June 15, 2019


Accepting the "challenges"...if you want to call them that..

I think that the biggest challenges in creating a botanical-style aquarium involve the processes- that is, understanding and accepting the processes which occur to get one of these systems "broken in" and thriving. Now, none of the stuff we do is difficult, from a "procedural" standpoint; it's mostly "just prep, place, and wait." The hard parts are deploying patience and making the mental shifts required in the botanical-style aquarium game..

The mental shifts being (for the millionth time, right?) acceptance of a different aesthetic, appreciating biofilms, tannin-stained water, detritus, and organic decay of botanical materials. Understanding that these are the elements of Nature, truly "unfiltered"- and that many (dare I say most?) natural aquatic habitats of the world incorporate several of these elements. Realizing that Nature is not the perfectly arranged, color-coordinated, "golden-ratio"-driven environment that we as aquarists tend to interpret it as.

Back to the process, for a second.

Now, obviously, you're utilizing terrestrial materials in an aquatic environment. Seed pods, stems, leaves, etc. all tend to float initially when wetted. This is part of the reason why we employ a soak/steep/boil for most botanicals. Otherwise, if you just drop 'em in your tank, you'll end up with the botanical equivalent of the Sargasso Sea- a floating "salad" of botanicals topside!

These prep processes help saturate and sink the botanical materials. Some sink more easily and quickly than others. The more durable, "hard-shelled" pods can take an hour or more of boiling just to get them to stay down (I'm thinking about Cariniana Pods and Sterculia Pods here). Their tissues are hard and not the most porous, so the extended soak/boil/steep period is essential if you want them to sink. And of course, as touched on before, this will also release any pollutants bound up in the surface tissues of these botanicals.

Once the botanicals are no longer buoyant, they easily sink to the bottom of your aquarium. And of course, they will begin releasing tannins, humid substances, lignin, and other organic compounds that are present in their tissues. The tannins and humic substances which we covet are just a small part of what is rebased into the aquatic environment, and when you're adding a bunch of material to the aquarium, it's important to observe water quality. We always tell you to go slowly for this very reason- particularly in an established aquarium. These are "dynamic" materials.

After several days or a week, you will see the materials appear to "soften up" just a bit, and perhaps acquire a "patina" of biocover. Most likely, it's in the form of fungal growth and biofilms. These biofilms, in particular, are an incredibly important part of the aquatic ecosystem we aim to replicate in our aquariums, but their appearance is often outside of the aesthetic tastes and expectations of the uninitiated hobbyist!

Your fishes, of course, will have a slightly different opinion...

And of course, the tinted water that seems to accompany our use of botanicals...well, that's a BONUS, in my book! 

Yeah, this period is a part of the "game" where we can separate the hobbyists who understand what's really natural from those who have "not done their homework", so to speak. As we've discussed numerous times, biofilms are a completely natural and expected part of utilizing dried botanical materials in an aquarium. The "aesthetics" of this process is not everyone's idea of "beautiful"- and that's understandable.

However, it's a normal, natural, part of the game. 

Biofilms will always be present to some extent during the lifetime of your botanical-style aquarium. We need to accept this. During the initial phases, you have several options. You can physically scrub the biofilms off of the botanicals as needed (accepting the fact that they will likely reappear), or observe your natural "biological controls" (such as ornamental shrimp, snails, or even Otocinculus catfish) to help with this process.  

In fact, many fishes will forage upon biofilms as part of their diet. Although they are efficient, you shouldn't expect the animals to get everything, and you should not stock your tank with "scavengers" for the sole purpose of eliminating these growths. You can assist with the removal of any offensive materials or...wait it out.

The realization that it's perfectly natural and entirely consistent with the nature of these environments to have some of this stuff present is likely little comfort to you if you just can't handle looking at a field of "yuck" on your botanicals. I can't stress enough the need to make that "mental shift." As we discussed, management of this stuff is entirely up to you and what you can tolerate. Generally, the biofilms, fungal growths, and algae are self-limiting, ultimately disappearing over time as the compounds that fuel them diminish or attain levels that are not sufficient for their growth, or as a result of animals consuming them- or a combination of both.

Ultimately, if you continue to deploy patience and a healthy dose of good old-fashioned aquarium husbandry skill (ie; water exchanges, etc.), your aquarium will fall into a delightful "equilibrium" of sorts- with the botanicals regularly breaking down and transient appearances and disappearances of fungal growths and biofilms during the lifetime of the system.

And of course, that decomposition...the breakdown of botnaicals and leaves is an ongoing process. The decomposition of "transient" materials like leaves and softer pods, etc. is simply part of the natural dynamic, and will continue as long as you choose to employ these materials in your aquascape. If you observe carefully, you may note spawning and other "grazing" behaviors in your fishes, and note that they are spending significant time foraging though the broken-down matter, much like in nature.

Ultimately, the decision to create a "botanical-style aquarium is as much a philosophical one as it is a practical one. To accept nature, rather than to fight it, is a bit at odds with the mindset many of us have with regards to aquarium keeping. As you begin to understand and evaluate your own aquarium, you'll gain a greater appreciation for the wonders of nature, and the processes that have occurred for eons.

Challenge? Perhaps. But the rewards of accepting the challenges could be beyond measure. Rise up to them...

Stay bold. Stay diligent. Stay curious. Stay observant. Stay progressive. Stay enthralled...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

June 14, 2019


Fine-tuning "the practice..."

As a fanatic about truly natural-style aquariums; one who embraces the nuances of the wild habitats- the aesthetic, the function, the color of the water- you're very well attuned to everything that the use of botanical materials can bring to your tank.

Our "practice" of botanical-style aquariums is becoming more and more "mainstream" all the time, with hobbyists from all sorts of aquatic disciplines dabbling with, and incorporating botanical materials into their work. Some are doing it purely for the aesthetics; some for fish breeding, others for the adventure- and some simply want to do some cool experimentation!

When people ask me why I like to add leaves to my aquariums, I can probably give hem a dozen or more reasons why; among the most important is for the ecological "enhancements" they offer as they break down.

Regardless of YOUR rationale for adding "stuff" to your tanks, it's important to follow some basic "best practices" that those of us in the game for a while have learned- sometimes, painfully, I might add! One of those is to go SLOWLY when adding materials to an established aquarium.

I know, I know. We must have mentioned this literally 5,000 times in they blog and elsewhere- but it's fundamental to what we do.

It seems logical, but in practice, it's not always that easy to restrain ourselves, right? I mean, it's just a bunch of leaves and stuff...What could go wrong?

Well, a lot, if we're less than careful!

Think about what happens when leaves and botanical materials fall into streams and other bodies of water in nature.

When leaves fall into streams, field studies have shown that their nitrogen content typically will increase. Why is this important? Well, for one thing, scientists see this as evidence of microbial colonization, which is correlated by a measured increase in oxygen consumption.


This is interesting to me, because the rare "disasters" that we see in our tanks (when we do see them, of course, which fortunately isn't very often at all)- are usually caused by the hobbyist adding a really large quantity of leaves and botanicals at once to an established, stable aquarium, resulting in the fishes gasping at the surface- a sign of...oxygen depletion?

That makes sense, right? 

These are interesting clues about the process of decomposition of leaves when they enter into our aquatic ecosystems. They have implications for our use of botanicals and the way we manage our aquariums. I think that the simple fact that pH and oxygen tend to go down quickly when leaves are initially submerged in pure water during lab tests gives us an idea as to what to expect in aquariums..

Rapid changes. 

And to an aquarist, rapid changes in the environment = bad news.

A lot of the initial environmental changes will happen rather rapidly, and then stabilize over time. Which of course, leads me to conclude that the development of sufficient populations of organisms-beneficial bacteria- to process the incoming botanical load is a critical part of the establishment of our botanical-style aquariums.

Fungal populations are also important in the process of breaking down leaves and botanical materials in water as are higher organisms, like insects and crustaceans, which function as what ecologists call "shredders." So the “shredders” – the animals which feed upon the materials that fall into the streams, process this stuff into what scientists call “fine particulate organic matter." 

You know, "detritus" and "stuff in the water."

In studies conducted in tropical  rainforests in Venezuela, decomposition rates were really fast, with 50% of leaf mass lost in less than 10 days! Interesting, but is it tremendously surprising to us as botanical-style aquarium enthusiasts? I mean, we see leaves begin to soften and break down in a matter of a couple of weeks- with complete breakdown happening typically in a month or so for many leaves.

And biofilms, fungi, and algae are still found in our aquariums in significant quantities throughout the process- just like in nature.

The wild habitats that we are fascinated by are highly dynamic environments, and change continuously.  They're constantly evolving, accumulating new materials, and creating new physical habitats for fishes to forage among. These new food sources and chemical/energy inputs are important to the biological diversity and continuity of the flooded forests and streams of the tropics.

We replicate this process in the aquarium by adding new botanicals, conducting water exchanges, etc. The basics of aquarium husbandry and management haven't really changed in a century. And they are just as applicable to the botanical-style/blackwater aquarium as any other. The only real "difference" here is in the context- and how we understand what is actually going on and why.

Mental shifts.

We are not managing aquariums to be sterile glass boxes, "dioramas", or "zen gardens." It's not just a "look." We are understanding that a real "nature/natural-style aquarium" embraces the processes of nutrient import/export, decomposition, bacteria/fungal growth, and long-term nutrient utilization by the organisms which we keep. The appearance is far different than a system strictly set up for aesthetics. Rather, our systems offer a unique combination of form AND function...what we call "functional aesthetics."

The "look" and the "function"- working hand in hand to create a replication of Nature far more authentic than what we've done in the past in the hobby. And what is required to execute this?

Patience. A long-term view. Observation. Understanding.  

Stay studious. Stay patient. Stay diligent. Stay observant. Stay creative. Stay adventurous. Stay curious...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

June 13, 2019


Patience, measured moves...and...food webs?

The aquarium hobby will challenge you in every way. Push you, tease you, even taunt you at times. However, if you do things right; listen to Nature's clues...She'll reward you- often in ways that you never considered. 

It occurs to me that some of the best moves I have made as an aquarist were not as a result of jumping right into something...No, rather- the best moves I've made were consistently the result of smaller, slower, more measured moves...Stuff that took what seemed like eons to accomplish...And yielded long-term results that were well worth the wait.

Most of them are predicated on one simple idea:

"Radical patience!" 

What's 'radical" about patience? Is there some special meaning to this? Well, not really. It's as much about common sense as anything, actually. Yeah, common sense.

That is- not jumping right into something...taking a bit of time- or even a long time- to allow your aquariums to "run in" and develop before pushing them along. I mean, why are we always in such a hurry to get fishes in?

Having set up more than a few systems in my time, I never seem to be surprised at my own true hobbyist-style impatience!

Let’s face it—once we get the plumbing done, the lighting tweaked, leaks sealed, and aquascaping set, we’re all seemingly hell-bent on getting some fishes in there! I mean—we’ve waited so long for “first water” in the tank that it’s time to enjoy the fruits of our labor.

It's like we need to get the fishes in there right away…even just a few, right?

Can’t really blame us, huh?

However, there may be some compelling reasons to wait just a bit longer…

Would you like to move into a house which didn’t have a refrigerator full of food?  I wouldn’t, for sure. Unlike humans, fishes seem to have not lost their "genetic programming" for grazing and hunting for food. Let’s face it—most of the waking hours of aquatic animals are devoted to acquiring food and reproducing. They need to have some food sources available to "hunt and graze" for.

That’s reality.

So why not help accommodate our your animals’ needs by supplementing their prepared diet with some “pre-stocked” natural foods in their new home? You know, slow down, get things "going" a bit, and then add the fishes?

I’m not talking about tossing in a few frozen brine shrimp hours before the first fishes go in the tank—I’m talking about a deliberate, systematic attempt to cultivate some living food sources within the system before a fish ever hits the water! Imagine a “new” system offering numerous foraging opportunities for it’s new inhabitants!

And in our world, that might mean allowing some breakdown of the botanicals, or time for wood or other botanicals to recruit some biofilms, fungi- even turf algae on their surfaces before adding the fishes to the aquarium. 

“Scott. You’re being impractical here! It could take months to accomplish this. I’ve just spent tons of money and time setting up this tank and you want me to deliberately keep this tank devoid of fishes while the biofilms form and Daphnia reproduce?”

Yes. Seriously.

 I am a bit crazy. I’ll give you that. 

Yet, with my last few systems, this is exactly what I did. 

And you know what?

It works really well.

For years, I did this in reef tanks.. and as a result of the "Radical Patience" thing, I was keeping Pipefishes and Mandarin Dragonets- notoriously difficult feeders-in the tank from “stocking day one” in my last few reef tanks with no losses, and fat and happy fishes actively foraging for their natural food sources between regular feedings.

(Synchiropus splendens, the Mandarin Dragonet. Image by Luc Viatour. Used under CC BY-SA 3.0)

I’m no genius, trust me. I don’t have half the skills many of you do but I have succeeded with many delicate “hard-to-feed” fishes over my hobby “career.” 

However, I'm really f- ing patient.

Success is simply a result of deploying..."Radical patience."  The practice of just moving really slowly and carefully when adding fishes to new tanks. 

A really simple concept.

I mean, to some extent, we already deploy this practice with our blackwater/brackish, botanical-style tanks, right? The very process of creating a botanical-style aquarium lends itself to this "on board supplemental food production" concept. A sort of "food web" that's pretty analogous to those found in Nature, right?

And it plays right into the work that we regularly do as botanical aquarium fans...

For many fishes and ornamental shrimp, you "stock" your tank with some leaves and other botanicals and allow them to begin to break down a bit before stocking. Hardly a radical concept in our world; merely a simple "tweak" our typical way of doing stuff.

However, I'm always surprised at how a seemingly simple tweak can yield disproportionately great results! It's not like there is any special skill required in order to wait. I mean, it just requires self-discipline (and perhaps, the ability to stare into a tank devoid of fishes for just a bit longer, lol). And if you really plan right, like I did with my all-leaf litter tank some time back, the tank can run with fat, happy fishes for many months, subsisting only on the food the tank produces. I know several other hobbyists who have done this with similar results.

Assemblages of softer botanicals, which soften as they decompose, and leaves which "recruit" biofilms and fungi, form a secondary food source for many fishes and animals.

We know this. It's pretty much inevitable in our tanks, right?

So why not simply allow this to happen before adding your fishes?

Of course, the easy part is adding the botanicals and/or crustaceans, worms, etc. (if you choose to go the extra step) into your tank.

We more-or-less do this already, right?

The hard part is waiting longer to add fishes.

Wait a minimum of three weeks—and even up to a month or two if you can stand it, and you will have a surprisingly large population of micro and macro fauna upon which your fishes can forage between feedings.

Having a “pre-stocked” system helps reduce a considerable amount of stress for new inhabitants, particularly for wild fishes, or fishes that have reputations as “delicate” feeders.

And think about it. This is really a natural analog of sorts. Fishes that live in inundated forest floors (yeah, the igapo again!) return to these areas to "follow the food" once they flood.

It just takes a few weeks, really. You’ll see fungal growth. You'll see some breakdown of the botanicals brought on by bacterial action or the feeding habits of small crustaceans and fungi. If you "pre-stock", you might even see the emergence of a significant  population of copepods, amphipods, and other creatures crawling about, free from fishy predators, foraging on algae and detritus, and happily reproducing in your tank.

We kind of know this already, though- right?

This is really analogous to the tried-and-true practice of cultivating some turf algae on rocks either in or from outside your tank before adding herbivorous, grazing fishes, to give them some "grazing material." 

Radical patience yields impressive results.

I realize that it takes a certain patience- and a certain leap of faith-to do this. I’ve been doing it for a while and I can tell you it works.

If you like delicate or difficult-to-feed fishes, or even if you simply want to try something a bit different "just because", it’s a technique that could help you succeed where you might have failed in the past with some specimens.

The point of this practice is pretty simple. Embrassingly so, actually: To help develop—or I should say—to encourage the development and accumulation of some supplemental natural food sources in the system before they are quickly devastated by your fishes.

It's kind of the "refugium" concept yet again.

It's really a whole little concept which needs a lot more exploration. It's easy to do. It simply requires some planning, observation, execution...and a lot of patience. 

It’s perhaps a bit against the grain of popular practice, but I commend you for even considering the idea. You could play it out in all sorts of ways, even going so far as to "scape the tank with materials known to recruit more fungal growth, biofilms, algae, or other beneficial supplemental food sources.

Just thinking from a different angle.

At the very least, just considering different aspects of your fishes' "in tank experience" when creating and stocking a tank is a very cool thing. 

Besides, what’s the big rush, really?

You’ll develop a whole new appreciation for nature when you develop this form of "radical patience!" 

Until next time.

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


And Stay Wet.

Scott Fellman

Tannin Aquatics




June 12, 2019


"Slipping into the mainstream consciousness of the hobby..."

The idea of blackwater aquariums is nothing new. 

We at Tannin did not invent the concept. No one really did.

People love to point this out to me now and then, as if I have somehow "hijacked" the idea and presented it as our own creation...an absurdity that barely warrants a mention, of course. Blackwater aquariums have been executed for decades long before we ever emerged on the scene. Intrepid hobbyists have been experimenting with the idea of replicating blackwater conditions in their tanks for many years, utilizing natural materials like peat moss, catappa leaves, etc. 

We've expanded the "palette" a bit, of course. But that's hardly earth-shattering. While we appreciate the many accolades we've been receiving of late, it's important to point out that we've barely done anything in the grand scheme of things, really.

What we did do is execute on our goal to elevate the art of natural, blackwater aquariums from strange "side show" to more of an "accessible to all" sort of thing. We curated and aggregated the materials and information to accomplish these cool tanks much more easily. We've shared our interpretations, theories, observations, and practices.

No, we most definitely didn't "invent" this stuff.

Like any hobby endeavor, ours builds on the work that was done before, and seeks to improve, evolve, and expand upon it.

Blackwater conditions have been created for the purpose of breeding a wide variety of fishes, such as tetras, cichlids, and Rasbora since my Dad was a young hobbyist. Often, natural materials like peat moss were pressed into filters, media bags, etc for the purpose of "conditioning" the water (when used in conjunction with water of minimal to no carbonate hardness, like reverse osmosis/deionization) to create optimum spawning conditions.

It's only been a bit more recently that these materials were utilized to recreate what we call "functionally aesthetic" aquariums replicating in greater detail the wild blackwater habitats of the world. Tanks which not only looked like the wild habitats of our fishes- they functioned somewhat like them as well. And even more recently,  we as a community have really gotten into the weeds in an attempt to unravel the "why" and "how's" of these habitats and their ecology and function in the wild.

Okay, yeah, we know that. So, where is this going, Scott?

Well, here's the thing. 

Have you noticed, over the past few years, that the idea of blackwater tanks is no longer this weird side show thing at all? I mean, maybe it's because I'm a bit more attuned to the topic than most, but it seems as if there are more and more talented aquarists experimenting with and creating unique blackwater displays each month. The idea has begun slipping into the mainstream consciousness of the hobby as just another approach to aquariums, not some novelty executed for the sole intention of being "anti-establishment" somehow.

What's really interesting to me is that we, as a community, are not fooling ourselves, either. We're all learning together and making a concerted effort to share what we are doing. We realize that we are just scratching the surface of what is to be learned out there. We're digging beyond the B.S. and commercial hype of products and looking more towards Nature and the science, which I find fascinating. We're actually calling bullshit on ideas and practices- some long held- that "X" is THE way to do things in natural, blackwater aquariums- and others (like understanding detritus....hello!).

The fact that we are actually looking at blackwater tanks as more than just some cool aesthetic is incredible. We're looking at them as a means to "unlock" some of the ecological components of these specialized aquatic habitats and apply them to our closed-system aquariums to the benefit of the fishes we keep. We're not just throwing leaves into 8.4 pH tap water, seeing it turn a bit brown, and hailing our tank as a realistic replication of the Rio Negro anymore. We're realizing that there is much more to this thing.

Much more.

The thing I'm most proud of at Tannin is that we are not just "slinging leaves." We've made the conscious effort since inception to talk about the concepts and ideas behind the habitats we are looking to recreate in our aquariums. To create a forum and a sort of "clearing house" for ideas and discussions about this stuff.

As a  community- a hobby "movement"- we're doing way more. Going deeper. I personally have spent way more time reviewing scientific papers on arcane aspects of these wild habitats than I ever have looking at some guy's "tank of the month" in some contest, and I think more and more of you are doing the same. And we're getting more out of it, too. More interesting ideas to apply to our aquariums.

So, when someone does pull off an incredible tank, we're evaluating it not only on the look, but the function and the aquarium's "ecology" as well. THAT is super cool.

We are studying the natural habitats of our fishes in a different way. Not just checking out the cool look, but understanding the function, the ecology, the environmental challenges they face...Imagine what that type of awareness can do to inspire more people out of the hobby to reflect  on and admire these habitats and  think about protecting them for future generations to enjoy.

Yeah, it's getting pretty good.

And it will be getting better still. 

Keep doing what you're doing- and keep sharing your successes, failures, and everything in between. 

We'll have some new and (we think) VERY exciting stuff to share soon. We're excited.

Stay diligent. Stay inspired. Stay curious. Stay unique. Stay devoted...

And Stay Wet.


Scott Fellman

Tannin Aquatics 




June 11, 2019


Everything in good time...

In the aquarium world, success is as much about timing and patience as it is about just doing stuff the right way. You can learn technique, but you can't "buy your way" to long term success by grabbing the most expensive filter, pump, light, etc. It has to be applied correctly.

And even then, things need to be orchestrated and coordinated to move at the right pace...the right cadence.

ˈkādns/ noun-  The flow or rhythm of events, especially the pattern in which something is experienced.


As we all know, nothing lasts forever.

And it's especially true with our botanicals. From the minute you prepare a leaf or botanical for use in the aquarium, it begins to break down. The processes of hot water steeping, boiling, or soaking start to soften the tissues of the leaves or seed pods, and they begin the gradual, but irreversible process of breaking down, at a pace, or "cadence" which nature determines.



As they break down, more and more materials (tannins, humic substances, lignin, bound-up organic matter) begin leaching into the water column in your aquarium, influencing the water chemistry and overall environment. Some, like Catappa leaves, break down within weeks, needing replacement if you wish to maintain the "tint level" you've started to achieve in your aquarium.

Knowing when to replace them is sort of a subjective call, at least initially. Once you get used to working with them, you may be able to notice pH increased, TDS changes, or other environmental/water chem indicators which can clue you in that it's time to replace them.

On the other hand, many types of seed pods will last much longer periods of time than leaves in most aquariums, yet may not impart their tannins and other substances as quickly as say, leaves, simply because their very structure is different than the softer, thinner leaves. Many will hold their form for a very long period of time, yet may not be releasing quite as much tannins or humic substances as they were initially.

Again, it's sort of a judgement call.

Without the ability to measure the levels of the specific substances that botanical items are imparting into your tank (and, quite frankly, knowing just what they are!), it's really about "nuancing it", isn't it? Like so many other things in this hobby, you sort of have to take a "best guess", or go with your instincts. Hardly the precise, scientific, "boiler plate" advice some of us might like, but that's the reality of this kind of tank. It's not like, our example, a reef tank, where we have detailed chemical baselines for seawater parameters, and 32-component ICP-OES tests to establish baselines and measure deviations from them.

Nope. It's about nuance, observation, "feel"... finesse. 

Obviously, you need to obey all of the common best practices of aquarium management, in terms of nitrogen cycle management, nutrient export, etc. in a botanical-style blackwater aquarium. However, you have to also apply a healthy dose of the above-referenced "emotional elements" into your regimen as well. 

Remember, anything you add into an aquarium- wood, sand, botanicals, and of course- livestock- is part of the "bioload", and will impact the function and environment of your aquarium. It's about understanding a balance, a quantity, a "cadence" for adding stuff, so that the closed environment of your aquarium can assimilate the new materials, and the bacteria, fungi, and other organisms which serve to break them down can adjust.

Rapid, dramatic environmental shifts are never a good thing for any type of aquarium, and a system like we run, with lots of organic material present, is just as susceptible to insults from big moves as any other- perhaps even more. 

Again, the key here is that "cadence"- understanding that the material we add needs to be added-and replaced- on a pace that makes sense for your specific system. Those of us who have been maintaining these types of tanks for some time now really get this, and have a great "feel" for how our tanks run in this fashion.

Again, there is no "plug and play" formula to follow- only procedure. Only recommendations for how to approach things. We sound a bit like the proverbial "broken record"; however, like so many things in aquarium-keeping, our "best practices" are few, simple and need to be repeated until they simply become habit:

1) Prepare all botanicals prior to adding them to your aquarium. 

2) Add botanical materials slowly and gradually, assessing the impact on your aquarium environments and inhabitants.

3) Either remove botanical materials as they break down (if that's your aesthetic preference), or replace them when they reach a point where they are no longer providing the aesthetic and environmental conditions that you desire.

If you noticed, the first practice is simply logical. You need to employ it...if there were ever a "hard and fast rule in the botanical/blackwater game, this would be it. Number 2 is all about the cadence...the "secret", if you will, which sort of sets up everything else. BY observing and assessing, you'll get a real feel for how botanicals work in your aquarium.  And #3 is the real "finesse" part of the equation...the nuance, the subtle, yet noticeable adjustments and corrections we make to keep things moving along nominally- sort of like pruning in a planted tank, or weeding a garden...it's a process.

In fact, the entire experience of a blackwater, botanical-style aquarium boils down to a process and a pace that helps foster the gradual, yet inexorable "evolution" of the aquarium. And let there be no doubt- a botanical-style aquarium does "evolve" over time, regularly and steadily changing and progressing. As we've mentioned before, it might be the perfect expression of the Japanese concept of "wabi-sabi", popularized by Takashi Amano, which is the acceptance of transience and imperfection.

Nothing exemplifies this better than a botanical-style aquarium.

And it's all held together by you- the aquarist, applying as much emotion as you do process- all done in the proper time...at the right cadence. And enhanced by the passage of time.

Stay patient. Stay focused. Stay in touch. Stay attuned. Stay observant...

And Stay Wet.


Scott Fellman                        

Tannin Aquatics


June 10, 2019


More questions. More answers!

It's a lot of fun working with all of you people; sometimes, it actually feels like we have a real business! Now, approaching 4 years in business, it's more than appropriate to look back now and then, and to highlight some stuff that maybe we haven't discussed enough!

Even with me out there blabbing on incessantly almost every day, and with Tannin putting out email blasts, social media posts, etc, customers still have questions…Most are really good, important questions about stuff that, for one reason or another, we never got around to discussing. And some of them are things that you may have wondered, but haven’t gotten around to personally asking.

So, at the risk of looking a bit self-serving to my own company in my own blog on my own web page (Yeah, people have actually criticized me for promoting Tannin on our own page! Has the world gone completely mad?), I thought I’d share some of the more interesting “IFAQS” ("infrequently asked questions") that we’ve received over the past few years. I've saved the best for some strange purpose, like writing an "FAQ" thingy. So...These are real questions- and the answers are legit.

And sometimes intense, too! LOL. Like, you'd expect anything else?

Okay, so here goes:

What’s your FAX number? Our what?

Are you open on weekends? We are open 24/7, 365…online.  We do have to sleep, of course...However, with a global community of customers, we try to be more available. It’s not uncommon to receive a reply to you email some weekend at 5:00AM Pacific Time. I'm always with my damn phone, so jumping in on a conversation on Facebook or Instagram is always part of the game!

Do you have botanicals and "stuff" that aren’t on your website? Well, with all of the botanical items we've experimented with and offered for sale over the years, there are always a few "one-offs" out there, or items that we have a scant few of, which weren't available in large enough quantities to offer regularly, or which proved unpopular, too hard to ship, etc. Yeah, we have played with a lot of stuff over the years, so if you want something that you don’t see on the site, there is always a chance we have some "mystery stuff" floating around. Ask for something in your next "Enigma Pack", and if we have anything cool, we'll include it.

Do you guys sell fish? Well, not at the moment. We did try for a while last year, but it was really outside of our core mission and fraught with logistics challenges, so wisely, we stopped! Of course, it's always a future possibility that we'll do it again...Well, maybe.

Do you sell blackwater? (asked by a guy who lives in Wisconsin. We are in Los Angeles, remember) You mean, like through the internet? Ship blackwater to you? I love my fellow hobbyists. But... Really?

Can I use Cariniana Pods with my fishes? Priceless. And true (November, 2016). This is when you tell yourself, "I just need to do better...I'm not doing something right..."

Do you miss owning a coral livestock business? Oh sure, as much as I miss acne, migraine headaches, doing my taxes, etc. No, seriously, it was amazing, fascinating, challenging, fun. But it was a different sort of market and a different end of the business. And livestock vendors have a lot more to contend with when shipping live animals across the country-or the world. It requires a lot of dedication, skill, and fortitude- like any other part of business- but it's a bit different. I love what  we're doing here at Tannin- fostering a movement in the hobby!

Off the deep end, for sure..one of our 30 foot-long coral grow-out raceways, "back in the day."

"You guys should offer WYSIWYG Leaves." That wasn’t a question. (but a true statement from 2015!)...Now, I'm just crazy enough to do that. Really. Can you imagine photographing 300 different leaves? If anyone would do something that insane, it would be me. But, who would buy them? That's the more important question! 

"Do you offer shipping to my country? I don't see it listed." We ship all over the world, as indicated in our website, but we haven't shipped everywhere yet! Some nations have very strict laws governing bringing plant materials in, and others levy ridiculously high taxes on just about any imported items, so we can certainly TRY to ship you your country in it's not yet on your list..It's just that we cannot guarantee it will be trouble-free. Some countries are picky about imported botanical materials, and may give you some hassles. And you are responsible for any taxes or other fees that your government charges on your end. Yay, fun.  And of course, the add-on question usually is "Your shipping to my country is $40. That's too much. Can you do better? The short answer is that when you pay $40, I'm likely paying like $45...So, at this point, there's not much we can do to really get costs down. It's just an annoying "thing" we have to deal with. 

There's a guy on E-Bay that sells leaves for $3.00 less than you do. Will you price match? No. If you want to know why, visit our website and social media feeds, then visit his. Enough said.

How long can does it take to ship my order? Now, we typically try to ship all orders within 4 days of the date they're received. And to be honest, we're obsessive about getting your order out within a day (weekdays). However, sometimes, because of incoming shipments, heavy demand, or the fact that every single botanical item is selected and packed specifically for your order, there can be delays. We generally try to inform you if there are. Honestly, we'll keep doing our best to get your orders out as quickly as possible!

Do you substitute if you don't have something? Typically, if we're out of something in your order, we'll  contact you to see if you want us to substitute with a botanical of similar "configuration" and value. Our first choice is to wait until we receive a re-supply, but this can often hold up an order longer than we'd all like (the joys of a global supply chain...). We will generally inform you if a substitution needs to be made within an order. If we don't have an item you order, we'll definitely contact you to discuss options if the delay is more than few days...

"Do you have "Designer" Wood Pieces?" (asked March 2017) We’re a bit low on Calvin Klein at the moment, but we have some lovely Prada Mopani Wood, and a few Michael Kors Spider Wood pieces... This must have been asked by a (former) reefer.."designer", huh? Well, to be honest, there are all sorts of cool wood varieties out there, and we certainly would like to procure more of them, but the irony we've found is that the more "crazy" wood pieces you have (and that typically is code for "expensive"), the less you see of it.  That one cool 24-inch piece of wood from the Himalyan Mahalangur HImal region probably cost $80 just to ship to us, so we'd have to charge quite a bit for the piece just to cover this cost, right?

And the longer it sits in our facility. Wood is one of those things that I agree  can be tricky to purchase online. We try to stick to a few varieties that we know sell well at a fair price. Stuff you ask for.  And we hand-select each piece, so you know you'll get something that we'd want in our own tanks!

Now, trust me, we try hard to procure new stuff. We even get contacted by some new wood vendors out there...However, some of them are, in my opinion, incredibly "flaky!"They'll often contact us, romance us, send us a few samples at cost, and then promptly...disappear, never to be seen or heard from again when we want to order. I had one would-be supplier stall me repeatedly and then simply vanish, because they were "waiting to set up an LLC and needed to hear back from their lawyer and accountant..." I was like, "YOU'RE SELLING FREAKING COLLECTED DRIFTWOOD! NOT AIRPLANE PARTS OR HEART VALVES!" Urgghh!  

I mean, it would be cool to find more cool wood varieties (it's in our tagline, right?) , and we'll keep searching, but the market is kind of narrow for us to go really big on some really obscure stuff. It's kind of "when we stumble upon something cool..." We will continue to seek out and offer some new stuff, but the reality is that if YOU don't want to buy it, it's probably not something we'll be buying either!  Oh, and seriously, remove the term “designer” wood pieces out of your head. Please. Or "designer corals", for that matter Who actually designs them?

Rant over. Don't get me started.

"Do I need to prepare these botanicals before I add them to my aquarium?" This one kills me, to be honest. We have a dedicated preparation page, lots of blogs on the topic, etc., all over our web site, so yeah...

Do you wear long pants to work sometimes? Do I WHAT?

I live in the nation of______. When I received the box of botanicals, the customs guys asked for ________ euro (or whatever local currency you use) to get the package! That's too much!"  I feel your pain. Really. Hate it. Shipping and taxes and stuff really sucks. But not much we can do about it, really. It bothers us as much as it bothers you...However, we can't be responsible for the taxes and fees that your local government levies on imported items. We advise that repeatedly in our "Shipping and Handling" section. Please read this section before you order!

How do I find out when you have sales? Sign up for our newsletter on our home page, and follow us on Facebook and Instagram! It will generally be a great tip-off for when we have those famous sales and events!

Can Scott come out and speak at my club event? Whew...Do you REALLY want that? I'm a total risk... I'm likely to go off into a total tangent... If you dare, however, shoot me an email and we can set up a date!

Do you REALLY want this guy speaking to your club?

Do you do "live" sales? Urrghhh. I think we all have a root canal scheduled that day. Or perhaps we need to go to the DMV…Or call the cable company..Or have our taxes done…or…Maybe one day we'll try a "Facebook Live" sale or something, but I'm old and set in my ways, and....yeah.

Does Tannin sponsor clubs? Sure. Shoot us an email and we can see what you need. We've been involved for years in the aquarium club “scene”, and are huge supporters of clubs! They're so important to the hobby!

Can you get me “_______ ?” I didn’t see it on your web site. We will sure try to source it for you if we can. Just hit us up, and we’ll do our best! Can't promise results, but it's often fun to try!

Do you still enjoy keeping fish tanks?  Obsessively!

Can you guys help me scheme out a botanical/blackwater aquarium? Sure, we can. Call us and we can discuss your idea and figure out what you need! 

I haven't heard much about the "Igapo Challenge."  Is that still happening, or what? Absolutely! There are a lot of moving parts to planning a legit, transparent, "open-source" contest like this (more than I even figured before I shot my mouth off about wanting to do it!), and we want to get it right. In addition to figuring out the format, we need to make the entry process easy, track stuff, and continue to line up some killer prizes! In the context of our daily work of running Tannin, by necessity, it has to take a back seat to customer care and some of the changes we've been implementing, so it's going to take a bit longer to get it on...Rest assured, we are doing this. Likely early in the Fall. And it will be cool! I promise an update soon!

"When you guys started out and came on with the "botanical thing" , it ticked off some people? You know, you didn't invent this stuff! Other people sold leaves for years before Tannin arrived on the scene! And more people are going to come and do what you're doing-and cheaper!" (from a "not-so-nice" email, September 2016)  And your point? First off, when and where did we claim to "invent this stuff?" Please do show me. What we have done is to curate and hopefully "elevate" the art of creating natural, blackwater/botanical-style aquariums and make the materials to accomplish this more readily available, backed up with lots of good free information, customer support, and a talented global community of people interested in these types of aquariums.

Business isn't all fun and games. Competition is real and intense. And if a few people who were "selling leaves" before we arrived are "mad" that we're in business, should I care? And if more people want to jump in, that's capitalism. They better be innovative, not just "adding on" to this sector... And of course, we don't sit still. We have to keep upping our game continuously. It's part of the process. There are always entrenched businesses and competition- in any endeavor. And do you think THEY "care" about us? Doubtful. Was anyone hanging out the "welcome mat" for us when we arrived? Don't think so.

Did they identify, shape, and support a target market for their business? Create a "brand?" Provide real customer service? Were they sending free stuff to clubs for months, donating to charities, fostering a community, writing a daily blog that few people initially read- like we did..or were they just selling stuff on eBay? Hmm.  Brr...a cold and mean assessment, I know- but hey, that's business. Any serious aquatics (or other) business owner will tell you the same thing. It's not about being arrogant or whatever. It's reality. Not everyone gets it. You have to Innovate, iterate, improve- or wither away and die...or simply be obscure. They have to. We have to. It's hard. But, it's that simple. And who cares? When you choose to do anything for a living, you need to give it 150%. Every day. No big secret here.

Did you plan on coming out with shirts and more logo wear?  Yes, I promise! We'll have some new stuff coming up. The key has been to find stuff that fits the "vibe", doesn't "cheapen" the brand, and that you actually want to wear! Stay tuned for more!

Do I have to sign for my package when it arrives? Not typically for domestic shipments. We usually do not ship packages with a signature required unless the situation dictates it. International shipments have different requirements, however, and DHL will typically contact you regarding delivery...so please include that phone number! 

How do you think of new stuff to write every day? It's not easy, believe me...but not that hard, either...It's weird. I just relax, close my eyes, and write. Much respect for people like Rachel O'Leary ,  Joey ("The King of DIY"), Dustin of "Dustin's Fishtanks", and others- all who do You Tube videos. THAT requires some serious talent! I admire all of these people for their dedication, hard work, and inspiration that they provide to the hobby. They do it right! 

Does the “____________” pod or leaf look like it does in your picture? We think so. Maybe better. We strive for accuracy.

Do you have a favorite botanical? Nah. Really do like ‘em all.

What’s the biggest mistake you made? Not getting into this business decades ago! It's so fun to work with you people! All the "testosterone" of the business part aside, it's a great thing and a wonderful group of people that we are so fortunate to have as customers, fans, and friends.

Okay, I’ve went on long enough… Some of these were a bit intense, I know. But hey, you asked! There are many more questions we receive, of course, because customers keep asking…And we will keep answering. Wouldn’t have it any other way.

Until next time...Have a good one!

Stay engaged. Stay interested. Stay inquisitive. Stay diligent. Stay curious.

And Stay Wet.

Scott Fellman
Tannin Aquatics 

June 09, 2019


Contemplating the stereotype of "the scavenger..."

Oaky, I freely admit that I can be easily annoyed at times. And it's kind of funny what kind of stuff discussed in our hobby can set me off. It typically happens when I am scouring some fish keeping forums ( as is part of my daily ritual) and come across some sort of discussion that demonstrates the strange indifferences we tend to demonstrate towards aquatic animals at times.

I came a cross a few threads in which new aquarists were asking the age-old questions, "What are the best fishes to eat algae and keep my tank clean?" and "What's a good cleanup crew for my community tank?"

Innocent enough, right? I mean, not really a big deal, huh?


This is a question that, in my ripe old age, makes me a little bit perturbed, actually. In fact, it kind of gets me riled up a bit. Yeah. I mean, there should be a lot of other things about this hobby that get under my skin, but this one sort of does it for some reason. I mean, here we are in the 21st century, with every technological advantage possible- devices, techniques, and methodologies designed to maintain pristine water quality and beautiful aquariums, and we're still sort of "deferring" the maintenance duties to fishes and other animals...? 

(Peckolitia compta L134- Just an "algae eater?" I should think not!)


Makes you think a bit. 

I think we lean a bit too much on various animals to perform some of the roles that we need to have a better grasp of...This is in stark contrast to setting up an aquarium which accommodates the specific needs of certain fishes or animals. 

We'll get back to that later on.

The irony is that we have given these animals “duties” in our aquariums  when, in reality, they are simply behaving as they have in the wild for eons. We’re assigning a “role” to their existence based on our needs…Weird, huh? Or kind of "arrogantly presumptive", maybe?

Okay, I can see there will be a few who will say, "Fellman, you're being sort of hypocritical in your arguments here..." Well, perhaps, but I'd love to see us look at this from a slightly different perspective...

There are a lot of animals which are selected by us hobbyists for this "role" in aquariums  Many are of debatable value in terms of consuming things that we don’t want in our tanks. Others are without debate perfectly suited for what we want them to do. Some arrive in our tanks from plants or driftwood from other aquariums as sort of "hitchhikers", in a decidedly natural manner, without our intervention. Others are deliberately added to our aquariums as part of what we think are necessary "cleanup crews." The composition of these “cleanup crews” is a well-discussed topic…We’ve dutifully assembled rosters of animals that we feel will do the job at removing the stuff we don’t want in our tanks, like algae, uneaten food, and "detritus." (don't start me on that shit, please.)

(An "Algae Eater!" Don't get me started with this one....)

Everyone has their opinions of what animals are best, and how many you should have. “X” number of this-or-that per gallon/liter, or some such nonsense. I think it’s absurd. I mean, really, who has done studies on how much algae an individual snail will consume in nature? Yet, we as vendors and hobbyists come up with exotic formulae…based on…what? And how much algae can support “X” number of snails in an aquarium, and for how long? At some point, food supplies will be exhausted with a large population of these animals in residence.

Then what?

I mean, if I were a snail, I wouldn’t want to share my 30 gallon tank with 15 other hungry neighbors. I’d just want the space for myself, or maybe a few friends of the opposite sex. More food, more fun…If you can call a snail’s life “fun”, that is.

Now, yeah, it is a bit more of an "art" than a "science"- and no one really has the perfect answer. And sure, I sell fish stuff for a living, so who am I to make such assertions and proffer my criticisms? Well, I'm just another hobbyist asking questions. We've discussed this before, but it comes up a lot in discussions.

This is a pretty common thing in the reef aquarium world, where you see vendors selling packages of snail, crabs, shrimp, and starfishes as "cleanup crews." At first it seems innocent, but beneath the shiny veneer, it's actually kind of dark and sad: We consider these animals a sort of "disposable" and "temporary" commodity- using them for their "cleaning services" until we have no more algae or detritus or uneaten food or whatever in our tanks. Then, if they live, great. IF they perish- well, we can always get more, right?


Yep, I see this in the reef aquarium world all the time:  Recommendations for large number of animals like Brittle Stars and such to handle "detritus"...One of the big problems I have with some of the more “traditional” detritivorous “cleanup crew” members is that they are often animals that consume detritus as a part of their diet, and make a greater part of their diet the micro and/or macrofauna that you are so carefully trying to cultivate for your biodiveristy and nutrient export processes.


To make matters worse, hobbyists are often advised to keep large numbers of these animals in their reef aquairums, which assures that not only will they decimate your beneficial infauna, but they’ll probably slowly starve to death as a result of their own "efficiency." I mean, Brittle stars and some of the snails we use are good at getting at detritus, but if part of what they are consuming are animals that you want in your system, particularly in your sandbed- then its a considerable tradeoff, isn’t it?

It's no different in freshwater, really. The "cast of characters" is slightly different, but that's it. The "mission" we've assigned these animals is the same: It's all about eliminating algae and "detritus" in what we consider a "natural" way.

Let’s talk about the apparent dreaded "enemy" of clean tanks…detritus!

Detritus (or “detrus”, as one of my local reefer friends annoyingly refers to it with his typical malapropisms) is a great scientific-sounding “catch all” term for “stuff” that accumulates in your rock and sand- mainly, partially decomposed or uneaten food,  mucous, fish waste, etc. The working definition is “non-living” organic material; or more properly, organic-rich particulate material. Although continuously broken down by microorganisms in a healthy, established aquarium, some of the materials are not completely consumed by these lower organisms, and can be at least initially “worked over” by detritivorous animals and fishes.

Is it bad? Well, yes and no.

I mean, if the materials in the detritus continue to break down, they can create less hygienic conditions in a closed system, or provide “fuel” for nuisance algae growth. However, if you embrace it and view it as a supplemental food source for your animals, which it is- it doesn’t seem all that bad, huh? When we've talked about deep leaf litter beds as a possible means for cultivating supplemental food for our fishes, and have experimented with "inoculating" these beds with animal like worms and such, it's not so scary!

Fungal and bacterial growths act on it, and also serve as supplemental food sources for many fishes in our aquariums...Perhaps detritus is "fuel" for kickstarting our closed ecosystems? 

Okay...that's it for now for detritus.

I mean, based on numerous field studies I've read, that it's a pretty safe bet that many fishes of all types will consume this stuff as part of their diet. Assigning a fish to the exclusive role of "detritus cleaner" is a bit, well...arrogant on our part. Like, they're supposed to ignore all of the good stuff you feed the other fishes and simply subsist on detritus alone?  This is, I suppose, where I admit that my argument gets a bit weaker...

But what about algae..and those snails we "employ" to take it out. We like to add snails, right? At least they're cool for a while, until they multiply. And lot of these snails will reproduce along the way, sometimes creating large populations. So what do we do? We purchase "Assassin Snails" to take 'em out.

So...We're using another animal in a limited role to solve a "problem" that we sort of created in the first place by using a different animal for a limited role...


(The "Assassin", Clea helena. Pic by Snek01, used under CC BY-SA 3.0)

So when I see people asking about fishes as designated "algae eaters", I tend to get that familiar uncomfortable feeling. Yeah, a lot of fishes love eating algae, but I think we need to look at them for what they are: Cool little fishes (Otocinculus cats come to mind) that are interesting and enjoyable in their own right, which happen to consume algae as part of their diet. Not animals that we should stock in our tanks strictly for the purpose of taking it all out.

Fortunately, many of us have sort of "grown out" of this "stereotyping" thing for some fishes...I mean, when was the last time a serious hobbyist purchased a Plecostomus strictly as an "algae eater for their community aquarium?" Or a Corydoras as a "scavenger?"  On the other hand, it's not totally uncommon to see this thinking perpetuated in the general hobby arena...


(Corydoras sp. "CW008"- The perfect "scavenger?" I should think not! )

Try running that idea by one of the many hardcore Loricariid fanciers out there, who collect, keep, and breed these amazing fishes regularly! I don't think it will go over all that well...Your time would be better spent learning how closed aquatic ecosystems work, and how algae appear in significant amounts based on a set of characteristics which arise to facilitate their growth.

So, really, relegating these fascinating fishes to "scavengers" who are in our tanks for the sole purpose of keeping our tanks clean is a little "out there", really In fact, it's unthinkable to lots of dedicated hobbyists! People set up entire fish rooms to keep these fishes in optimum environments. Entire collections are comprised of many beautiful places and corys.

However, I suppose it's understandable that we make up a "role" for them.  It's kind of our own fault.


We feel good about using "natural controls" for problems, and I think it's great...but we also tend to look at the fact that it's really OUR responsibility to keep the tank clean, right? We can enlist the help of animals who are known to consume algae and uneaten food...but I personally don't think we should make the only reason for any fish's inclusion in our aquarium one of a "cleanup crew" member. 

Back to snails again.. (this is like a tennis match, huh?)

If you do incorporate snails into your aquariums for this purpose-and I think you should...I say, start really small, adding just a scant few of these animals into your system at a time. Just because “experts” or vendors recommend “X” number per gallon doesn’t mean that’s an appropriate stocking level. Remember, these animals need to eat, and if they exhaust their food supply, they will perish. They'll multiply if they are happy, and if the food resources are sufficient...so why not start off with just a few?

Really. I mean, if the thought of introducing new algae-covered rocks and wood into your tank just to feed your large population of snails after they've exhausted the available food supply doesn’t appeal to you, then stock with just a few to start and see how they do.

Or just get really good at taking the stuff out yourself.

OR...learn to appreciate this stuff.


You can always embrace biofilms, algae, and fungal growths for what they are: Nature's most efficient processors of biological material. Not quite as easy or sexy as buying a dozen Otos or 20 snails, but perhaps far better suited for the "role." (okay, I can see some smartassreader railing on me as a hypocrite for postulating that we "assign" nutrient export duties to fungi and bacteria...)

Let's make the effort to continue to teach new hobbyists the value of proper husbandry; the basic skills required to identify problems, concerns, and ongoing maintenance requirements in our aquariums. Understanding how attempting to re-create more natural-functioning environments and their ability to utilize nutrients and food inputs is a fascinating endeavor, and I think our botanical-style aquariums are a good place to start!

Water changes, algae scraping, feeding carefully, etc., all are more important than ever...We can't solely rely on a piece of equipment or an animal to do our jobs for us...

So sure- it's okay to incorporate these animals into your stocking plan, but be reasonable and humane in your assumptions. Treat them like the treasured living creatures that they are. 

Play an active role in the process of maintaining your tanks. Don't "outsource" all of it to the fishes.

It's our responsibility to take the initiative and to perfect these skills...It's NOT our fishes' "job"- and that's for the benefit of all!

Stay compassionate. Stay thoughtful. Stay curious. Stay empathetic. Stay diligent. Stay engaged...

And Stay Wet!


Scott Fellman

Tannin Aquatics

June 08, 2019


Return to the igapo...

If you think about it, the flooded forest floors of Amazonia are some of the most interesting and unique habitats in the world. We can't seem to stay away from them as one of the ultimate models for biotope diversity and sheer fascination!

These bodies of water are "seasonally inundated" by the significant rainfall common ottos region; some of these forests may be submerged for almost half a year...that's a LOT of water! Like, 3%-4% of the water in the Amazon Basin at any given time...And these are precious, diverse natural treasures, so replicating one in the home aquarium is another way to learn and teach more about them, isn't it?


Igapo forests have a pretty significant amount of trees; one study found that over 30 species of trees are found in these areas, creating coverage of something on the order of 30%, and are known to have soils that are acidic in nature, yet low in nutrient content (because they don't receive a seasonal influx of nutrients like regions called "varzea", which are flooded by sediment-laden "whitewater" rivers). The water depth can vary from as little as 6-8 inches ( 15.24cm- 20.32cm), to almost 20 feet (6.96m)!  And of course, they have a lot of tannin and humic substances in them from all of the soil and plant materials.

Igapo remain surprisingly "nutrient poor" by ecological standards, because the nutrient-rich alluvial sediments from the Andes, carried by whitewater rivers, which are deposited into the varzea forests annually, don't find their way into these habitats. 

Another interesting thing about Amazonian streams and flooded forest areas in general is that there is no significant "in situ" (in place) primary production, and that the fish populations that reside in them depend on what is known as "allochthonous input" (material that is imported into an ecosystem from outside of it) from materials like seed pods, fruits, blossoms, leaves, and dead wood from the surrounding forest.

This is why leaf litter beds are so important in blackwater, as they serve as sort of "aggregators" of terrestrial material, and foster decay and biological processes which support what aquatic ecologists call  "food webs." Most of the aquatic life forms which reside in these waters are aggregated in submerged litter.

These inundated forest floors are fascinating subjects for aquarium replication! As we mentioned before, the soils in these forests are typically acidic and sandy. The tributaries that flood them are often covered with a whitish, fine-grained sand, which is commonly found in this habitat after the inundation. So, from an aesthetic and functional standpoint, many of the aquarium-specific sands that we play with in the hobby are perfect for this type of simulation.

In a comparative study of Amazonian fish diversity and density conducted by Henderson and Crampton in 1994, in nutrient poor blackwater igapó at the blackwater sites had low turbidity, a very low conductivity, and a pH of 5.3-6.0. A more recent study I stumbled upon indicated a pH range of 3.4-5.5, so it really depends on the specific locale, the length of time that the forest has been inundated, and the density and quantity of the leaves and other plant materials which accumulate on the substrate. 

In these Igapo habitats, the dominant species of terrestrial grass when in the dry phase is Lagenocarpus pulchra (Google that one!). There are other plants in the family Cyperacea which includes some riparian species available in North America and Europe...I mean, a terrestrial plant which survives periods of inundation? Who's up for THAT experiment?

The idea of a submerged grassy forest floor with leaf litter is enough to send my creativity into overdrive!

Can you envision creating THIS in your tank?

The sites in the study held high-diversity fish communities with many species  yielding 68 species. Each section of this habitat has some characteristics which shape the population composition and density, and it is worth noting when thinking about stocking our aquariums, doesn't it?


I think it does!

Thanks as always to our friends David Sobry, Mike Tuccinardi, and Tai Strietman for their compelling and inspiring photography! 

Explore these inundated forests. Help unlock their secrets, their function...Learn about the challenges they face, and the unique interdependencies among the species which reside there...

Create an igapo in your own home aquarium! It might just change the way you look at "natural" aquariums!

Stay inspired. Stay excited. Stay curious. Stay creative. Stay persistent...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

June 07, 2019


Making the cut: "Editing" and the botanical-style aquarium...

As hobbyists, we love "tweaking", modifying, and changing stuff. Sometimes, we do this on a big-scale (like, tearing down our aquascape and starting over). Other times, it's about making smaller, incremental changes to our tanks.

Incremental steps are important in just about any aquarium; however, they're almost a given with the botanical-style aquariums we love and work with. Like any aquarium, it's a given that we won't reach the "final" version (is there such a thing, lol?) of our botanical-style aquarium for some time...if ever.

I can't tell you how many times Ive started out with one idea, and ended up with something quite different after a relatively brief period of time.

To me, it's best accomplished gradually..It's a constant "evolution" of sorts. A series of slow, steady adjustments. A process which keeps us in control of the situation, and to a certain extent, mimics what occurs in nature, right?

Yeah. Think about it for just a second.

In nature, things don't ever really reach an "end"- they just keep changing...It may occur over eons, but it happens. Changes in climate, water flow, erosion; an influx of materials into the aquatic environment all play a role in this. 

When we set out and add a bunch of leaves and botanicals to our aquarium, doesn't this sort of parallel what happens in nature to a certain degree?

It sure does! 

I mean, one could draw parallels between pretty much everything that we do with our aquaria and what happens in nature; however, I think that the botanical-style aquarium lends itself to replicating some aspects of nature better than many other types of systems we play with as fish geeks! I mean, the very process of adding and removing botanical materials to our aquariums is a near perfect replication of what happens in these environments in nature!

Occasionally, you'll end up doing "addition by subtraction" in a botanical-style blackwater aquarium! Like, making a serious "edit" to move forward.

This happens to me all the time.

I'll start out with lofty plans, select a bunch of botanicals and wood and such, and set up a nice 'scape. I'll run it in for a few weeks and realize that, for whatever reason, it wasn't "hitting" on the points that I wanted...So I'd start removing stuff that I felt pulled the tank away from the original vision I had for it. 

A great example of this was the nano aquarium I set up in my office earlier in the year.. I had a vision for this aquarium when I started- to be the most "leaf-centric" version of an Amazonian igarape habitat I've ever done.

Was envisioning shallow water, tangled twigs a well-distributed  layer of small Texas Live Oak Leaves, and a scattering of small botanicals. I'd incorporate some wood to evoke the feeling of a "root ball" that was suddenly exposed to the  inundation of water. And just one species of fish- the cute little Paracheirodon simulans ("Green Neon Tetra"). I even threw in a cutting of "Cat Palm" that I had rooted in water for several months for that extra touch...

Simple, easy-to-execute, and a fairly good representation of the habitat I was interested in.



Of course, it was a good "start"...It even received a lot of encouragement and praise from our Instagram and Facebook followers (not that those things are the ultimate "metric" of "good", but...). It was a tiny tank, but I found a lot of pleasure in it.

For a while, anyways.

Something about it just wasn't "right" about it to me.

You know that feeling, right?

I had to do some hard thinking about this. I looked at my pictures of the wild habitat by Mike Tuccinardi, David Sobry, and others, and thought about the "dream" tank I was thinking about for so long: Just a layer of leaves and a small scattering of twigs.

Nothing else.

And of course, you know what I did next, right?

Out came the wood. Back to a vase of water went the little palm. Out went the small Cariniana Pods and such.

So what I had was the tank I had yearned for all these years: Shallow, tinted water, a very thin layer of sand, and a cover of leaves and just a few small oak twigs.

Nothing else.  

Now, I admit that I hated the efficient, but butt-ugly Eheim surface film extractor thingy on the right side, but it did work great. I thought about pulling it in favor of just a well-placed airstone for surface agitation/film removal. Or even no ayirstone. The auto top off sensor on the left, near the filter inflow/outflow pipes was a bit annoying, but kind of unavoidable (And it makes life easier, too!). That shallow tank with it's wide open top evaporated a significant amount of water daily.

Now, as you know by now, I absolutely hate visible hardware in a scape, so next time I do this on a large scale, I'll use a reef-ready tank with integrated overflows and a sump! 

So, yeah. Just leaves and a handful of twigs. And really tinted water. That's a "future edit!"

I'm SOOO doing that tank. I can imagine a school of like 200 Neons or Cardinals over nothing but leaf litter in a larger aquarium. People will be like, "Why?" 

And then I'll be able to explain. To share the details on the wild habitat which inspired it. I could never do that with a "high concept" diorama scape, which has in much in common with a natural aquatic habitat as do cut flowers in a vase, IMHO.

Shit, I'm getting nasty again. Time to wrap this up.

I realized that this was not everyone's aesthetic "dream tank"; definitely not the aquascaping world's vision of "ground-breaking" work- but it was exactly what I envisioned. Minimalistic on initial consideration and observation, but when you really take the time to examine it, this "no-scape" is remarkably dynamic and engrossing. And functionally amazing. During my months-long experiment, I ran this tank with NO EXTERNAL FOOD INPUTS and the fish were as fat an happy as they day they were added... Yeah, leaf litter, biofilm and microorganisms do wonders, huh?

It is something that proved to be oddly compelling to me. I can imagine it on a larger scale...I think it could be mind-blowing if executed well.

This tank was a great example of a good edit... A perfect example of "addition by subtraction", if you ask me. The 'scape ended up being exactly what I wanted- by taking stuff out!

So...The simple message here?

"Edits" are okay. Don't be afraid to "edit" from time to time. It's part of the evolution of your aquarium- even if it means that you're taking out a lot of what might have been "safe" and more openly accepted by others. Even if it means making what seems like a radical change to get to where you want to go.

Yes, less can be more. Really.

"Editing" is important.

Stay creative. Stay focused. Stay bold. Stay fascinated. Stay diligent. Stay relentless...

And Stay Wet.


Scott Fellman

Tannin Aquatics

June 06, 2019


Some thoughts on "aquatic cross training..."

It’s no secret that many of us have our "roots", so to speak, in saltwater.

My recent hobby/industry background had me firmly planted on the "high side" of the "specific gravity line" - being both an avid reef hobbyist/lecturer, and former co-owner of one of the reef aquarium worlds' most admired and respected coral propagation facilities/coral vendors. And during that time, I always admired and kept freshwater aquariums, too. And my story isn't all that unique.

Whether it was a quick stint with a clownfish in a 10-gallon tank 15 years ago, or full-on reef tank not all that long ago, saltwater is not a strange “media” to most of us in the general aquarium community. However, for some reason, in recent years, there was this “stigma” associated with even liking saltwater in the freshwater world- let alone admitting that you had a saltwater tank. It was like it was a real risky proposition for your “cred” as a planted tank lover, cichlid breeder, or whatever. And blackwater, botanical-style? WTF is THAT?

"You're crossing over to the 'Dark Side' now." is a common tease you'll hear from your hardcore FW friends if you admit to setting up- or even explore- the possibility of a reef tank. And you wouldn't believe the reaction I received from my reef-keeping friends when they heard I sold my interest in the coral propagation facility and started Tannin Aquatics: "Are you kidding me- like, brown beginner's fishes... Really?

It was as if they viewed this as some sort of "downgrade" or something.

As if there is such a difference in the "culture" or overall attitudes between reefers and say, freshwater aquascaping or biotope-aquarium-loving fanatics, I have yet to see a significant one. Trust me, I'm in both worlds, and factions among each side see the other as "snobby" and "elitist"; it's kind of funny!  And it works both ways, trust me. As recently as a couple of years ago, I remember getting gently teased by my reefer friends when I professed my love for freshwater. And I also remember attendees at my talks around the country coming up afterwards and sheepishly “confessing” that they had a soft spot for freshwater, too! 

It's funny how times change.

With the advent of so-called “high-end” planted freshwater planted tanks, with their associated concept, CO2 injection, reactors, lighting, and such,  and with the unabashedly unique idea of botanical-style aquairums- there has been a palpable shift in the reef aquarium hobby’s collective mindset about the “cool factor” of freshwater tanks! Suddenly, it’s in "vogue" to not just talk about, but to aspire to- or even own, a freshwater system- particularly one of the “high tech" planted systems, which are the freshwater equivalent of a reef system…I can’t help but think that the gadgetry/systematic approach and ‘exclusivity” factor of these “high end” FW systems is part of the “new appeal.”

And of course, there are more and more super experienced planted tank enthusiasts and fish breeders who want to set up a reef tank to "dabble" with corals. They're already familiar with husbandry, water quality management, and systems design, so it's simply a matter of working with a different "media", much like an artist might work with oil paint and acrylic. The nitrogen cycle, temperature management, filter media, and 80% of the system designs/equipment are the same in both freshwater and saltwater.

There are many, many compelling reasons why a freshwater hobbyist SHOULD own a saltwater tank (reef, especially). I’m throwing out a few that come to mind just to spur some further discussion and provoke you to try one if you‘ve been on the fence a bit. Here they are- in no particular order:

*Saltwater aquariums offer a totally different aesthetic experience- Yeah, imagine a tank that you light with customized blends of color, regardless of the form factor of light that you use…simply because corals require it. No yellow daylight look here, baby. And the vibrant pinks, greens, yellows, and blues, of corals and marine fishes offer an entirely different palette to work with.

*Saltwater systems embrace biological and chemical principles that will better help you understand things like nutrient cycling, trace element uptake, etc.- If you like dosing stuff into your planted tank, you’ll love a well-managed reef system! You can explore the effects of supplementation on coral growth, and have real time results. Corals seem to respond even more quickly than plants to changes in their environment, so they can really “keep you on your toes!”


*Saltwater systems challenge you in different ways than a freshwater aquarium- In a freshwater system, there is a lot less emphasis on gadgetry, plumbing, and such. Rather, your greatest energy is expended on actually managing and running the tank itself. In "reef culture", gadgetry is more in the forefront, I'll give you that. Reefers love protein skimmers, reactors, high-tech lighting systems, and electronic controllers. It doesn't have to be all about gadgets, however. As an experienced freshwater enthusiast, you bring a lot of tank management and  observation skills to the table are perfectly applicable to reef keeping.

If you can handle a 40-tank fish room, you can handle a 125-gallon reef aquarium, no sweat. If you could manage a blackwater, botanical-style aquarium, you've got the upper hand. The philosophies of care of these diverse aquatic systems are interchangeable, really. You will learn to recognize growth patterns of the corals that you keep, how the fishes that you select affect the corals, etc. Learning the relationships between corals fishes, and other reef organisms will make you a better, more alert reefer, and those skills are already present in every hardcore freshwater aquarist!

*Saltwater systems offer you a chance to inject the “soul" of freshwater aquarium keeping into a culture that needs some- Yeah, there is an “art” to the saltwater hobby…lost somewhere in a cacophony of LED lights, electronic controllers, Facebook frag auctions, photoshopped coral pics, debates over “LE” coral names, etc., etc. so prevalent right now. A freshwater aquarist is way more attuned to the “core” experience of aquarium keeping, and the culture in freshwater is far more "evolved", offering you the opportunity to help some reefers get back in touch with skills, techniques, and yes- emotions- that they may have either never felt before, or simply lost track of in the frantic-paced marine universe. The reef hobby needs some generalized aquarium "evangelists" out there, trust me!

*Breeding freshwater fishes helps you get your feet wet with skills and protocols that will help you in marine fish breeding efforts- This is a very important, possibly overlooked benefit of freshwater aquarium keeping. Captive breeding is the future of the marine hobby. IMHO, everyone needs to have at least a rudimentary understanding-if not a basic working knowledge- of breeding aquatic animals.

If you can’t raise a baby guppy, you have no chance with a Clownfish, trust me. So, in the freshwater world, where breeding dozens of varieties of fishes is seen as "just something you do", there is a ton of opportunity to cross-pollinate technique, philosophy, and experimentation into the growing marine fish breeding sector. This is a huge deal, in my opinion, and the freshwater practitioner can offer his/her skills to the marine breeding world immediately. It will have real impact on wild populations and the sustainability of the aquarium hobby in general.

I can go on and on…I can hear arguments from both sides (“The Cardinal Tetra is nowhere near as colorful as a Majestic Angel”, or “A reef tank looks like a fruitstand compared to the natural appearance of a planted FW tank.”, etc., etc.) The point is not to create rivalries or foster animosity between the two hobby factions…The idea here is to demonstrate to you that the skills, techniques, and philosophies behind the two aquatic “media” are not only analagous- they are surprisingly interrelated.

I suggest that not only do you keep a saltwater aquarium, but that you attend a marine conference or frag swap and see what these amazing people are all about. Reef hobby “culture” is not all that different from freshwater, once you get past some stubborn attitudes on both sides of the fence- and the chances and benefits of “cross-pollenation” are many and profound! I spent a lot of time talking about this when I was a lecturer in the reef aquarium hobby world.

I hope that I never see another one of those “freshwater is a joke” or "reefers are techie-snobs" kind of posts again. Really, the only real "joke" is that we have this amazing opportunity to learn new skills- or perfect existing ones- that will benefit the general aquatic hobby for generations- and have turned away from it with an elitist attitude in some quarters. Saltwater hobbyists are dedicated just like we are- perhaps even to a greater extent..They’ve been working with reef aquariums for only like 30 years…So it's still a sort of "ground floor" opportunity to apply what's been learned in 100-plus years of freshwater aquarium keeping to this new sector. More than a century!

You think freshwater hobbyists might have learned a few things in that time that can benefit the saltwater world? Absolutely! And, there are a LOT more serious and highly skilled freshwater hobbyists than reefers by an enormous margin..An untapped “market” to develop new reef keepers, and to inject some good things into the saltwater world. And of course, an incredibly important opportunity for freshwater hobbyists to bring some salt-lovers into the new age of specialized freshwater aquariums! 

Final side benefit of aquatic “cross training” with our saltwater friends: If we introduce some experienced saltwater enthusiasts with love to the freshwater world, not only will many give it a try and make the effort to understand that world- they will attempt to convert others…bringing not only new blood, new skills, and new friends to the game- they will help strengthen the overall aquarium hobby, providing a larger, more widespread understanding of what we do, and helping to stand up to the very real external pressures our hobby now faces. 

Final side benefit of aquatic “cross training” with our saltwater friends: If we introduce some experienced saltwater enthusiasts with love to the freshwater world, not only will many give it a try and make the effort to understand that world- they will attempt to convert others…bringing not only new blood, new skills, and new friends to the game- they will help strengthen the overall aquarium hobby, providing a larger, more widespread understanding of what we do, and helping to stand up to the very real external pressures our hobby now faces. 

With that, I’m curious how many of you have marine tanks in your homes, or plan on setting one up…If you spurned saltwater for a time, never lost the fire, or simply enjoy it as another aspect of aquarium keeping…I’d love to hear/see your experiences, as would our readers!

Remember, to keep the saltwater hobby vital, we also have to keep it “fresh.” And of course, to keep the freshwater hobby thriving, we need to inject a little salt into things now and then, too! 

Today’s tale of protein skimmers, phytoplankton, anemones, and Neon Tetras…

Regardless of your water’s specific gravity, I encourage you to stay engaged, share all you know with an open mind and a generous heart.

Time for some aquatic "cross training!"

Stay curious. Stay bold. Stay excited. Stay enthusiastic. Stay creative. Stay open-minded...

And Stay Wet.

Scott Fellman

Tannin Aquatics

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