August 24, 2019


For the love of rock...

Like many of you, I enjoy playing around with aquascapes. I'm interested in creating all sorts of aesthetics which tie in with the natural habitats we are into. And often, that involves using rocks. Well, not that often, actually, now that I think of it...However, on those occasions when I DO use rocks, it can be fun... 

I mean, usually.

But, like, one or two rocks isn't exactly "aquascpaing with rocks", right?

And that's typically the extent of my work with rock these days...The sad truth is, I'm not particularly good at it! Now, you'd think that, being a reefer, arranging rocks would be second nature, right? 

Well, perhaps.

Nah. I admit, I suck at it. 

Even when I was a reefer, where rocks are the whole game in aquascaping...I sucked at it, for the most part. The only saving grace for people like me is that the corals will grow to over over whatever "rockwork" you create! So, if you grow nice corals, you still look like an aquascaping genius! 

I mean, sure, I can create a little pile here and there.

I can replicate a reef, maybe create little areas of rock reminiscent of those that you'd see in a stream...But those "artistic", Iwagumi-style rock arrangements or carefully thought-out hardscape featuring rock...

No chance. None at all. Like, zero.

That's why I lean on my friends to do the work when I want serious use of rock in something, lol.

Leaves? I'm fearless...I'd dare say, I am a master at them, lol. Seed pods? Easy- I'm in my element! Driftwood and twigs and such? Totally. I mean, I'm no George Farmer, Jurjis Jutajevs, Cory Hopkins, or Johnny Ciotti- but I can come up with some stuff that works...

But, rocks?

I love them.

I love those Iwagumi scapes. I love bold scapes which seem to effortlessly integrate rocks into the wood and other elements.. 

I mean, I admire them greatly.  I'm sort of in awe of the skill of those who create them. I just have zero interest in doing them myself. I'm not much of a "technical 'scaper."

And, if you think about it- pretty much every aquarium which I've done and shared with you on these pages pretty much doesn't feature a single rock in it! Ever notice that?

So it IS kind of funny to walk into my facility and look at all of the rock we offer for sale, and think to myself, "It's totally beautiful...But I have no idea how to use this stuff!"

Yeah, that's some brutal honesty! 

Now that Tannin has evolved from just a "blackwater specialist" to more of a "natural aquascaping specialist", providing inspiration and materials for a wide variety of habitat replications, it's neat to take a fresh look at materials like rocks. And very therapeutic for me, actually!

It's fun to think of rocks as vital components of aquariums modeled after Nature. There are so many possible combinations and possibilities to create amazing stuff with these simple elements!

And, it's also important for us to explain why we typically don't see rocks in some of our fave blackwater habitats, like the igapo- the seasonally-flooded forests of Brazil. There are some reasons that make real sense!

The "whitewater" rivers of South America rush quickly down from the mountains of Peru and Bolivia, too rapidly for clay and silt to be stripped from them. The rocks from these mountainous areas offer minerals and nutrients such as nitrogen, attached to the silt and clay, and minerals like illite, montmorillomite (hey, we know that one from shrimp geeks!), and chlorite, to nourish the lower-lying areas.

In these areas, numerous microbes and plants consume some of the nitrogen, and while eaten by other organisms, convey what's left to the even lower-lying forest habitats.

The Amazonian blackwater rivers are largely depleted in nutrients, having passed through the lowland forest soils as groundwater, from which weathering has already occurred. "Hydro-geomorphic processes" ( i.e.; a fancy way of referring to part of the stuff that makes rocks!) are far less intense than they are in the upland, mountainous regions of The Andes, with their abundance of minerals, nutrients, slits, and sediments.

In other words, the result is that most low-lying Amazonian forest soils are really low in nutrients. The soils are nutrient-poor, acidic "podzols..." It's been suggested that most of the available nutrients are taken up by the root mats of the dense plant growth in these forested areas. And even the rainwater provides little in the way of nutrient for the plants which grow there.

However, what little nutrient there is typically returns to the soils by means of leaf drop from the trees which grow there. And of course, when the water returns to the forest floors, what little nutrient remains is released into the waters, too. And it's quickly utilized by the resident microorganisms.

Serious nutrient cycling, right?

I'm no expert-or even a novice- on geology or geochemistry, or anything in that subject area, for that matter....However, based on my research into this stuff, it goes without saying that these are hardly conditions under which rocks as we know them could form.

Now, you might find the random rock in the igapo that was washed down from the Andes or some other high-country locale in these forests, but it did not evolve there. This also helps to explain why the blackwater habitats are generally low in inorganic nutrients and minerals, right? 

Yet, you might find areas of rocks which have accumulated, into which blackwater streams and rivers might overflow into. These would be cool potential niches for us to replicate in aquariums, huh?

However, if you're really, really hardcore into replicating an igapo in your next aquarium, you'd probably want to exclude rocks...

I've pretty much obsessed over this particular habitat; I can't help but wonder if there is subconscious bias I have against rocks- and THAT is why I never scape with them?

Nah! Couldn't be.

Well, maybe?

On the other hand, with all of the delightful possibilities that nature offers for us to replicate unique natural habitats in our aquariums, utilizing rocks in your 'scape is just a cool thing to do, huh?

A little research, a little practice, and a bit of sleuthing about the natural aquatic habitats  of the world can yield remarkable amounts of inspiring information! And we know a place where you can find some really cool rocks, when the muse hits...

Leaves. Wood. Water..Life. And ROCKS. All working together.

I love rock. I LOVE rock. Must convince myself... 😂

Hmm...I'm going to go down and look at our rock bins again. I know I suck, but I have this idea that I've been meaning to try...It might work this time...

Stay creative. Stay inspired. Stay persistent. Stay thoughtful...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

August 23, 2019


Shifting with the seasons...Pt. 2


I think we shall be lovers
Through all the seasons yet to come......
Until the end of time

.- From the poem, "For All Seasons" by Linda Ori

After yesterday's piece, we received a fair amount of interesting feedback and discussion from our community. A lot of you were curious about how we could more realistically and impactfully execute "seasons" in our botanical-style aquariums. It's amazing to see you having discourse about this concept which has not previously been discussed much in the hobby, to my knowledge. 

As we gradually ease towards Autumn here in the Northern Hemisphere, it's easy to contemplate the subtle- and sometimes not-so-subtle- things that occur when the seasons change. And of course, I can't help but wonder how this affects our fishes, and how they might benefit from understanding these changes and applying our own version of them in our aquariums?

We all know a little about what happens during seasonal changes in Nature: The weather patterns shift. These are profound impacts on the wild habitats of our fishes. They have important effects on the way our fishes live out their lives. I think we kind of beat the shit out of this concept yesterday. However, I think we can still examine this on a more practical level...

I mean, it's obvious how the seasonal shift affects our personal hobby efforts, right?

With cooler weather prevailing in many parts of the world, and outdoor activities starting to become a bit less attractive in some areas, many hobbyists once again turn their focus on to their aquariums. Many are focused more on perhaps starting-or finishing-projects which previously were delayed in favor more appealing summer activities.

Aquarium clubs their have big annual shows. Attendance at their meetings goes up. As aquarium industry businesses, we notice an uptick in sales activities and customer interest. It is notable, predictable...logical consumer behavior.

Yes- it's "Aquarium Season" here in the Northern Hemisphere! Time to play with some new ideas- or to perfect some that we've already started working on. This is a very exciting time! 

Now, all seasonal celebrations aside, what kinds of impacts do seasonal changes have on aquariums and the fishes which inhabit them, that we can capitalize on as hobbyists?

Well, for one thing, lighting differs. With high tech LED systems now readily available, and less expensive all the time, it's never been easier to manipulate the color temperature, angle, intensity, and duration of light in our aquariums. Each of these aspects has potential implication for the husbandry of our fishes. This is a vastly unexplored area in the freshwater aquarium world; ripe for exploration and potential breakthroughs!

Since many of the areas from which our fishes hail are near the Equator, there is very little temperature variation between the seasons. However, the rainy season in these areas does occur, and impacts the aquatic habitats significantly.

The wet season, as we discussed yesterday, is extremely important for our fishes which hail from these regions.

In the Amazon, for example, the wettest part of the wet season occurs between December and May. During the wet season, the Amazon rainforest receives as much as 6 to 12 feet of rain (1.98- 3.6m), which can cause rivers like the Amazon to rise as much as 40 feet (12m), flooding the surrounding forest areas! The fishes adapt by moving into these areas that were previously barren and dry, foraging among the now-submerged trees, grasses, and plants.

As a lover of this flooded forest habitat, I find it irresistible to study!

I believe that the process of creating a "dry" (terrestrial) 'scape, and then gradually flooding it with water, as we've shared with you a lot recently, is one of the key "unlocks" to learning more about these seasonal changes on the environment and our fishes.

Even starting with a shallow-water level and gradually increasing the depth and making some compositional changes to the physical environment, by adding more botanical materials, is a good simulation of these dynamics.

Look for our launch of the "Urban Igapo" products in the coming weeks, to make it easier than ever to experiment with this process, Tannin Aquatics style! (Okay, shameless business plug out of the way...)

Everything seems to adapt in the rain forest, including even the trees. Trees have adapted to this seasonal flooding by developing roots that grow above the ground. These roots are known as "buttress roots." They would be an interesting feature to replicate in the aquarium, right? We would simply start our tanks by choosing pieces of driftwood which resemble these features; or, we can utilize several pieces to recreate the look- and function of them!

What "function" can an "artificial" recreation of this physical feature perform? Well, for one thing, it can become a place to sequester/accumulate leaves and botanicals- much like happens in the wild habitats. My much-maligned (by ME, lol) Asian-themed blackwater aquarium at home embraces this idea and attempts to replicate the feature.

Yeah, I personally am so over this tank, lol-more on this soon- but it has served its purpose validating my thoughts on this idea!


So, it always seems to come down to leaves in the waterways, doesn't it?

And of course, the leaves come from trees, and fall into the water. Yet, it's not quite that simple, actually. There are processes and cycles involved with leaf drop that we can replicate in the aquarium to some extent.

For example, recent studies have shown that rainforest trees and plants actually "flush" (grow new leaves) shortly before the arrival of the dry season. It's postulated that there is something in their "genetic programming" that allows them to prepare for the onset of the relatively "light-rich" dry season, to get them ready for  enhanced photosynthetic activity. Even the onset of the dry season could be replicated in an interesting manner in our aquariums...

You'd "pulse" the addition of leaves during this period, which would, of course, mimic this natural process effectively!

And with regard to that "wet season", how do we sort of mimic the environmental effects of the seasonal inundation in aquariums that are already "wet?" In other words, in an existing "filled" aquarium?

Well, short of running them half-full most of the year, and then increasing the water level to full during the "rainy season" (ohh...that's a cool idea!), perhaps we could mimic the "dilution" in the water which occurs when massive amounts of rain fall. In other words, lots and lots of consecutive water changes! Like, maybe a few times week in greater percentages.

And we could supplement this with greater flow, from the filter outputs or the addition of powerbeads, etc.

"Fellman, you're insane! The benefits that you'd get from all this extra work aren't worth it."

Do you know that for sure?  (the "benefits" part, of course. You already figure the "insanity" thing is a definite possibility, lol). There is a reason why fishes react to seasonal changes the way they do.

I think it's a worthwhile experiment.  🤓

Of course, other things you could do to mimic this seasonal inundation are to add more and more leaves and botanicals during this time, mimicking the affects of continuous leaf drop and the accumulation of botanical materials caused by currents.

And perhaps even "refreshing" the substrate with additional material (like soils, know, that planted aquarium stuff) to sort of simulate the release of new organics and other compounds caused when previously dry forest floors are inundated with water. I find this idea sort of intriguing!

Oh, and you can add a lot more food.

Like, feed a lot of live food like Daphnia, copepods, worms, fruit flies, etc. Stuff that would likely be more readily available to fishes in an inundated environment. Perhaps even changing the diet seasonally to reflect this abundance would be interesting. Now, I'm not suggesting to starve your fishes the rest of the year, but I am curious if there would be any significant effects that we'd notice in captivity by varying the diet and quantity fed to our fishes based on seasonal availability of different food sources...

Creating aquariums which replicate more specific conditions within the context of seasonal changes, including the availability of food sources within the aquarium, is a fascinating process with broad-reaching implications.

I mean, fishes have evolved over the eons to feed in this manner...Could it be a key to better breeding, perhaps activating some "locked-up" genetic programming in even our captive-bred cichlids, characins, and catfishes?  I know that I talk about this a lot- because I think there is something there. Could the application of the impacts caused by these seasonal cycles be an "unlock" that puts those difficult-to-spawn fishes "in the mood?"

Who knows? However, doesn't it make sense to investigate?

I think so!

There are many, many different seasonal change "cues" and occurrences which we as hobbyists can study and experiment with to see what- if any- impact they might have on the fishes we keep.

The adaptations, behavior changes, and spawning activities which occur in our fishes are certainly be tied into these seasonal changes, and perhaps the key to more predictable/successful spawning of challenging or previously "un-spawnable" fishes could be replicating them, to some extent, in our aquariums.

Something to think about.

Something to play with as the days grow colder, the nights grow longer, and the opportunity to spend more time in our fish rooms beckons.

What secrets will YOU unlock?

What geeky experiments will you try? What lessons will we learn? What fishes will we spawn? How much money will we spend on fish stuff in the process? 😆

Wait. Don't answer that...

Please do consider this process of studying and replicating- to the extent that you can- the wonderful and fascinating seasonal cycles of Nature, and their impact on the fishes we are so obsessed with.

As much as you'd like me to, I'm not going to stop talking about this idea, lol. Besides, someone has to do it, right? Might as well be our community!

So get to it!

Stay crazy. Stay creative. Stay motivated. Stay innovative. Stay adventurous. Stay experimental. Stay inspired...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

August 22, 2019


Slipping through the seasons...

As you likely have figured out by now, we have a certain obsession here with replicating the form and function of Nature, to the greatest extent possible. And of course, the "function" part is often more of a challenge than the "form", so any processes found in Nature that we can replicate to some extent not previously executed in an aquarium is an evolution of sorts in our process, and a true "win" for the hobby.

Perhaps one of the more obvious, yet less tackled aspects of Nature that we can work on is...change. 


If there is one constant in nature, it's change.

And it's kind of ironic to me that one of the things we typically strive to avoid in fish keeping is change...well, rapid environmental change, anyways. Yet, we are typically sort of modeling our aquariums after a natural habitats, many of which do undergo significant periodic or seasonal changes during the course of a year, don't they?  Yet, although we are replicating some cool natural habitats as never before,  we don't usually vary environmental conditions throughout the year in our aquariums...

In fact, they're almost sort of "static" in terms of intentional seasonal changes, right?

Why is this?

I suppose it's another case of, "We do it this way because it's how we've done it for a century..."

Perhaps its time to loosen the chains of "conventional aquarium practice" and look towards some largely unexplored waters, right? Could there be something to be gained by modeling our aquariums after natural habitats during different times of the year? Some benefits for our fishes and the other organisms we want to nurture in our closed aquatic systems?

I think so!

Seasonal change is hugely impactful in tropical regions.

Its influence at every level is significant. Even the larger lakes undergo seasonal changes. For example, Lake Tanganyika, the second deepest lake in the world, undergoes surface water temperature changes throughout the year in its upper layers. Surely these have impact on the distribution, spawning, and feeding habits of the resident fishes, right?

In Amazonia, floodplain lakes associated with the river also undergo seasonal changes, which affect water quality. At high water phase, the large amount of nutrient input from the terrestrial environment causes the increase of primary productivity, and can lead to the lakes becoming very "eutrophic."

This also has an impact on the fishes which live there.

And of course, we all know about the annual killifishes of Africa and South America, which have adapted over eons to the varying seasonal conditions of rainfall and desiccation. They inhabit slowly evaporating pools, puddles, and wetlands, that dry out and fill once again during the rainy season-whenever that may be- and are highly variable, yet very dynamic environments, which give both life and death to the killies and other aquatic life forms which reside in them.

As hobbyists, I'd hazard a guess that we (unconsciously) tend to model our aquariums after one season in the wild habitats (if we even consider seasons at all), not really taking into account the significant changes that occur in these environments at various times of the year. If you look at it from a "literal" perspective, not taking into account the hobbyists who work with annual killies, for most of us, it's sort of "always the wet season" in our aquariums, right? 

Now, there is certainly nothing wrong with this approach.

After all, we're into keeping fishes, not creating recreations of of dry rainforest floors or empty mud holes! Well, maybe not just yet...And we should!

I just think that it would be kind of cool to model our aquariums after typical environments as they look and function at different times of the year. We've already touched on the flooded Igapo forests of Brazil, in which the forest floor becomes seasonally inundated by overflowing streams and rivers. It's an amazingly dynamic habitat that I'm glad we're starting to see more interest in.

Yet, I wondered for years how interesting it would be to take it even further, and create an aquarium around the seasonal changes in such a habitat. You know, with more shallow water levels, a greater ratio of botanicals/substrate to water, and different temperatures, lighting, etc.?

That was the basis of my "urban igapo" idea- starting out with a dry, "terrestrial" habitat and gradually flooding it to simulate the seasonal inundations which these habitats go through annually. I've done this several times, nuancing various aspects like soil composition, planting, and fish stocking along the way. It's become one of my fave projects, and I hope to see many of you playing with the idea more!

To that end, I've worked on varying soil "recipes" for both the igapo and varzea habitats, which operate similarly, yet have distinctly different physical characteristics. These become quite obvious when you begin playing with more functional environmental replications of them, too!

And of course, it's not just about these Amazonian habitats...there are numerous other habitats around the world that are suitable for such simulations.

What about a vernal pool in Africa that houses annual killifish?

Could lowering the water level significantly at various times of the year perhaps trigger specific behaviors related to the onset of the dry season? We already have a good handle on the spawning of annual fishes like Nothobranchius, and how CO2 and such affects egg viability, development,  and hatching times ( a concept known as "diapause"),  but I wonder if we could gain even more insight into the fishes themselves by gradually decreasing water levels to simulate this seasonal change?

Or perhaps even changing food sources to simulate the varying resources which are available during different seasons?

There are many fishes which could benefit from such replications.

If you recall, not too long ago, we talked about the Zebra Danio, and how it adapts to changing conditions in its native habitats. Typically, these fishes are found in Northern India, and this area is subjected to seasonal rainfall between the months of June and September due to the summer Monsoon, and the water levels and characteristics vary considerably at different times of the year.

They are often found in inundated rice paddies and marginal pools, with silty, kind of turbid water with very little movement. During the dry times of the year, they spend their time in calm, shaded areas of streams, with rocky substrates. How interesting it would be to give them "monsoonal" conditions, versus the conditions more typical of the dry season that we tend to provide them in aquariums!

I find examining these seasonal changes in the natural habitats and how they affect our fishes irresistible! There is something very alluring about perhaps gaining some small insights into how the environmental changes that occur throughout the year affect our fishes. I mean, there's more to it than simply raising and lowering water levels or temperature, but those a re good places to start, right?

What kinds of secrets could you unlock about your fishes by manipulating factors such as turbidity, water movement, substrate/botanical additions or subtractions, varying light intensity/duration, temperature (we've done this to some extent), pH, and even food supply? There is a lot of great scholarly data out there on almost any tropical environment you can think of, and with the concern over climate change, there is a lot of scientific information  analyzing seasonal variations in all sorts of aquatic habitats worldwide. 

It's out there for the bold, motivated hobbyist to apply to our aquarium work.

The passing of seasons, and varying environmental conditions they create are fascinating opportunities for us as hobbyists to examine and learn about how our fishes interact with their environments, and how we might be able to create even more successful outcomes for a wider variety of fishes.  Perhaps we could get some "movement" with some which have typically eluded or proven difficult to spawn to date using more "traditional" approaches.

I've been working with brackish habitats for a while now, and, although I've played around quite a bit with the water and substrate composition, I have yet to fully examine the idea of tidal influences- more frequent changes to the habitats...something that has not been worked with very much in home aquariums in the past. I think that there might be much to gain from replicating such fluctuations in the aquarium.

Mangroves are fascinating trees, and have proven to be adaptable, resilient, and quite easy to grow in captive systems. The impact of tidal changes, lighting, and substrate composition are all dynamics that we can and should study more in the context of our aquairums. These amazing trees are know to foster and support a very rich, dynamic ecosystem of both flora and fauna in Nature, which creates a significant food chain.

We can certainly make a greater effort to recreate this food chain-and its benefit- in our aquariums! 

What secrets could we unlock by playing with some of these ideas? There is so much more than just a cool look, believe me! Their extensive prop root systems and adaptations to the substrates they grow in alone could provide many years of breakthrough aquarium work- and fun- for those who choose to study it a bit more!

Amazing stuff that we can unlock simply by looking at things just a bit differently...

Now, sure, we already play around with some environmental conditions in order to induce spawning in our fishes, which is well-documented, so why not play around with (or at least, examine) various types of seasonal conditions for fishes to see what other impacts we can influence (i.e.; greater growth rate, coloration, appetite, etc.)? 

With all of the amazing curiosity, talent, and creativity in our growing global community of adventurous aquarists, there is a ton of room for amazing work and even some breakthroughs!

I hope that I've piqued the interest of at least a few of you into taking a different sort of look at the way we plan, develop, and manage our aquariums. Not that taking such an approach will guarantee groundbreaking results, sure to change the way we keep our fishes (it might!)- but it might just stimulate more ideas, more discussions, and facilitate the "connecting-of-the-dots" process of weaving together what we already know with what we haven't yet tried.

Simply influencing other hobbyists to look beyond just the aesthetics, and to consider how the natural ecosystems that we tend to replicate these aspects of actually function- and that these functions can be replicated with greater detail if we apply the same zeal to this stuff that we do to the "look!"

And, understanding these natural processes and replicating more and more of them in our aquariums can expose more and more people- even non hobbyists- to the wonder and fragility of these fascinating aquatic ecosystems, fostering a greater demand to protect them.

It's an amazing time to be an aquarist, isn't it?

I mean, we have the fishes, the technology, the materials, and the means to research arcane topics once considered solely the domain of scholars. We can actually execute on many of these things. We can try playing with concepts that we've likely never given much thought to previously. And we can rapidly communicate and share our ideas, successes, challenges, failures, and overall progress with fellow hobbyists all over the planet.

Nature is calling. 

This is how quantum shifts occur in the hobby. It's how significant evolutions in understanding and executing take place.

Yeah, those "passing fancies" might just create some entirely new paradigms for our hobby. Let's hope! 

We just need to jump in and get our hands wet!

Stay studious. Stay excited. Stay resourceful. Stay creative. Stay adventurous.

And Stay Wet.


Scott Fellman

Tannin Aquatics 

August 21, 2019


The real "One Percenters..."

The other day, I gushed to you about my fave "Holy Grail"-type fish, Crenuchus spilurus, and it seems to have struck a chord in some of you- always a great thing when you're a writer, BTW!

I was chatting online this AM with a friend in Europe (gotta love the era we live in, right?) about some upcoming aquarium projects that we're both doing, and we were discussing our dream fish selections for said projects- often lamenting the lack of availability or difficulty in obtaining various species. 

"I'd do a whole tank around that one...just can't find the damn fish anywhere..."

You've had those conversations, too. I know that you have!

This is both the bane of our existence and part of what makes the hobby so compelling and alluring, right?

As a lifelong hobbyist, I've spent a lot of time reading about, researching, observing, and collecting tropical fishes- just like most of you.


It's a big part of the hobby for many of us!

And, in all of those years of researching, I couldn't help but wonder about some of "those" fishes- you know, the ones that are found in scientific studies and papers about wild fish populations- fishes that seem to be ridiculously abundant in their natural habitats- swarming in and out of view in all of those underwater Amazon videos-yet almost never even showing up as a blip on the radar for the hobby!

What gives? Why do we rarely see them in the hobby?

The mind boggles...

Or, is there a logical, straightforward explanation that we don't always think about?

Now, there are plenty of reasons why some seemingly abundant fishes never show up in the trade, the primary one being that the collectors are simply not aware of any commercial value for them, and are far better off, from an economic standpoint, when they bring in 5,000 Cardinal Tetras instead of the abundant, but commercially "uninteresting" Hemmigramus elegans, for example.

A basically grey, nearly monochromatic characin has little in the way of value to the exporters, who need to satisfy the demands of wholesalers, who in turn, cater to stores...who cater to hobbyists worldwide. Now, one only needs to contemplate how different things would be if suddenly there was a huge demand for this fish from the hobby world. Like, what if it became the "it" fish for some reason? Maybe it was the easiest characin on earth to breed, or if it was determined that they contained a specific protein in their tissues that is effective at treating cancer or something; we'd no doubt see 'em coming in by the ton!

Duh. Easy. Obvious.

So it's really about demand.

And that makes sense. We love our hobby, but collecting and importing fishes is...well, a business. And business largely runs on seemingly almost unfairly "dry", yet prudent, fiscal decisions.

Now, when you think about it, a fish being relatively drab and unremarkable in appearance has at least one benefit- it takes external pressures off of the wild populations of many species! No one is typically grabbing the grey characins or unmarked cichlids, right? So they can reproduce at will and maintain an abundance, while their more colorful brethren are picked off by sharp-eyed, profit-motivated  fisherfolk by the thousand.

It's not really that difficult a concept to wrap our collective heads around, is it?

Yet, of course, as a hobbyist, I find myself wanting some of these less "interesting", yet relatively "common in nature" fishes to work with!

I know from my years in the marine side of the aquatic livestock industry that some of the more rare, less in-demand fishes will come in with more common, in-demand species as "incidental by-catch" on occasion, and the sharp-eyed hobbyist/collector can score a somewhat rare, albeit nondescript Tang, for example that just shows up in a shipment of 400 more commercially-viable Acanthurus leucosternonor whatever.

(Acanthurus chirugus Image by JT Williamns, used under CC BY 2.5)


These are always cause for celebration among serious marine fish enthusiasts, and many cool forum post has been dedicated to a (on the surface, at least) relatively unexciting brown Tang that an eagle-eyed, highly experienced hobbyist nabbed at the wholesaler or LFS, picked out of a large group of the more popular species it arrived with.

These little "discoveries" fuel a lot of people's passion for the hobby!

And it's the same in the freshwater market, of course. Sometimes a few of these (hobby) oddities will trickle through in a group of more widely known, more commercially viable species. And occasionally, they find themselves in the hands of some really sharp retailers who understand the (hobby) scarcity of the fish and their value to a hobbyist. This happens a lot with dwarf cichlids, like Apistogramma, and with catfishes, like Corydoras.

And that's what's fun, to me. You never know what might make it through! My local fish stores (and yours too, no doubt) has always had one of those "Any fish in this tank $1.00!" displays...and you just never know what true rarity you might find in there, cast aside from a tank full of more "viable" fishes...

And then there are fishes which don't make it in to the hobby to any degree because, well- they're not that appealing to a large number of hobbyists...yet. Perhaps they come from a specialized habitat, and need the same situation in an aquarium to show off their best color and vitality.

An example?

It's no secret that I've been obsessing for sometime about the small, relatively nondescript characin, Elachocharax pulcher. Part of one of my fave families, Crenuchidae, these are little, darter-like fishes that are common and abundant in the extensive litter banks of Amazonia in South America, yet virtually unknown to the hobby. A real shame, because they are fascinating fishes that we could do some cool stuff with in our tanks! 

They obviously would work really well in the leaf-litter beds that we're somewhat fond of replicating in our own aquariums, and would no doubt be popular within our tiny community of enthusiasts! They're cool enough that even hobbyists who have never heard of or seen them could be enticed to keep some if they were actually available!

Of course, I have no illusion that us- "the 1% of the 5%" of tropical fish enthusiasts who make up the segment of natural-style aquarium keeping, biotope-oriented characin lovers who keep leaf litter aquariums would even show up as an economically viable segment worth catering to by collectors!

However, what if a few of these cool fish got through...and what IF some capable hobbyists were able to breed them in viable numbers? Not only would success with obscure species like this release us from our reliance on chance collection/importation of them, it could possibly even permanently satisfy a demand- regardless of how tiny- for this cool little fish in the hobby!

And, most important, it could conceivably prevent any sort of need to continue to remove them from the wild. It's that "what if?" that keeps a lot of us dreaming! And of course, if enough people are exposed to such a fish, it just might open some eyes up to the pressures on the wild habitats which need our attention and care. A real "win" for Nature.

A very selfish, and I suppose, kind of a fantasy-like, almost blissfully ignorant point of view, I suppose, but fun to think about, right? Yet, entire specialties in the hobby, such as killifish keeping- are built upon this idea of obtaining and breeding relatively obscure species )and variants from different geographic localities) of fishes. 

(Yes we DO obsess...Chromaphyosemion sp.- Image by Mike PA Calnun)

And of course, it's not limited to just killifishes. There's Bettas, Apistos, L-number Loricarids, etc.

I can imagine if I polled a random group of you, there would be many fishes (from different families of course) just like my little friend, Elachocharax, which would be treasured by a tiny group, and diligently maintained, spawned, and preserved for future generations to enjoy. 

So, yeah- As part of our "fish geek due diligence", we need to keep an eye out on wholesale stock lists, and intently scrutinize vendors' and dealers' tanks, hoping, waiting, and watching. They may not be with us in the hobby right now- for any number of reasons, but these "out-of-sight", yet truly "aspirational fishes" are what keep a lot of us going... 

US, the real "one percenters..."

These fishes hold us spellbound, captivated, and diligent.

They're always on our minds.

What's your dream fish, and when will it show up?

Do you look for "substitutes"- or hold out for the "real deal?" How badly do you want it?

Keep searching.

Stay focused. Stay alert. Stay diligent. Stay persistent. Really- stay freaking relentless.

And Stay Wet.


Scott Fellman

Tannin Aquatics

August 20, 2019


Fish hooks man: An homage to "The God of Running Waters..."

There are numerous approaches to utilizing botanicals in our aquariums, ranging from the purely aesthetic idea of "tossing in a few leaves and seed pods", to a full-blown biotope-inspired aquarium, painstakingly thought-out to recreate the function and form of a specific habitat.

Of course, we've talked a lot about creating aquariums to replicate specific's kind of what we do here, right? Super rewarding. Yet, it's even more fascinating and rewarding to design an aquarium around a specific fish sometimes.

Especially when it's one that you have coveted for so long, right?

I'll share with you one of my personal "Holy Grail" I've no doubt discussed many times before here yet one that keeps me obsessed. Being a fish geek, I know that this is something you can relate to well:

We've all had that ONE fish which just sort of occupies a place in our hearts and minds- a fish that-for whatever reason- bites you and never lets go, right? I think that every serious aquarist has at least one such a fish..

Here's mine...

Of course, it's also about the habitat which this fish lives in that's kept me under its spell for so long...

As a lover of leaf-litter in our natural, botanical-style aquariums, I am fascinated not only by this unique ecological niche, but by the organisms which inhabit it. I've went on and on and spoken at length about many of the microorganisms, fungi, insects, and crustaceans which add to the diversity of this environment. And of course, we've looked at some of the fishes which live there, too! Perhaps not enough, actually...

One of my all-time favorite fishes- and my absolute favorite characin is none other than the amazing "Sailfin Tetra", Crenuchus spilurus!  This is a truly awesome fish- not only is it attractive and morphologically cool-looking, it has a great demeanor and behaviors which separate it from almost every other characin out there! 

It's almost "cichlid-like" in behavior: Intelligent, interactive, and endearing. It has social behaviors which will entertain and fascinate those who are fortunate enough to keep it.

Now, I admit, it's definitely NOT the most colorful characin on the planet. But there is more than this fish than meets the eye.

It all starts with its most intriguing name...

The Latin root of the genus Crenuchus means "Guardian of The Spring"- a really cool, even romantic-sounding name which evokes imagery-and questions! Does it mean the "protector" of a body of water, or some honorary homage to everyone's favorite season? Not sure, but you must agree that the name is pretty cool! In greek, it's krenoychos -"The God of running waters."

Yeah. That's the shit. I mean, do Latin names get any cooler than that?

The Crenuchidae (South American Darters) is a really interesting family of fishes, and includes 93 species in 12 genera throughout the Amazon region. Most crenuchids are- well, how do we put it delicately- "chromatically unexciting" ( ie; grey-black-brown) fishes, which tend to lie in wait near the substrate (typically leaf litter or aggregations of branches), feeding on insects and micro invertebrates. And the genus Crenuchus consists of just one species, our pal Crenuchus spilurus, a fish which shares habits and a body shape that are more commonly associated with Cyprinids and cichlids!

That's just weird.

Now, the relatively subdued coloration serves a purpose, of course. These fishes live among leaf litter, root tangles, and botanical tinted water...which demand (if you don't want to be food for bigger fishes and birds) some ability to camouflage yourself effectively. 

The Sailfin is an exception to the "drab" thing, and it's remarkably attractive for a very "simple" benthic-living fish. Sure, on the surface, it's not the most exciting fish out there, especially when it's a juvenile...but it's a fish that you need to be patient with; a fish to search for, collect, hold onto, and enjoy as it matures and grows. As the fish matures, in true "ugly duckling"🐥  style, it literally "blossoms" into a far more attractive fish.

The males have an extended dorsal and anal fin, and are larger and more colorful than females. Yes, colorful is relative here, but when you see a group- you'll notice the sexual dimorphism right away, even among juveniles.

Individuals spend a lot of their time sheltered under dead leaves, branches, roots, and aquatic plants. They tend to "hover", and don't dart about like your typical Tetra would. In fact, their behavior reminds me of the Dartfishes of the marine aquarium world...They sort of sit and flick their fins, often moving in slow, deliberate motions. Communication? Perhaps.

The Sailfin feeds during the daylight hours, and spends much of its day sheltering under branches, leaves, and root tangles, and is a mid-water feeder, consuming particulate organic matter, such as aquatic invertebrates, insects, bits of flowers, and fruits- the cool food items from outside of the aquatic environment that form what ecologists call allochthonous input- materials from outside of the aquatic habitat, which are abundant in the terrestrial habitats surrounding the aquatic ones which we love to model our aquariums after.

And of course, we can easily model our aquariums after these compelling habitats...

Yeah, we've written about that topic a lot...Recreating the habitats of leaves and other botanical materials which the fish frequent in Nature.  Liek, we talk endlessly about this shit, I know, but...

Hey, do those guys who sell leaves on eBay and such make the effort to discuss this stuff with you?  Oh, yeah... they don't...just sell stuff and don't bother to write (ouch, a DIG! )...yeah...No hate there, lol.

Oh, back now from my rather ugly digression...

And, further distinguishing the Sailfin from other characins is the males' parental care (yeah, you read that correctly!) of it's small (for a characin, that is) clutches of eggs (usually only like a max of 100) and larval stages of the fish- characteristic more commonly associated with cichlids than characins! 

Are you interested yet?

Wait, don't answer that! I'll keep going...

I first fell for this fish as a kid, when I saw a cool pic of it in my dad's well-worn copy of William T. Innes' classic book, Exotic Aquarium Fishes. The book that pretty much assured me from toddler days that I'd be a fish geek. I obsessed over the book before I could even read...

I was hooked from the start with Crenuchus, especially when reading about the romantic etymology of the name!  And it just seemed so "mysterious" and unattainable, even in the 1930's...well, especially back in the 1930's, but it seemed downright exotic! To this day, it's one you just don't see too much of in the hobby. And then, tying it together with my love of those leaf-litter-strewn habitats, it was a combo which I couldn't resist!

I never got this fish out of my system, and it took me like 30-plus years of being a fish geek to find this fish in real life. And, you know that I jumped at the chance..It was so worth the wait! The Sailfin is one of the most engaging and unique fishes I've ever had the pleasure of keeping!

Oh, and they are known to "vocalize', producing an audible "clicking" sort of sound that you can hear outside the aquarium...A very interesting phenomenon! Another interesting tidbit of knowledge about this fish" They possess an organ on the top of their head, which according to Gery, is "comprised of rod-shaped cells, encircled by a net of capillary vessels." What's it's purpose? No one is sure.

More mystery. More romance. 


Although they are a bit solitary in nature, I've found that they've do really well in groups, sometimes forming loose aggregations within the confines of the aquarium, hovering over the leaf/botanical bed, waiting for food. And they have a sort of "social order" that only they seem to understand, but it's very evident. A fascinating set of activities which makes them even more interesting-and endearing!

Sailfins might be a bit shy initially upon introduction to the aquarium, as these fishes are cautious, rather "sedentary" characins, and don't swim quite as actively as other characins. Like, no "Cardinal Tetra-style" shoaling behavior here. Getting them to feed regularly in the aquarium- while not difficult- may be a bit of a process, as they are cautious fish, and tend to not stray too far from the botanical cover. 

Think of all of the unique ways we could replicate parts of the habitats which they inhabit. 

If you have other, more active Tetras and other fishes in the aquarium, they'll be a bit more tentative at first. However, these are decent-sized fishes that will eventually overcome their initial shyness, and move confidently- if not slowly-throughout the aquarium. Though they tend to never stray too far from the protection of roots, wood, or leaves.

My kind of fish!

Once you keep this fish, I'm confident that you'll just sort of "get" it! If you just look at the fish, most of the time, it's really easy to simply dismiss it as "grey and boring..."

It's not.

IMHO, they're one of the most perfect fishes for the botanical-style, blackwater aquarium, especially, if you dedicate a system to their lifestyle and needs. And of course, it will fit right in to a well-thought-out natural, botanical-style community aquarium of smaller fishes, like the less "hyper" Tetras, Apistogramma, and catfishes.  

Again, these fish are so cool when housed correctly that you might want to keep them in a dedicated species aquarium. They're perhaps one of the only characins which we can say has a real individual "personality", which makes them "worthy" of such a committment!

I hope I've encouraged you to search for these amazing fishes...or to consider setting up a dedicated, carefully-configured biotope-inspired aquarium for YOUR "Holy Grail" fish.

Yes, my photos suck. And yes, I am geeked out about this fish. And, need to try them. Build an entire aquarium around them.

And yes, if you do, I'll hit you up for better pics! 😍

If you're looking for that "it" fish that will really make your botanical-style aquarium "pop"- adding a real presence and interest to the habitat you've created- give some real consideration to this wonderful fish- if you can find it! 

Trust me, having the "Guardian of The Spring" in your aquarium is worth the wait! Your botanical-style aquarium needs this fish! It's that cool.

Of course, it's one of many amazing fishes swimming in the tropical waters of the world; one which you as a hobbyist could dedicate and entire setup to, and never get bored or even remotely tired of...really. 

Yes, we all have that one fish. It's what keeps us passionate about the hobby; keeps us going. Keeps us dreaming, striving, searching.

Find yours. 

Embrace it. Love it. Share your work.

Stay persistent. Stay diligent. Stay resourceful. Stay passionate. Stay relentless...


And Stay Wet.


Scott Fellman

Tannin Aquatics 

August 18, 2019


Easing into it...

This hobby that we love so much is really supposed to be...relaxing, right? 

Yet, for some of us, what may qualify as relaxing is shockingly stressful for others!

Do you know one of those fish people who just "freaks out" every time you find a snail in your planted tank, or see a little spot of algae, or- perhaps-maybe-just that the tank doesn't look "right" this morning (even though it looks the same way it did yesterday morning...)?

Or, are YOU that person?

I think I used to be.

Sort of.

I was one of those fish geeks who, upon seeing some little "problem" in one of my tanks- say, a piece of wood slightly askew, or an aggregation of sand blown into one area by a powerhead-would freak the f--- out and have a towel down on the floor and sleeves up, and be "in contact" with the water in like under a minute to "correct" the issue!

Like, "Drop everything!!!!"

Yeah, my fishy friends thought I was a bit "overly-reactive" when it came to my tanks.

And I admit, I probably was.

And I think the origins of this aquarium behavioral "issue" could be traced back to the days when I had my aquarium(s) in my bedroom as a kid...One of the "conditions" my mom placed on me was that everything and to look "presentable" at all times...And of course, I quickly learned that "presentable" to a mom is far different than "presentable" is to a 14-year-old fish geek with 7 tanks in his bedroom, and that compliance was...well, really freaking important if I were to ever get that 8th tank in there!

Survival skills. That's what it was about. It's sort of guided my thinking in the hobby for a long time.

So I learned to deal with "small problems" quickly and efficiently. Always did- even as a "grown up." 

However, there was this...thing...that would happen when I "dealt" with stuff in my tanks. You know- those "small problems" that would crop up from time to time.

And of course, many of these "small problems" led to me rationalizing the "need" to make "one more adjustment" to the wood stack, or a little trim of this coral or plant...or maybe tweaking the orientation of a couple of pieces of rock... ("Well, I'm already IN there...")

Easy stuff, right?

I became a sort of "perpetual editor", if you will,  of my aquariums! And it was really easy to lose myself in these "little projects." 

Stuff that innocently starts at 7:30AM and results in a four hour, call-in-sick-to-work,  "5-towel project" of serious proportions. FYI, I often refer to the number of towels required for a project as a "measure" of its seriousness and complexity- a pretty good measure, IMHO! A "1-towel project" would be something easy, like shaking a piece of errant plant debris from the filter intake, whereas a "3-towel project" would be something like a water exchange/internal algae scraping/filter cleaning and media replacement.

A "5-towel project" is an all-hands-on-deck, "man your battle stations!" sort of prospect! You know, the innocent "I just have to move that one piece of wood" thing that starts out innocently and morphs into an all-morning, mind-bending "total re-do" sort of thing- new look, empty tank, stuff everywhere...Full-on "restart" mode. You really didn't want to be around me during a "5-towel project" back in those days.

Yeah, those "5-towel projects..."

I think that since I really dedicated a huge part of my fish keeping life to the blackwater/brackish, botanical-style aquarium genre, I learned to relax...a lot. The reef keeper in me still has a very serious side who wants things "just so", and who wants to keep his tanks "visitor ready" at all times, but with the cool vibe and natural aesthetic of our kind of aquariums, it's a lot easier to "explain away" the small patina of algae on the wood; the biofilm on the botanicals, or some decomposing leaves- part of the deal, and something that actually can educate the uninitiated about our strange, yet earthy obsession!

So, yeah, I suppose you could say that natural, blackwater/brackish, botanical-style aquariums have made me a lot less of a drama queen about my hobby. I mean, it's such a chill vibe and almost yoga-like approach to aquariums that you kind of can't help it! And it really doesn't matter how complex the "job" is- or how unusual the 'end product" is- it's enjoyable and chill!

And, once you look at enough underwater pics or videos of flooded igapo forests in Brazil, you kind of come to the realization that all of this stuff- the detritus, the biofilms, the decomposing leaves, tinted water- all of it- is simply the way many natural systems look, and that you are working WITH nature, rather than resisting it.

Nature seems to find ways to do stuff way better than we can- even though it may not always fit the "conventional aquarium definition" of beauty. And once you accept this, you'll find yourself creating aquariums that actually try to replicate what you once thought was "ugly."

You come full-circle.

That little "imperfection" you see in your tank, which used to cause such stress, is just Nature doing her thing as part of a cohesive whole...and an existential crisis is easily averted when you make this "mental stretch" and understand just what this botanical thing is really all about. When you realize that it's all part of a process, a system- one that was perfected billions of years before you were born- you'll get it.

It's mind-blowing. Humbling. And altogether inspiring. 

The stuff that used to send me into "red alert" mode is simply not that big a concern in the grand scheme of things to me anymore. Accepting this- appreciating this- changed my perspective on the way I keep aquariums forever.


Well, comparatively, lol.

I mean, I still hate water spills, clutter around my tanks, etc. I still like to keep the front glass clear at all times. However, if a piece of decomposing Mangrove leaf is blowing into the current, or a piece of wood has a strand of biofilm on it...I chill.

No freak outs.

No existential crises!

Of late, the "everyday challenges" of maintaining this type of aquarium are simply making sure that everyone is healthy, and that all the equipment is functioning nominally. You know, the usual stuff that most aquarists do. Sure, I still worry about the new fishes that I added, or if that small female Dicrossus is getting her fair share of food- but these are the inescapable, common parts of the game of aquarium keeping- and they'll continue to crop up wether your water is bright white and clear or dark, tinted, and murky.


It's how you approach this stuff that is the difference.

A lesson taught to nature.

Ease into it. Love it.

Stay chill. Stay calm. Stay cool. Stay engaged. Stay proactive. Stay healthy...

And always...Stay Wet.


Scott Fellman

Tannin Aquatics

August 17, 2019


The underwater "garden": Meeting Nature halfway...

Our art is truly one where we set the stage, and Nature does most of the "heavy lifting", right?

We work in tandem with her to create a collaboration of at and science...

"The garden suggests there might be a place where we can meet nature halfway."-Michael Pollan

An aquarium is very much a "garden" of sorts, isn't it? It's a well-worn analogy, yes. But fitting for what we do.

And I'm not simply referring just to a well- managed, planted system, either. To me, the "garden" part is that it's a little microcosm of nature, although not necessarily a perfectly manicured, high-concept, "ratio-correct" planted aquarium design. Reef tanks, botanical-style tanks, African cichlid tanks, etc. There are a lot of these kinds of concepts.

Each one has something in common: An acceptance and appreciation for a variety of life forms- plant and animal- working together to create a closed ecosystem. Each life form a valued component of a greater whole...much like a "garden", indeed.

As we're progressing in the art and science of more natural, botanical-style aquariums (blackwater and otherwise), we are seeing so many hobbyists are accepting and utilizing various elements of Nature in their aquascapes, and not over-thinking it.

Okay, I'm getting a bit philosophical again today. I know, I do it a lot. Yet, perhaps,  it's good for us to look at what we do in the hobby in a more introspective light.

One of the things I find "liberating" about the natural blackwater, botanical-style aquarium is that it teaches us to accept our aquariums where they are- and to look at nature as it is- not necessarily as we idealize it. As we have reiterated many times, the idea of putting terrestrial botanical materials into water creates not only varying environmental conditions, but an evolving aesthetic as well.

When you accept that seed pods, leaves, and other botanical materials begin to soften, change shape, accrue biofilms and even a patina of algae- the idea of "meeting nature halfway" makes perfect sense, doesn't it? You're not stressing about the imperfections, the random patches of biofilm, the bits of leaves that might be present in the substrate.

Sure, there may be a fine line between "sloppy" and "natural" (and for many, the idea of stuff breaking down in any fashion IS "sloppy")- but the idea of accepting this stuff as part of the overall closed ecosystem we've created is liberating.

It's liberating because we are not allowing ourselves to fall into the trap of other people's guidelines and "rules" about what goes where, or how many there should be, etc. Now, there is nothing wrong with a concept, or even a "design" for an aquascape- I think that's really important. However, where I think it's critical to our success is the point where we lay out a basic idea, bringing our sense of design to it- and then let nature "fill it in" a bit.

You select the materials you like, arrange them in an attractive "hardscape" that you like, and then accept that nature will "modify" them as she sees fit. By NOT allowing ourselves the "luxury" of freaking out every time a leaf is out of place, or a spot of algae appears on a piece of wood, we are learning to work WITH nature, rather than push against her.

When you look at those amazing pictures of the natural habitats we love so much, you're literally bombarded with the "imperfection" and randomness that is nature. Yet, in all of the "clutter" of an igapo flooded forest, for example, there is a quiet elegance to it. There is a sense that everything is there for a reason- and not simply because it looks good. It IS perfect. Can't we bring this sense to our aquariums? I think we can...simply by meeting nature halfway.

I was thinking about this the other day while reminiscing about my favorite home blackwater aquarium from a couple of years back. There was just "something" about that tank...Ever had an aquarium like that? I couldn't exactly put my finger on what I loved she much about it...Everything just sort of came together beautifully and naturally.

Specifically, I was recalling the  accumulation of biofilm and gasp- algae!- that would appear on parts of the mangrove branches which formed the foundation of my 'scape. The "patina" the water had...And rather than be repulsed and have this urge to reach for the algae scraper or siphon hose, I consistently found the look to be utterly tranquil, natural-looking, and beautiful in that random way which only nature can create.

I look back incredibly fondly on that tank!

What's more, seeing fishes like Nanostomus eques and Dicrossus filamentosus picking contentedly at the biocover between feedings made me realize that what bothers many of us aquarists is of no consequence whatsoever to our fishes. Rather, they accept it as a part of their world which has been with them from day one. They utilize it as a feeding ground. A place that they are naturally drawn to, engaging in ingrained behaviors that are a result of eons of evolution. 

And I thought to myself, "How strange is it that we spend some much concern, time, money, and effort trying to eradicate some of the very things which our fishes have embraced for eternity?" And further, I couldn't help but consider what audacity we have as humans to feel the need to "edit" nature to fit our own aesthetic "sensibilities!"

Now, I realize that there are many who will take issue with my thinking. Many who would suggest that I am the one who's being dogmatic, and that it's open for us to enjoy our aquariums how we choose. And of course, I'm 100% in agreement with that! Never said it isn't. Do YOU. You no doubt envision "beautiful" I na different way than I do...and that's okay.

However, what I find interesting is that, in many decades of aquarium keeping, we have been "counseled"- even chastised- by our community to keep aquariums free from visible algae, to remove any and all detritus, and to arrange and manicure plants in such a way as to embrace specific "design principles"- all the while spurning the very processes- and the aesthetics- of what nature actually does underwater. 

It's just sort of a "dichotomy of inconsistency", IMHO.

Not necessarily "bad"- or "good"- just...interesting.

Like, it seems to me that we've worked so hard to create some idealized, "clean" version of nature, that we've ended up in some cases creating the incorrect impression to many that nature is this perfectly ordered "fantasy world" that we've concocted. I think we need to be a bit more careful in how we present our work to the non-hobbyist crowd.

Again, it's my skewed opinion, but I think it's a valid point.

To me, the art of aquascaping is not only creating the wonderful designs which so many hobbyists do- it's also the ability to convey the wonder of how nature really is. Granted, in the end, we're trying to recreate our own, scaled-down version of The Amazon in a glass box- but the idea of re-creating- both aesthetically, and perhaps functionally- a "slice of the bottom", as they say- is incredibly alluring.

And never possible to do it more realistically than it is today.

Sure, we can't get every functional detail down- every component of a food web- every biochemical interaction...the specific materials found in a typical habitat- we interpret- but we can certainly go further, and continue to look at nature as it is, and employ a sense of "acceptance"- and randomness-in our work. 

Perhaps the aquarium- much like a garden- really IS a place where we can "meet nature halfway."

I think it is.

Stay open-minded. Stay proud of what you've accomplished. Stay creative. Stay studious. Stay thoughtful...

And Stay Wet.


Scott Fellman

Tannin Aquatics 



August 16, 2019


Can you start your aquarium hobby with a botanical-style aquarium?

We all have to start somewhere, right?

In the hobby, it usually involves some simple steps- a small aquarium, basic equipment...and big dreams, right?


We all dream of having that elusive "slice of the bottom" in our living room..That "thing" everyone seems to aspire to in the hobby. And some of us do actually get that. Eventually.

Now, as you recall, I recently celebrated the mindset of a beginner...that hopeful, appreciative, excited, often beautifully ignorant condition where everything is possible, and you're so taken by the adventure and beauty that you operate in a "bubble" of innocence...


So, here we are in "Tannin World", throwing out sexy images of exotic tropical blackwater locales, deeply tinted aquariums filled with spawning fishes, etc.

You know, kind of "selling the dream", right?

Lots of hobbyists are finding this compelling, interesting, and want to give it a go in their own tanks, for which we are grateful.

And, more and more often, we are visited and patronized by people who are at he very beginnings of their aquarium hobby journey...That's a nice way of saying outright beginners...

Now, "beginner" doesn't mean "stupid, easily-manipulated person with more money than common sense" or something similar. However, a "beginner" is defined as "a person just starting to learn a skill or take part in an activity."

Just starting to learn.

As we always say, the learning part of the aquarium hobby never stops. I've been in it literally since I could walk, and I'm still learning stuff every single day. There are tons of things I'll never even begin to understand in the hobby. I make mistakes all the time. Part of the game. You can't know everything and do it perfectly from the start. Or, ever. It's almost impossible for any single person to know everything that there is about tropical fishes and aquarium keeping.

However, you can specialize in something early on that catches your fancy, and become a serious, ultra-experiences speciality know, like a cichlid breeder, Betta keeper, aquatic plant enthusiast, etc.

The key is learning some fundamentals, first, right? You have to walk before you can run...all of that cliche shit.

So, where was I going with this?

Oh, yeah. 

So, when we are approached by outright beginners in the aquarium hobby- people maybe keeping their first ever aquarium, or even some who are even "pre-aquairum", I have mix of emotions. On one hand, I'm stoked that they are open-minded and fascinated by our approach, and about Nature. A lot of times, the discussion begins with the hobbyist writing that noble line, "I want to give my (insert popular fish here) the best possible environment..."

That's a really great sign.

It's also a sort of "red flag" for me. I mean, stoked as I am- I'm equal parts scared shitless that someone is so enamored by the look and vibe of botanical-style blackwater aquariums that they may not understand the very "counter-culture" sort of way they know, the idea of creating a very different set of environmental conditions for fishes than the "plug-and-play" sort of habitats we tend to push beginners into.

So, yeah, I get a little freaked.

I mean, on the surface, we're telling people to add all sorts of botanical materials to their aquarium, which, in simplest terms, are definitely a form of "bioload"- material which adds to the "burden" placed on the beneficial bacteria which break down biological waste and organics. You know- the nitrogen cycle thing. You HAVE to have a grasp on this stuff... And it wouldn't hurt to learn about the idea of "food webs" in aquatic systems, either... a real "unlock" if you make the effort to study them.

And of course, we strive to educate beginners about the nitrogen cycle in the hobby right? RIGHT? DO WE? 

I hope so. It's so fundamental that it would be insane if we didn't. It's like the key to everything. I know we teach them a little about slowly stocking a tank, about water changes, filtration, etc.

However, when I see some of the questions asked by outright beginners on various Facebook groups or wherever, I sometimes wonder. Are we so good at presenting "Parts C, D, and F" that we forget to really reinforce the lessons of "A and B" to newbies? Like, they just want "Instant Orinoco" without having a really good grasp on how to do a water exchange or feed fishes. Or more important- WHY to perform these basic tasks. 

Like, understanding the basics of aquarium management is probably not nearly as exciting as finding the right piece of rock or driftwood for you tank, but ignorance of it will pretty much f-ck your entire adventure up from the start if you don't grasp these less "sexy" topics. We all know this. I hope that we all tell beginners this cold, hard truth. It's for the best.

And so, beginners will approach me about creating "great natural conditions" for "Ralph" the Betta, and I sort of gulp a bit. I mean, one assumes that when people want to create a botanical-style/blackwater or other type of natural aquarium system that they have at least been exposed to other types of more simplistic, straightforward approaches to aquarium keeping.

Yet, it's dangerous to assume. And in this "Instagram-fueled" age of superficial imagery over substance, it's easy to see what a truly "green" hobbyist could be enamored by this stuff and just want to zero in on it. It looks cool, sounds like "the right approach", and generally seems good, especially if the aesthetics and the look of wild habitats call to them.

So, what to do? 

Well, I'm fairly proud of the enormous volume of information- unruly though it may be these days- that we have created here for hobbyists on virtually every aspect of our approach. It's all there. Maybe not the best-organized at the moment...but it's there! You have to dig. Just like you have to google "How the nitrogen cycle works.." or whatever. Seeing a theme here?

Yeah. It makes me feel good that we have a lot of very non-sugar-coated information in our "library" about our approach, the good and the bad. If anyone ever calls B.S. on us about this stuff, they haven't read deep enough. 

I suppose at some point, we may even do a series of articles aimed at less experienced hobbyists. Notice that I didn't say "beginners"- because a beginner needs to learn the very basic hobby principles and practice them, real-world style- first.

If I suspect someone is a super beginner, I'll at least give them the cursory advice to read as much as they can and go very, very slowly before playing with this stuff. I've actually gone so far as to suggest some people just wait until they have more experience with aquariums before even playing with botanicals. Each time, it was NOT received well, to be perfectly honest, as you might imagine.

I think it's a cultural thing, right? What led the newcomer to us was the cool look that somehow resonated with them. I get it. I appreciate it. And of course, I understand the responsibility that goes with it, and the responsibility we have a s a company to tell new hobbyists that this stuff, while not difficult- has lots of variables, "best practices", and responsibilities, all of which the hobbyist who "treads in our tinted waters" needs to at least have a basic familiarity with, if not, understanding of.

We seem, as society, to be more self-assured and emboldened about knowing how to do everything that we see online. As if there is always a "hack" or shortcut to success that allows you to get to the "desired" result by skipping all of the "boring" stuff.  Gear. Additives. Monitors. Such "workarounds" are a foundation of our modern, "I-don't-have-time-for-the-details-just-get-me-to-the-main-event" lifestyles. And that is not good in a hobby like ours, which is centered around taking care of animals in a closed ecosystem.

And it takes learning and grasping fundamentals.

We, as a hobby, need to really double down on educating beginners. Not in a condescending or "preachy" sort of way, but out of concern for their long-term success and well-being I the hobby..and for the well-being of our fishes! It's about responsibility, education...patience. 

So, can a beginner keep a botanical-style aquarium for his/her first tank?

I suppose so, if he or she takes the time to understand these fundamentals. Of course, the dynamics of fostering decomposition, fungi, biofilms, lower pH, water quality management, etc all require a degree of dedication, skill, and above all...patience.

If you are just get started in the hobby and want to keep a botanical-style aquarium, please make the effort to understand the dynamics of the nitrogen cycle. Learn about how metabolic wastes and dissolved organics are handled by the bacteria and other organisms that reside in your aquarium, and how the stocking levels, the speed at which we stock, and the way we manage our tank all are impacted by this dynamic.

Make an effort to learn about the natural habitats which we seek to replicate in this speciality niche. They have dark water, lots of leaves, and decomposing plant parts for a reason. You need to be aware of the topography, the weather, and the outside factors that influence the environment surrounding these aquatic habitats. And you need to understand why fishes are found in them. You need to almost take a more "holistic" approach and mindset than you do with many other types of aquariums, in order to really grasp this stuff and be successful.

It's really not as simple as "toss in a few leaves and you have a blackwater aquarium..." You need to understand pH, hardness, and TDS, as well. The misconception that tossing in leaves into your aquarium filled with hard, alkaline tap water will give you "Amazon" conditions is one of the absurd "myths" that has been perpetuated for decades by those who (let's not sugar coat it) are completely clueless and have made no effort to understand these basic concepts.

You have to dig. You have to learn. You'll have to be patient. You have to experiment. You have to prepare. And you have to move slowly, carefully, and thoughtfully.

If you don't couple these principles and basic skills together with your use of botanicals, you'll kill everything in your aquarium. Quickly. Full stop.

Still interested after that rosy picture?


The best news here? It's not that difficult. It's not onerous. None of this is rocket science, or some great mystery. It just involves coupling basic, long-perfected aquarium principles and practices with patience, observation, and these funny looking seed pods and leaves.

Put all of those things together, and you're well on your way to a very satisfying, educating, and altogether different aquarium experience. 

So, before you hit "add to cart" when you see that interesting-looking seed pod or leaf on our site, or elsewhere- just consider what's involved. Think about the impacts of adding botanical materials to closed ecosystems, and how you have to mange them.

If you're up for it...if it really speaks to you...if you like the learning, experimenting, and sharing. If you love this look, this concept...

Go for it. Dive right in.

After you're certain you've got a grasp on the basics.

There is so much more. Welcome to our tinted, earthy, uniquely natural world. We're glad you're here. We hope you stay a while...

Stay curious. Stay inquisitive. Stay diligent. Stay open-minded. Stay excited. Stay patient...

And Stay Wet.


Scott Fellman

Tannin Aquatics 





August 15, 2019


The art of "the art.." Easing into blackwater...

I realize we push you guys pretty hard...

We push you to look at natural aquatic habitats and create aquairums that are, in many cases, literal interpretations of them. Not just in terms of the "look", but in terms of the functions and the interactions between fishes and their environment that they foster.

Now, I realize- and have from day one of Tannin, that not everyone likes the look of a truly natural aquarium. You might not even agree with us that flooded forest floors and other blackwater systems are all that compelling...

Oh, sure, some people like a couple of seed pods, maybe a leaf or two, and possibly even the tinted water. However, you may not like the look of decomposing botanical materials, biofilms, and detritus. Some of you favor a more "artistic" look overall. And some of you perhaps like the tinted water- you just don't want the other stuff...

As I've said like, thousands of times- I totally get it.

And, even Nature provides some inspiration for a less "botanical-laden", yet still "tinted" look.  You just have to look. IN the pic below, the water is tinted, but there is nary a leaf in sight...These materials are upstream, and the soils which impact the tint are everywhere...There are numerous influences on the color of the water- clues for us to take from Nature, right?

Just because you don't like the "all-in" natural look doesn't mean that you can't enjoy some aspects of this world. You simply need to approach things a bit differently.

I can relate.

I mean, I love "artistic" 'scapes.

I like the look of an amazing "Iwagumi" scape, with a perfectly manicured lawn of Glostostigmma or Dwarf Hairgrass, or some other "high-concept" planted tank but I will likely never personally set one up. They just don't hold an allure to me that makes me want to jump in and do one. I'd love to HAVE one, but the "art" of it is not my thing. And, I don't have the patience or particular set of skills required to accomplish that. (So, perhaps that's a slightly different issue than what I'm alluding to here, lol...but the overriding concept is the same. )

I like the idea- admire the product-yet, just not all aspects of it.

However, you likely have the skills to create a very natural-looking tank...You just may not like all aspects of the look itself.

And that makes perfect sense.

So, lets say that you like the tinted water. You might even like seeing some botanicals in your tank. But not- the decomposition-it's not your thing. How would you pull it off? 

Easily, actually. 

You could start by utilizing some botanical materials in your filter. Like, just "sandwich" a piece of catappa bark between some mechanical media, where water will flow through it...Guess what? The bark will impart its tannins and humic substances into the water...You'll get a nice "tint" without ever seeing a bit of bark or other aspects of the botanicals in your tank! You could have a spotlessly clean, yet tinted tank! 


And, unlike having to continue to dose liquid "blackwater extracts", it's a lot easier to utilize the actual botanical "source" itself, as it will "time release" the tannins for some extended period before it becomes more or less "inert." Don't believe me? Think about the last time you cured a piece of sexy driftwood in your tank...How long did it take before the water was "clear blue/white" instead of golden brown?

Yeah. A long F- #$%ING TIME! 😂

For many hobbyists, this is a great way to ease into the world of blackwater aquariums, while still creating the overall "look" or style that you love. It's a form of compromise, I suppose- but one which will perhaps unlock new ideas and aesthetic inspirations for you.

Another approach to "easing" into the world of botanical-style, blackwater aquariums without the "whole natural thing" would be to utilize more "durable" botanical materials- ones which tend to not break down too much...or break down very, very slowly over an extended period of time. So, you could utilize materials such as Sterculia pods or Cariniana pods, which have a very hard external "construction" and tend to soften extremely slowly.

If they begin recruiting algae or biofilms on their surfaces, you can simply remove them and scrub them gently with a soft bristle brush (like a toothbrush), give 'em a rinse, and return them to service. A bit more labor intensive than keeping a piece of bark in your filter, but it gets you the added benefit of an aesthetic boost, courtesy of the seed pod itself! 


What about leaves? 

You can also use leaves...Yeah, leaves are certainly more ephemeral, but you could utilize them in your tank to get the "look" of a leaf litter bed or accumulating leaves, without some of the other aspects (like, biofilms and complete breakdown/decomposition).  I'd likely avoid guava or catappa leaves, which tend to break down fairly rapidly in most systems.

So the key to utilizing leaves in the easiest possible manner is to select some leaves that are more durable- like Yellow Mangrove, or Texas Live Oak leaf litter  (if you're a bit more adventurous, and don't mind either using all of the other materials which come with it- or sorting through the mix to remove only the leaves). Both of these leaves are durable, and will last many months, as opposed to weeks (as in the case of other leaves) before breaking down.

And of course, if you like leaves and such, but DON'T like the "tinted" look they impart into the water, you can always utilize activated carbon or other chemical media, such as Seachem Purigen, to remove it. When combined with your usual frequent water exchanges, and removal/replacement of leaves as they break down, this practice can give you the "look" indefinitely.

It's simply a matter of how hard you want to work at it...And it's not really "work"- it's simply a matter of incorporating the process of replacing leaves into your regular maintenance procedures.


This approach is very successful, and has been executed beautifully a number of times by our friend, the talented Jeff Senske, legendary 'scaper and co-founder of  Aquarium Design Group.  If you're inspired and motivated, beautiful aquaecapes with botanicals are entirely achievable in this fashion.

It's about compromise, education, observation, and procedure. Clear or tinted- planted or unplanted- you have numerous options when it comes to utilizing botanical materials in your tanks.

There are many approaches to using botanicals in your aquascaping work besides making them the central focus of your ecosystem, like we do so often here. Our approach is just one way to use botanicals. Certainly not the "best way"- but an approach that you may or may not find appealing.

You can have the "artistic-style" tank that you like, while still easily incorporating some aspects of the botanical-style aquarium into the mix. The main "rule" is that there are no "rules"- except those dictated by Nature herself.

It's about creativity, imagination, diligence, and executing...About freeing yourself from preconceptions and daring to go down a different path.

That's the "art" of the art.

Until next time...

Stay creative. Stay observant. Stay diligent. Stay consistent. Stay obsessed...

And Stay Wet.


Scott Fellman

Tannin Aquatics 



August 14, 2019


The "physical/structural" aspect of aquascaping...

Our art of creating natural-style botanical-influenced aquariums is constantly evolving, with new techniques and applications for botanical materials being worked out by hobbyists worldwide daily. As more and more hobbyists utilize the abundance of materials that Nature offers to create unique aquariums, the collective "body of work" and "best practices" of our craft move right along with it. 

Now, curiously- the one thing that hasn't noticeably "evolved" during the time we've been playing with this stuff is...our fishes! I mean...they kind of do what they've done for eons in their aquatic habitats, right? They are remarkably adaptable creatures, particularly when it comes to their physical surroundings.

Yeah, let's face it; pretty much no matter how we 'scape a tank, our fishes will ultimately adapt to it. They are really good at it...They'll find the places they are comfortable hiding in. The places they like to forage, sleep and spawn. 

It's what fishes do. It's what they've done for eons.

And as aquarists, what we've done for a century or so is try to create optimum conditions for the fishes we keep. This, of course, encompasses both the chemical and "physical/structural" environment. We've talked a lot about the chemical environment, vis a vs our botanical-style blackwater systems. You've heard me bandy about the term "functional aesthetics" many times before. Today, let's just think for a few moments about the "physical/structural" environment we create for our fishes, the role that it plays in their lifestyles, and why.

And of course, how to apply this knowledge to our aquarium practices!

When we're planning an aquascape, we spend an enormous amount of time selecting the right materials: Rocks, wood, botanicals, etc., to get the right "feel" to our 'scape. This is, for many of us- a most enjoyable and interesting phase of an aquarium build, for sure! Yet, it's very easy to sort of "reinvent the wheel" attempt to "edit" the way Nature looks, and attempt to configure an aquarium based on factors having less to do with an unfiltered version of Nature and more to do with an artistic interpretation of Nature that is often glorified in the hobby.

Yeah, it is!

Now, take yourself out of the "I'm-gonna-enter-THIS-ONE-in-the-aquascaping-contest-and-place high" mindset for just a second, and put yourself into the mindset of...a fish.

Yup. Think like a fish for just a second. 

I mean, sure, I'll bet that fishes like living in those insanely cool 'scapes you see in all of the contests; however, those are mainly designed and constructed for the pleasure of humans, right? They're designed for our tastes. Specifically, for human "judges", who evaluate a design-based on a set of specific criteria, which only my extreme levels of self-restraint and tact and decorum keep me from criticizing in a "scorched earth" fashion, I might add.  I mean, "Iwagumi" looks really cool, but I'd hazard a guess that you won't find many of these "submerged Stonhenge" features in the natural streams and rivers of the world.

I'm just gonna go out on a limb and make that speculation...

What would be a better approach to more "natural" aquascaping? How about considering just how the fishes will actually live in and interact with the aquascape you create? 

My suggestion on how to pull this off effectively?

Again: Think like a fish a bit more.


It might be kind of fun-and educational- to think about where your fishes are found in the natural streams, lakes, flooded forests, and rivers they come from...and "work backwards." I mean, fisherman have been doing this for eons...why not fish hobbyists?

Makes a lot of sense, right?

Yeah, I think so!

Let's look at some of the features in natural bodies of water where fishes are commonly found...this might give you some insight into how to incorporate them into an aquascape. We can kick off this process with a very cursory look at rivers and streams, where a good chunk of the fishes we keep in aquariums seem to come from. 

Here are just a few of the many features of streams and rivers that fishes LOVE to congregate in...Think about how you might consciously incorporate some of them into your next aquascape!

First off, a few "sweeping generalities."

Fishes tend to live in areas where the food and protection is, as we've talked about previously. Places that provide protection from stronger current and above-and below-water predators. Places where they can create territories, interact, spawn and defend themselves.

Bends in streams and rivers are particularly interesting places, because the swifter water movement will typically carry food, and the fishes seem to know this. And if theres a tree branch, trunk, or a big rock (or rocks) to break up the flow, there will be a larger congregation of fishes present. So, the conclusion here is that, at least in theory, if you design your scape to have a higher "open water" flow rate, and include some features like rocks and large branches, you'll likely see the fishes hanging in those areas...

In situations where you're replicating a faster-flowing stream environment, think about creating some little "rock pockets", perhaps on one side of the aquarium, to create areas of calmer water movement. Your fishes will typically orient themselves facing "upstream" to catch any food articles that happen on by. So, from a design perspective, if you want to create a cool rock feature that your fishes will likely gather in, orienting the flow towards it would be a good way to accomplish this in the aquarium. 


Among the richest habitats for fishes in streams and rivers are so-called "drop-offs", in which the bottom contour takes a significant plunge and increase in depth. These are often caused by current over time, or even the accumulation of rocks and fallen trees, which "dam up" the stream a bit. (extra- you see this in Rift Lakes in Africa, too...right? Yeah.) 

Fishes are often found in drop offs in significant numbers, because these spots afford depth (which thwarts the hunting efforts those pesky birds), typically slower water movement, numerous "nooks and crannies" in which to forage, hide, or spawn, and a more restive "dining area" for fishes without strong currents. They are typically found near the base of tree roots...From an aquascaping perspective, replicating this aspect of the underwater habitat gives you a lot of cool opportunities.

If you're saddled with one of those seemingly ridiculously deep tanks, a drop-off could be a perfect subject to replicate. And there are even commercially-made "drop-off" tanks now! Consider how a drop-off style encompasses a couple of different possible niches in the aquarium as it does in Nature!

Overhanging trees and other forms of vegetation are common in jungle/forest areas, as we've discussed many times. Fishes will tend to congregate under these plants for the dimmer lighting, "thermal protection", and food (insects and fruits/seeds) that fall off the trees and shrubs into the water. (allochthonous input- we've talked about that before a few times here!) And of course, if you're talking about a "leaf litter" or botanically-influenced aquascape, a rather dimly-lit, shallow tank could work out well.

And of course, in the areas prone to seasonal inundation, you'll often see trees and shrubs partially submerged, or with their branch or root structures projecting into the water. Imagine replicating THIS look in an aquarium. Contemplate the behavioral aspects in your fishes that such a feature will foster!

Lots of leaves, small pieces of wood, and seed pods on the substrtae- doing what they do- breaking down-would complete a cool look. For a cool overall scene, you could introduce some riparian plants to simulate the bank as well. A rich habitat with a LOT of opportunities for the creative 'scaper!

Why not create an analogous stream/river feature that is known as an "undercut?" Pretty much the perfect hiding spot for fishes in a stream or river, and undercuts occur where the currents have cut a little cave-like hole in the rock or substrate material near the shore.

Not only does this feature provide protection from birds and other above-water predators, it gives fishes "express access" to deeper water for feeding and escaping in-water predators!

Trees growing nearby add to the attractiveness of an undercut for a fish (for reasons we just talked about), so subdued lighting would be cool here. You can build up a significant undercut with lots of substrate, rocks, and some wood. Sure, you'd have some reduced water capacity, but the effect could be really cool.

Aquascaping, as we've come to know it in the hobby- is part art, part science, and every bit an interpretation of the natural world. Although we spend enormous amounts of time and energy encouraging you to look at and replicate the form and function of Nature, it is a hobby- and you should do what moves you. Yeah, in the end, design and build the aquascape that makes you happy, regardless of the "style" or "design theory" that you embrace.

However, if you're trying to create something just a bit different and perhaps a bit more true to Nature, you might want to take a little "field trip" to a nearby stream, river, creek, lake, etc., where fishes and other aquatic animals reside, and observe things from the perspective of how they interact with the features of the environment. 

At the very least, it might open your eyes a bit and give you a different perspective on the way wild aquatic habitats evolve, function, and host fishes.

You should "get outside" and do this once in a while! You'll definitely leave with some inspiration, ideas, and just maybe, a slightly different perspective on aquascaping than you've previously had! You'll notice subtle details which, when applied to an aquarium, could provide an amazingly unique look and function for your fishes!

And in the end, gaining a fresh perspective and new inspiration for your hobby is never a bad thing! So, "thinking like a fish" isn't such a bad idea, is it?

Stay curious. Stay inspired. Stay creative. Stay inquisitive. Stay bold. Stay objective. Stay focused...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

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