those contests where they model very specific biotope. You know, like the ones that they name: "Shallow stream off of the Tano River, 3 km north of Sunyani, Ghana." Stuff like that.

Nothing wrong with that, of course. However, I can't help but laugh at the criticisms levied by contest judges against biotope aquariums in these contests because they're using "the wrong grade of sand" or whatever, to properly represent that environment, when the substrate is clearly dominated by European Beech leaves or Alder Cones from North America, or whatever. It's just a bit...well, amusing to me. 

I'm personally more interested in the overall "look" and atmosphere (and "functionality") of the habitat from an aquarium perspective, and that's what we've built Tannin around. I realize that there are specialized habitats where the "authentic" materials, like rocks or substrates, can make a difference in the function (like African Rift Lakes, Peat Swamps, Soda Lakes, etc.), but for the bulk of our replications, I think that having materials which represent those found in the habitats we're interested is a more than adequate approach.

Key word here being "represent"- and perhaps more thoughtfully or faithfully than we've done in the past, with as much emphasis on function as on the aesthetics.

Many of the items we use in aquairums, for example, Catappa leaves, may not be found in the specific habitat we're trying to replicate, but they effectively represent the leaves found in the streams and rivers we're interested in modeling our aquariums after. (The irony is that the Indian Almond tree has been transplanted to tropical regions worldwide, for better or for worse-so it actually may end up being more "biotopically correct" than you might think in some areas!)

Replication versus Representation...

One of the things we enjoy most here at Tannin is offering materials that help you recreate your own representations of all sorts of aquatic habitats. We have worked hard to source materials which help you create some cool looks and some of the "functionality' of wild aquatic habitats.  I know that many of you have asked for leaves and pods and such from specific regions, and we hear you. We've been on that for a few years now; never as easy as it seems to be!  

We're working our global suppliers constantly to find "real deal" materials from various tropical regions of the world, consistent with sustainability, economic viability for our suppliers, and import regulations.  It's a slow process, fraught with challenges, but kind of fun! Some items are heavily regulated for export by their native countries, and getting them out is next to impossible (as it should be!). There may be ecological impacts from removing some of these materials from the natural environment, even though they are "fallen and dead"-and we must respect that.

Many times, we've had to get creative.

In the case of Estuary, for example, some the items we sourced were recommendations from aquatic biologists who specialize in brackish water ecology. They gave me some tips about what (more readily available) materials would serve as suitable representations of some of the things found in these habitats, because, once again, they are typically not available in any type of quantity or frequency.

Sometimes, however, unexpected circumstances led to us getting exactly what we wanted! In at least a couple of cases (stories to follow at a later time), we were told by government officials that we were actually doing them and the local environment a favor taking some of these items out of their territory, as they were invasive in nature and they didn't want them there! Talk about a "win-win" situation!

And when you think about it, even the most ardent biotope fanatics "push it" just a bit. I mean, how do you know 100% that the rock or wood that you're using is actually from that specific river proximate to Yasuni National Park in Peru? Can you even obtain it from there? Likely not. Do the judges of these contests really know that? Probably. Isn't there some leeway in judging this based on the understanding that some of this stuff simply isn't available (you can't collect from a national park, right?), and that "facsimile" materials have to be used?

I think so.

I think all of these people get it.

However, to the hardcore hobbyists who ply their trade in the world of 99.999% authenticity- you people amaze me. As someone who is dedicating his life and business  to helping offer materials for hobbyists to replicate the natural environment, you have my complete respect. If you get excited because you actually found a twig from, say, the Apoquitaua River in Brazil- much RESPECT! I get you.

I think the fact that we're seeing more and more hobbyists making efforts to learn about the natural habitats of our fishes on a "macro" level is amazing. A real game changer, IMHO. Understanding the surrounding environment of the aquatic habitats that  we want to replicate is hugely important, not only to our knowledge base as aquarists, but to understand the uniqueness of these habitats and the urgent need to protect and preserve them.

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

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

Creativity, energy, and ingenuity are all necessary "equipment" for the lover of biotope-style (notice I said "style?") aquariums. It's a fascinating, lifelong pursuit, and the rewards of educating others, learning for ourselves, and sharing what we know are amazingly satisfying.

And, if somewhere along the way, we end up breeding a few fishes, developing some new techniques, and "moving the needle" of aquarium keeping forward just a bit, it doesn't get any better than that! 

Until next time...

Stay excited. Stay enthusiastic. Stay fascinated. Stay inspired. Stay diligent...

And Stay Wet.


Scott Fellman

Tannin Aquatics




March 07, 2019


The land of the Tucanos: A case study of a good, but not perfect philosophy

One of the best things about writing your own blog every day is that you develop- well, for want of a better word- fans. And fans not only consume your content; they analyze it, discuss it, criticize it, and request more of it!

One of the many questions I received lately was about how my philosophy of creating a tank works. Now, at first, I had to laugh a bit...I was like, "Umm, you buy a tank, fill it with water, and..." Of course, that WASN'T the gist of the question. What the questioner really wanted to know was how I decide what to include and how to configure my aquariums; what guides these decisions.

It's a pretty good question!

The summarized answer? It's all about the habitat.

Now, I don't profess to be some sort of "guru" on the philosophy of aquarium design and such. However, I do have some definite opinions about what drives my designs.

First off, I am a keen observer and student of wild aquatic habitats and ecological niches in the tropical world. I have found that I am drawn to certain types of habitats; typically, those in which terrestrial materials, like soil, leaves, seed pods, and the like influence the ecological characteristics of the water, and the fishes which live there.

That being said, I will not only observe the aesthetics of the habitat which I want to replicate- I spend a ridiculous amount of time trying to replicate, as faithfully as possible, the function of the habitat as well. The whole tagline for Tannin, "Leaves. Wood. Water. Life" sums up beautifully my mindset: That the aquatic environment strongly influences the health and sustainability of the fishes I keep, and that it's as important to curate and utilize natural materials in such a way as to mimic the habitat as it is to select great specimens.

I have long believed that, despite the fact that many fishes, like Discus, Tetras, etc. are kept and bred successfully in hard, alkaline "tap water" conditions- and have been for generations in the hobby/industry- there is almost always something to be gained by "repatriating" our fishes to conditions that are similar to those which they have evolved to live in for eons.

I just don't believe that a few dozen generations of captive breeding under dramatically different environmental conditions (ie; hard and alkaline water) than their wild environments have eclipsed or erased the evolutionary adaptations to specific conditions. I mean, sure, just because fishes are adaptable to radically different environmental parameters than they evolved to thrive under doesn't meant that it's "better" for them.

I think we can and should do things a bit differently.

We have to draw a distinction between what's best for the fishes and what's easiest for us as hobbyists to create and maintain. And arguably, if we don't bother to study, understand, and appreciate the wild aquatic habitats from which our fishes hail, how can we understand their fragility and the dramatic impacts of humans on them? Your fishes may "come from a hatchery"... But that's not where fishes come from.  Make sense?

I think so.

So, to summarize- my philosophy is to study and understand the environments from which our fishes come, and to replicate them in function and form as best as possible. It doesn't always mean exactly- but it's definitely NOT forcing them to adapt to our "local tap water "conditions without any attempt to modify them.

I have a very current  "case study" of my own that sort of reflects the execution of my philosophy.

As many of you know, I've had a long obsession with the idea of root tangles and submerged accumulations of leaves, branches, and seed pods. I love the silty, sedimented substrates and the intricate interplay of terrestrial plant roots with the aquatic environment.

I was doing a geeky "deep dive" into this type of habitat in Amazonia, and stumbled upon this gem from a scientific paper by J. Gery and U. Romer in 1997:

"The brook, 80-200cm wide, 50-100 cm deep near the end of the dry season (the level was still dropping at the rate of 20cm a day), runs rather swiftly in a dense forest, with Ficus trees and Leopoldina the water as dominant plants. Dead wood. mostly prickly trunks of palms, are lying in the water, usually covered with Ficus leaves, which also cover the bottom with a layer 50-100cm thick. No submerse plants. Only the branches and roots of emerge plants provide shelter for aquatic organisms.

The following data were gathered by the Junior author Feb 21, 1994 at 11:00AM: Clear with blackwater influence, extremely acid. Current 0.5-1 mv/sec. Temp.: Air 29C, water 24C at more than 50cm depth... The fish fauna seems quite poor in species. Only 6 species were collected I the brook, including Tucanoichthys tucano: Two cichlids, Nannacara adoketa, and Crenicichla sp., one catfish, a doradid Amblydoras sp.; and an as yet unidentified Rivulus, abundant; the only other characoid, probably syncopic, was Poecilocharax weitzmani."

Yeah, it turned out to be the ichthyological description of the little "Tucano Tetra", and was a treasure trove of data on both the fish and its habitat. I was taken by the decidedly "aquarium reproducible" characteristics of the habitat, both in terms of its physical size and its structure. 

Boom! I was hooked.

I needed to replicate this habitat! And how could I not love this little fish? I even had a little aquarium that I had been dying to work with for a while. 

It must have been "ordained" by the universe, right?

Now, I admit, I wasn't interested in, or able to safely lower the pH down to 4.3 ( which was one of the readings taken at the locale), and hold it there, but I could get the "low sixes" nailed easily! Sure, one could  logically call me a sort of hypocrite, because I'm immediately conceding that I won't do 4.3, and I suppose that could be warranted...

However, there is a far cry between creating 6.2pH for my tank, which is easy to obtain and maintain for me, and "force-fitting" fishes to adapt to our 8.4pH Los Angeles tap water! 

So, even the "create the proper conditions for the fish instead of forcing them to adapt to what's easiest for us" philosophy can be nuanced! And it should! I don't want to mess with strong acids at this time. It's doable...a number of hobbyists have successfully.  However, for the purposes of my experiment, I decided to abstain for now, lol.

And without flogging a dead horse, as the horrible expression goes, I think I nailed many of the physical attributes of the habitat of this fish. By utilizing natural materials, such as roots, which are representative of those found in the fish's habitat, as well as the use of Ficus and other small leaves as the "litter" in the tank, I think I'm well on the way to creating a cool biotope-inspired display for these little guys!

That's one example of this philosophy in action. Again, it's NOT perfect. It's certainly something that can- and should- be improved upon. The pH thing, for example. But the physical environment; the biological nuances...the long-term function of this type of aquarium microcosm...I think we are well on our way to building a lot of "best practice" stuff here. 

I'm still not satisfied yet...

However, I think it's a good start.

I think it also requires the usual caveats- a "mindset shift" that embraces the fact that the natural habitats we love don't always meet our "acculturated" aesthetic expectations. We need to understand that Nature does her own thing, regardless of whether we "approve" of it or not! 

Keep striving.

Stay bold. Stay studious. Stay curious. Stay diligent. Stay open-minded. Stay methodical...

And Stay Wet.


Scott Fellman

Tannin Aquatics 




March 06, 2019


Doubling down on YOU: My case study.

Ever have one of those personal breakthroughs in the hobby? Perhaps it's just an epiphany, or maybe a development that gets you where you wanted to be after a long period of trying to figure it out?

Yeah,I had one of those recently; I'll share it with you later.

However, that "big picture" of self-awareness within the hobby is something I frequently discuss with fellow hobbyists. 

One of the best things I've learned in the aquarium hobby is to be realistic about what I can and can't do well. The hobby challenges you and humbles you that way. And that's perfectly okay. Because, like with any endeavor, you can always improve at the craft. You can get good by simply trying, failing, learning, and persevering. It's pretty cool.

You CAN learn to breed fishes. Rear fry. Culture live foods. Plumb your reef tank. Test water. Build a dream company...


Anyone can do those things well with time and dedication.

Although some things are a lot more difficult to "improve" at, IMHO. Some stuff requires that you have some skills that (I Know behaviorists out there will argue) you have to be born with...LIke the art of aquascaping, for example. I mean, sure, we ALL have some creative ability and art is really subjective. However, I the aquarium world, there are  many hobbyists who seem to have that "X factor" nailed.

They are fabulous aquascapers. They could take the same branches and rocks that I have and create something universally appealing 99 times out of 100. That's amazing to me. You may not always like the style of their execution, but you can't argue with their skills.

I must admit, as I have many times- I'm not a very good "technical" aquascaper. 

I couldn't properly arrange an "Iwagumi" rockscape to save my life. I'm about as bad at tying mosses to wood as they come. "Dutch Style"? C'mon! I can't even do "Benign Neglect Style" well! "Golden Ratio?" Heard of it.  Diorama Style? Awed by the skills required; yet would rather keep hamsters than be good at that "style..." (okay, I AM opinionated, at the very least...)

Yeah, so anyways...

I know what my limits and skills are (the limits are many and the skills are few)...and I'm perfectly okay with that. Rather than try to mimic the 1,000 splashy 'scapes I see on my Instagram feed each morning, I do what moves me. 

And I do it well. 

And so do you.

Rather than try to mimic what someone else does so well, I've chosen to direct my aquascaping energies to what I love. I've doubled down on ME. 

What I am is an "aquatic habitat interpreter" of sorts.

Yup. That's me.

I can look at an image of an aquatic habitat and try to recreate aspects of it in an aquarium. Not a stylized version, mind you. I can't do that well. Rather, an unfiltered interpretation of it. A version for the aquarium. 

Now, part of the "interpretation" of natural habitats for an aquarium involves the "mental shifts" that I've told you about many times here. An acceptance that Nature is a perfectly imperfect place. A dirty, seemingly random, earthy place that, when one opens his/her mind to it, is filled with more beauty than 10,000 top Instagram feeds! 

Patience, perseverance, and the willingness to try a few iterations to achieve what you're working on are super important.

And it helps to have some of the materials and tools to do the job! That's where we come in, and this personal story plays out.

As you all know by now, I have a strange obsession with the Igapo flooded forests of the Amazon. The tantalizing random mix of soils, leaves, roots, and botanical materials in water speaks to me. I have spent years gawking at these habitats, learning about them, and trying to figure out ways to represent them both aesthetically and functionally in the aquarium.

It's a habitat that has driven many of my aesthetic choices and aquarium environment experiments over the years. I've sourced materials, scoured scientific papers, and played with many dozens of aquariums over the decades trying to achieve that "functional aesthetic" balance, and to recreate, on some levels, the habitats I love so much.

I've played with various iterations of this habitat in various aquariums for quite a while. I feel like I really have a handle on some of the dynamics of this habitat and how to recreate a functional representation of it.

For some time, we have offered a material called "Senggani Root" as part of our "Twigs and Branches" selection.  It's a rather unique material, with a thick little "trunk" and a delicate "filagree" of roots. It has a lot of potential for use in 'scapes, with its intricate matrix of space for fishes to forage amongst, microorganisms to reproduce in, and mosses to attach to. 

It's awesome stuff.

When my supplier in Borneo approached me about carrying this stuff, there was no hesitation at all. It was love at first sight. However, it's also one of those materials that you can think about how to use, yet when it comes to executing, it's a bit trickier than you might think to get it right. The old adage about "listening" to the wood and it'll tell you how to use it rings true with this stuff.

I played with it for a while. We utilized it in several concept scapes, to great effect. 

Yet, I knew that there was a different way I could use it. 

For the longest time, I've had this vision of a root tangle on the floor of a flooded forest, reaching down among larger root structures towards an earthy, leaf-strewn substrate. I'd seen pics of this sort of thing in Nature and the temptation to do a representation of it haunted me. I have this little tank in my office that I've been dying to execute this in...

I started with a layout featuring a matrix of thicker nano-sized "Spider Wood" pieces as the "superstructure" for the scape. Of course, it needed some detail. It needed the more intricate, delicate look that only actual roots could provide.

What could I use? I needed something delicate, yet sturdy enough to last.

Aha! Finally, an opportunity for the Senggani root to play a part!

I figured that there was a way to work these more delicate, light-colored roots into the structure to create that sort of tangle.

With a little positioning and shuffling, three pieces of this branch were starting to give me the effect I was looking for all these years! A breakthrough of sorts! And the solution was right there in my facility all of these months...

You know when you just "feel it?" Yeah, that was me. I knew that I was finally moving in the direction I needed to be headed.

After a couple of days submerged, the addition of more soil, leaves, and bits of botanicals, and my "igapo root tangle habitat" began to emerge!

Those details- more leaves and botanicals, bits of Pygmy Date Palm fronds, crushed aquatic soil (I used Ultum Nature Systems "Control Soil"), and the passage of time, have yielded the look and hopefully, the function, which I've sought to achieve for so long. Once more of a "patina" emerges on the roots, and the biocover and "sediment" settle in on the Spider Wood and the slowly-decomposing matrix of botanicals on the substrate- I think I'll have what I came for!

The next steps will be done by Nature. She's in control from here. Decomposition, fungal growth, and the reproduction of microbial life in the aquarium will not only dictate how the microcosm functions, but how it looks as the tank matures.

My simple story here is nothing more than one of the many examples of why it's so important to "speak to your truth" and do what YOU love. If you try to do what "the crowd" thinks is cool or "it", you'll miss out on YOU. You'll never get to experience the joy of creating and sharing what you love.

Always double down on YOU.

Stay unique. Stay creative. Stay undaunted. Stay observant. Stay diligent...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


March 05, 2019


Wisdom about wood...Patience, persistence...and aesthetics.

If you're like me, you are virtually fearless about dumping all sorts of natural materials into your aquariums...It's kind of what you do. Sure, there is a learning curve in regards to how much you can "get away with", but the potential for breakthrough benefits for your fishes is too great to overlook for many of us.

Someone asked me if we are going to start offering (insert stupidly-named wood type here). And of course, I had to think about this for  just a bit. 

It seems to me that, on any given day, such-and-such a wood type is the "IT" variety, and everyone wants it. Some guy does a tank with this scraggly shit emerging from the water, posts a few sexy pics on his Insta feed, and the next thing you know...trend.

As someone who offers natural aquascaping materials for use in specialized aquariums, I long ago realized that I needed to stop chasing every hot type of wood that shows up on the market. I have found some types which have proven to be great to use in our natural-style aquariums. I am generally clueless on "what's hot" in the aquascaping wood world.

We'll continue to offer types of wood that we enjoy using in our own 'scapes. Some will just happen to be ones that are popular and relatively common- or even "trendy" at the moment. Some will be types which fell out of favor with the mainstream 'scaping world. Some will be obscure, niche-specific stuff.

The majority, however, will simply be stuff that works.

That answers that., I hope?

Of course, that means I'm really the last guy who should be discussing what wood to use in your aquascapes. Rather, it will be a discussion on what happens at that magical moment when we place wood in water...


First off, let's think about where our wood comes from.. It doesn't take much to figure out that the most important thing is that the wood must be…well, DRY! It can’t be “live”, or have any greenwood or sap present, as these may have toxic affects on fishes when submerged. Sap can be toxic, even when dry, so if you see a piece of wood that’s oozing some sap- it might be a good idea to take a pass. For the sake of this discussion, let's just assume that you're working with wood that's been properly collected and is suitable for aquarium use.

When you first submerge wood, a lot of the dirt from the atmosphere and surrounding environment comes off, along with tannins, lignin, and all sorts of other stuff from the exterior surfaces and all of those nooks and crannies that we love so much. And the stuff typically floats, much to our chagrin, right?

And of course, there are 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 driftwood. I mean- what's the big deal?

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

The reality, as you probably have surmised, is that driftwood will continue to leach tannins 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 the humic substances that are known to have health benefits for fishes.

Some wood types, like Mopani, 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 mangrove wood, seem to be really "dirty", and release a lot of materials over long periods of time.

And it's a unique aesthetic, too, as we rant on and on about here!

What I'm more concerned about are the impurities- the trapped dirt and such contained within the wood. As you probably know, that's also why I'm a staunch advocate of the overly conservative boil and soak approach to the preparation of botanicals as well. A lot of material gets bound up in the dermal layer of the tree where the wood comes from. Atmospheric dust, pollutants, bird droppings, insects, etc.  None of this is stuff you want in your tank, right?

The bulk of the dry mass of the xylem (the "network" within the tree which transports water and soluble mineral nutrients from the roots throughout the plant, and comprises what we know as "wood.") is cellulose, a polysaccharide, and most of the remainder is lignin,  which is a sort of complex polymer. 

Why the botany lesson?

Well, because when you have some idea of what you're putting into your tank, you'll better understand why it behaves the way it does when submerged! In a given piece of driftwood, there is going to be some material bound up in these structures, and it will be released (gradually or otherwise) into the water that surrounds it, with a big "burst" happening on initial submersion. This is why, during the first couple of weeks after you submerge wood, that the water often becomes dark and even cloudy.

There is a lot of "stuff" in there!

It's far better, in my opinion, to take the time to start the "curing" process in a separate container apart from the display aquarium. This is not rocket science, nor some wisdom only the enlightened aquarists attain. We all know this, right?

It's common sense, and a practice we all need to simply view as necessary with terrestrial materials like wood and botanicals. You may love the tannins as much as I do, but I'm confident that your tank could do without those polyscaccharides and other impurities from the outer layers of the wood. The potential affects on water quality are significant!

It's pretty plain to see that at least part of the reason we see a burst of new algae growth and biofilm in wood recently added to an aquarium is that there is so much stuff bound up in it. Algal and fungal sports can literally "bloom" during the initial period after submersion, and this alone is great reason to take the long, slow approach to wood prep.

In fact, geek that I am, over the years I've long made it personal practice to submerge wood which I intend to use in my tank a couple of months before I set up my tank. This will enable a good percentage of the bound-up contaminants and unwanted organic materials to be released before the wood ever graces your aquascape! And it goes the wood a chance to saturate and sink, too!


What about boiling?

Well, sure, boiling can hasten the process somewhat. But here's the deal-most of us don't have a kettle, pot, or other large enough container in which to boil a big old piece of wood, so the long-term "pre-soak" is the optimal approach. 

And let's face it, even with preparation, when you combine water, light, and organics, you're likely to get some fungus, biofilms, and even algae- for some period of time. Some fungal growth and biofilms are to be expected in the earliest days of "submersion. These tenacious life forms will exploit available nutrients and conditions that are appropriate for their survival. Just like with our botanicals, it's a normal occurrence.

We may not like the way it looks in our tanks. I totally get that.

Now, I remember deliberately NOT pre-soaking the wood in my office tank (I love torturing myself, apparently) just to see how nasty this could be. (oh, the things I do for you in the interest of sharing knowledge!)

The result? It literally took about 4-5 months before the wood stopped producing biofilm and attracting hair algae in really large quantities.

That was freaking punishing. Well, I found it kind of cool, but pretty much everyone who saw the tank during this period thought otherwise...😫

Eventually, the familiar "patina" of harder algae came to prominence.  And minor biofilm on the softer parts of the wood will still pop up on occasion...Just like it does in nature. It's normal. It's not dangerous.

It's okay.

And of course, along the way, you can incorporate some "biological helpers", like algal and detritivorous-consuming fishes and even snails (yikes!) to help out. Of course, many, many fishes will "peck" at biofilms and other growth on wood and botanicals as a part of their daily "foraging" activities.

And of course, good old-fashioned aquarium husbandry and stepped-up maintenance practices never hurt, either!


And having a good, soft-bristled toothbrush on hand can help with the "day-to-day" upkeep, if needed. Likely, the stuff will continue to return until the "fuel" which caused their appearance and growth in the first place diminishes.

Obviously, happy endings typically will happen with aquarium wood, given the passage of time and perhaps a bit of assistance from the fish geek, but it's important to understand WHY the algae and biofilms appear on wood, and how to react when they happen.

Like so many things in a truly "natural" aquarium, they may not meet our aesthetic standards, but if we have a greater understanding of just what they are, why they appear, and how to address them (or not..), we can make that "mental shift" that you hear me ranting about so often on these pages.

Embracing a new paradigm of what a "natural" aquarium really is.

One that doesn't cause us to rush off, headless, screaming into the night (or onto Facebook) when some algae or biofilm appears! Goes with the territory. Embracing Nature in all of her glory is what we're all about. 

Expectations. Education. Patience.

All "core skills" which we as aquarists need to acquire to bolster our success, understanding and perseverance as we push the boundaries of aquarium keeping.

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

And Stay Wet.


Scott Fellman

Tannin Aquatics 

March 04, 2019


Fascinating features; seldom replicated...until now.

It's interesting to me to contemplate ways to replicate unique ecological niches that we haven't played with all that much in the hobby. I mean, there is a lot of ground-breaking aquascaping work being done from the artistic perspective, and some amazing biotope aquariums replicating various locales and such, but some of the more odd or unusual microhabitats are seldom replicated, and I think it's sort of a shame, given the global talent pool, availability of materials, and interest.

I for one, would love to see more of these amazingly talented "artistic" 'scapers riffing on some of these interesting ecological niches.

As you probably know by now, we're big fans of habitats like leaf litter beds and flooded forest floors. Not just for the unique aesthetics that they present, but for the potential "functionality" these habitats bring to the aquarium. I think that these habitats, which host a huge variety of fishes, can be "foundational" for unlocking some new secrets of aquatic husbandry. 

And by doing a bit of research on natural leaf litter habitats, you can glean some interesting tidbits of information that can be applied to aquarium design. And of course, you get perspective on the threats and challenges facing these habitats. Here's an example of one aspect of these habitats I learned about from a scientific study- the relationship between water depth and leaf litter depth- and how it can be applied to our aquarium designs:

In an area where the water depth was a maximum of 6ft/2 meters, the leaf litter depth was only about  8 inches/20cm. In a very shallow side tributary, the litter depth was about 4 inches/10cm, with the water level above it only about 12 inches/30cm!  

That's like "aquarium depth", right? Yeah.

Now, these are just a few of many different areas affected by seasonal inundation, and there are numerous areas that are several meters deep during peak months. However, on the average, many of the little Igarape that I found information on were at best a meter or two deep, with correspondingly deep leaf litter beds.

Obviously, most of us aren't going to use an aquarium that is much more than a meter in depth, but we can always utilize the ratio of water to leaf litter/substrate and play with whatever dimensions excite us. Nonetheless, I'm a big fan of shallow/wide, because if you do build up a nice botanical/leaf litter layer, you don't have a huge column of water above, and can really focus on some of the bottom-dwelling fishes which make these areas home.


I think an ideal tank dimension for a leaf-litter biotope-style aquarium would be something like 48"x 18"x 16" /121.92cm x 45.72cm x 40.64cm (about 60 gallons/227.12 L)...shallow and wide, indeed! With these kinds of dimensions, you could create a leaf litter bed over a thin covering of fine, white sand, with a depth of about (4 inches/10cm) and a water column of about 12 inches/30cm above it. This proportion is a very good simulation of this type of habitat.


With a relatively low profile tank, you're not likely to feature "vertically-oriented" fishes, such as Angelfishes, in this tank! Rather, you'd focus on fishes like characins, including the leaf-litter dwelling "Darter Characins" like Aphyocharax, Elachocarax, Crenuchus, and Poecilocharax. For interest, you could introduce some biotipically appropriate Hoplias and Otocinculus catfishes, too. For the "upper" water columns, you could play with specimens of various Hatchetfishes and Pyrrhulina, killies like Rivulus, and cichlids, such as specimens of  Apistogramma, Aequidens, and Crencichla. 


Obviously, this is just a guide based on some studies of these areas, and you can create your own species mixes and even specialize in one or two featured species found in these habitats (that would be VERY cool!). The important thing, in my opinion, would be that you are attempting to create a few different aspects of these unique habitats. Filtration could be provided by either a canister filter or an outside power filter, with flow directed towards the surface.

Water temperature, based on studies, would be perfect if you could keep it at about 26 degrees C/78 degrees F.  Now, the pH of many of these habitats that were surveyed averaged around 3.5-4.2- extremely acidic water with no real ionic content, that, as we've discussed previously, is something that is challenging to achieve, and equally as interesting to maintain (notice I said "interesting", because it's not impossible...just challenging). My little shallow leaf litter bed tank was able to maintain a pH of about 6.2-6.3. A far cry from the aforementioned 4.2, but not bad, from an aquarium standpoint!

Thusly, a modest-sized aquarium operated at low pH would be a great "testbed" for various types of research into the maintenance of these types of biotopes. Likely, you could "scale up" once you've mastered achieving your desired pH in a small tank.

Just one of many fascinating features of Nature, seldom faithfully replicated...until now. Let's see more of these unique ideas and replications! 

Stay creative. Stay curious. Stay observant. Stay bold. Stay diligent...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


March 03, 2019


Geology, big ideas...and dirt. Another Sunday ramble through the mud...Literally.

I'm thinking it may be time to really play with dirt.

I mean, flat-out, full-on, dirt-from-the-garden-bed dirt. Obviously, nothing with pesticides or whatever...but, like dirt.


Now, I know that the idea of "dirted" tanks is not at all new, particularly to the planted tank world. There is a whole fascinating subculture of planted people doing amazing things with "dirted" tanks. I enjoy reading about their almost rebellious simplistic approach. I love these guys! Part of me loves them because, at least to this outsider, they appear to be pissing off "the establishment" and their fancy gadgetry and snobbish approach. They're doing this complicated thing in such a simple matter that it draws criticism from the "experts", which is just badass. Now, they're utilizing garden soil and such, which is geared towards, well- growing stuff. 

What I'm talking about is utilizing it in a tank where plants are not the primary focus. Like, using it as part of an aesthetic and functional substrate. Where the impact of the material on the environment of the aquarium as a whole is more important than its ability to grow...plants. 

I'm talking about a fish-centric microcosm.

This is where I part ways with these bold rebels...

Yes, I'm thinking about dirt...the stuff in your garden that get's kind of muddy when it gets wet. Would using this stuff in your substrate, either "solo" or as a "mix", be a cool way of capturing the "look and feel" of some of our blackwater habitats? Now, I realize it's  A LOT more complicated than just throwing some dirt into the water, and that the chemical compositions of many of the soils which originate in the tropical regions we attempt to replicate in our aquariums are often vastly different geologically from our North American/European soils. Yet, I find it sort of intriguing to utilize clean dirt (shit, is THAT an oxymoron?) in a botanical-style, blackwater aquarium. 

This is probably one of the more reckless, least scientific ideas I've wanted to play with in a while...There is absolutely no basis for using "just any old dirt" in a blackwater, botanical-style aquarium- other than the fact that "dirt" is found in many of the streams and rivers of the world.

There must be some benefits, right?

Sure, super alkaline soils or soils with a lot of salt or other mineral content will possibly wreak havoc on our attempts to create soft, acidic waters- but there must be some types of soils with some attributes that will perhaps release some beneficial trace elements and minerals into the water? Again, I AM NOT SUGGESTING THAT ANYONE DO THIS without a lot of consideration and forethought...but...

I'm merely sharing with you something I might play with at some point.

When I was working on an aquatic display for a museum in museum Connecticut several years back, we were growing riparian plants from the beaches of Long Island Sound, and I remember literally digging up clumps of these plants, along with the surrounding soil and mud, and utilizing them in an aquarium with local marine was an incredible display...Super simple, but cool- and the experience never quite left my head...I thought, "Why not do this with a tropical freshwater tank?" 

Or, perhaps with brackish?

Now, with Estuary, our foray into brackish water, the idea of utilizing/recreating the muds and silts and leaves for substrate and as a huge part of the closed ecosystem is the basis of our mangrove biotopes, and I can't help but let my mind return back to that "dirt thing" and the potentially interesting benefits (like the potential to impart trace elements, organics, etc. to the water) that could come from it. Mixing muds and soils with dried mangrove leaves and some botanicals would be a very interesting long-term game!

My vindication for my strange dirt/mud obsession came when I had a brief chat with Mike Tuccinardi, who was thinking through a brackish display, and we are touched briefly on how to simulate/utilize/recreate mud in the aquarium in a way that is, well, "muddy", and sort of concluded that more thought is required on this!

Mud and dirt can be used in a variety of ways, besides just for planted aquariums- once we figure out how best to utilize them! You know, mixing them with sands and other materials. 

There are some cool commercial products out there, and I have played with them before and will in the future...I just wonder what the ins and outs of using naturally collected stuff could be. 

I'm rambling. Not really fully developing the idea..Just sort of throwing out thoughts. It's an idea...sort of one of those "bring up to your fish geek friends and let them run with it" types...

Yet, soils and rocks and materials like these play a huge role in many of  the natural habitats we're curious about replicating in our tanks.

It's a scientific fact that one of the most important influences on blackwater rivers is the geology- the soil and sedimentation of the surrounding areas. It starts with the soils. Blackwater rivers, like the Rio Negro, for example, originate in areas which are characterized by the presence of white sands known as "podzols." (note that, biotope-oriented aquascapers!)

Podzols are soils with whitish-grey color, bleached by organic acids. They typically occur in humid areas like the Rio Negro and in the northern upper Amazon Basin. And the Rio Negro and other blackwater rivers, which drain the pre-Cambrian "Guiana and Brazilian shields" of geology, can in part attribute the dark color of their waters to high concentrations of dissolved humic and fulvic acids!

Although they are the most infertile soils in Amazonia, much of the nutrients are extracted from the abundant plant growth that takes place in the very top soil layers, as virtually no plant roots are observed in the mineral soil itself.

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

Hmm..nutrient concentrations, ionic composition and minerals and...this stuff is interesting.

Perhaps...another reason (besides the previously cited limitation of light penetration) why aquatic plants are rather scare in these waters? It would appear from studies I've stumbled upon that that the bulk of the nutrients found in these blackwaters are likely dissolved into the aquatic environment by decomposing botanical materials, such as leaves, branches, etc.

Why does that sound familiar?

Besides the color, of course, one of the defining characteristics of blackwater rivers is pH values in the range of 4-5, and low electrical conductivity. Dissolved minerals, such as  Ca, Mg, K, and Na are negligible. And with these low amounts of dissolved minerals come unique challenges for the animals who reside in these systems.

How do fishes survive and thrive in these rather extreme habitats?

It's long been known that fishes are well adapted to their natural habitats, particularly the more extreme ones. And this was borne out in a recent study of the Cardinal Tetra. Lab results suggest that humic substances protect cardinal tetras in the soft, acidic water in which they resides by preventing excessive sodium loss and stimulating calcium uptake to ensure proper homeostasis.

This is pretty extraordinary, as the humic substances found in blackwater actually enable the fishes to survive in this highly acidic water which is devoid of much mineral content typically needed for fishes to survive!

Oh, and this juicy finding in a study on humic substances in ornamental fish aquaculture really perked up my senses a bit:  "Humic substances are not real alternatives to strong traditional therapeutics. However, they show different advantages in repairing secondary, stress induced damages in fish."

Something in those leaves and botanicals, right?

And this goes far beyond just the cool aesthetics they impart, too! Like, what we are doing with leaves, twigs, substrate materials, seed pods, etc. has a physiological impact on the fishes we keep. 

What a powerful incentive to study and enjoy both the aesthetics and environmental enhancement capabilities of the botanical materials we tend to be so obsessed with around here!

A lot to unpack. A lot to think about. Much to still learn and figure out. We as a community and global movement are off to a pretty good start, though! It's exciting to contemplate what's next!

Stay excited. Stay curious. Stay unwavering. Stay bold. Stay diligent...

And Stay Wet!


Scott Fellman

Tannin Aquatics 

March 02, 2019


Flooded forests, sunken grasses...emerging ideas?

I'll be the first to tell you that I'm not an aquatic plant expert. In fact, I know very little about them! However, I'd be inclined 

The reality is that many of the (South American) habitats which we play with simply don't have much in the way of true aquatic plants in them. For example, the igapo flooded forests and small streams usually just don't have much more than epiphytic algae and submerged terrestrial plants in them.  

However, you can grow plants in your "version", of course. I think it's more of a matter of trying various plants which tend to come from lower ph, blackwater habitats, and applying these ideas to their care. My list is ridiculously superficial, of course- so you hardcore plant people will have to take the flag and run with this!

(The Red Howler Monkey knows a thing or two about Amazonian plants and trees! Image by Gordon E Robertson, used under CC BY-SA 3.0)

Now, my other "challenge' to plant lovers in general: Let's figure out which terrestrial plants can tolerate/grow/thrive under submerged or partially submerged (blackwater) conditions. Perhaps a more "realistic" (not in the hardcore "biotope aquarium contest" context, of course) avenue to explore in this regard?

I've got one tree for you to research...the dominant terrestrial plant in this habitat is Eugenia inundata... Don't think I'm not well underway in my (somewhat futile) efforts to see if we can secure fallen leaves of THIS plant! You'll also find Iriartea setigera, Socratea exorrhiza, Mauritiella aculeata palms in these areas..

(Mauritiella aculeata - Image by pixel too used under CC BY 2.0)

Like so many things from the Amazon, it's not easy (read that, damn near impossible) to secure botanical material from this region, so the proverbial "Don't hold your breath waiting for this" comes to mind! Oh, and the submerged grasses we see and drool over in those underwater pics from Mike Tucc and Ivan Mikolji of these habitats?

They're typically Paspalum repens and Oryza perennis.

Paspalum is found in North America, too...possibly a species you could obtain?

(Paspalum. Image by Keisyoto. Used under GFDL)

Perhaps you could, right? And it's that kind of stuff that keeps us working away.

Simple idea for today...

Stay curious. Stay excited. Stay engaged. Stay diligent...

And Stay Wet.


Scott Fellman

Tannin Aquatics