August 24, 2020


The allure of "throwback" conditions?

I like to think of myself as a very forward-thinking aquarist, and sometimes, it starts with embracing the idea of "throwback" conditions for my fishes!  You know, trying to keep them under environmental conditions which replicate, on as many levels as possible, those under which they've evolved...

Yeah, I've spent a lot of time over the decades playing with the idea of replicating- at least in part- some of the natural environmental conditions under which our fishes have evolved. In fact, one could say that the whole mission of Tannin Aquatics has been to emphasize the practice of replicating-on a number of levels- such conditions.

As a lover of brackish water habitats, I've spent a lot time over the years researching suitable fishes and other aquatic organisms from this environment for aquarium keeping. It's a fascinating world!

Along the way, I've learned a few things. I remember vividly  pissing off some of my surfing buddies on a trip to Fiji a number of years ago, paddling away from the pristine reef to a stifling, smelly Mangrove thicket (apparently filled with alligators, I'd learn later!) to search for fishes. In years of searching, I've stepped in a lot of smelly mud, even collected a mosquito bite or two along the way...

And, I have developed some opinions after seeing these habitats up close and personal! Personally, I think that brackish water habitats are home to more fishes than we think as hobbyists.

Now, sure, many fishes can adapt to brackish water conditions, but I'm more fascinated by the fishes which are actually found naturally in these environments. And it's always interesting when you can find our that a fish which you have previously dismissed as not having typically come from this actually does come from it naturally!

 There are a LOT of examples of fishes which fit this category in the hobby!

I absolutely believe that one of the big factors which is limiting the popularity of brackish water aquariums in the hobby has been the lack of availability and/or information about the origins of the fishes which may be kept in such aquariums.

Based on a recent, informal  survey I did on our Instagram feed, it seems like a lot of hobbyists are "sold" on the idea of a brackish tank, but aren't necessarily sure which fishes we can keep in them!

An interesting dichotomy, for sure!

The environments are compelling...Hobbyists are fascinated by brackish systems, yet the mystery about which fishes actually come from these habitats continues to be an issue. There are opinions, misinterpretations, and downright misconceptions among hobbyists about what fishes are actually from brackish habitats, versus "adaptable?"

And of course, there are surprises!

One of those happy "surprises" is our good friend, the "Endler's Livebearer", Poceilia wingei.

This popular fish is widely kept under "typical livebearer conditions" in the aquarium ( higher pH and harder water). And for years, I was convinced that the fish was found exclusively in these types of habitats...until I dug a bit deeper.

During my research, I learned that there are a number of wild populations form their native Venezuela which apparently inhabit mildly brackish water coastal lagoons and estuaries, for example, Laguna de los Patos, near Cumana, which has definite ocean influence, although it is far less salty than researchers thought it may have been in the past. And the wild populations residing there might very well be considered "endangered", or at least, limited.

Now, this kind of stuff is not "revolutionary" from a hobby standpoint, as it seems like we've known this for some time. Endler's enthusiasts are aware of this, yet it's not discussed all that often.

And although the fish are most adaptable, we don't hear all that much about keeping them in what we'd call "brackish" conditions (like SG of 1.003-1.005-1.010). It's just interesting to ponder and get your head around. It seems to me like the brackish water habitat for this species has not been embraced much from a hobby standpoint.

Why do you think that is?

I think I have an idea why.

I suppose it makes sense, too:

It's far easier to simply give fishes harder, alkaline water than to "mess with adding salt" to their tanks for a lot of hobbyists. Let's face it, the idea of mixing salt and monitoring specific gravity is a big pain, and even a bit intimidating for a lot of hobbyists who are not indoctrinated into the practice.

And, now having been domesticated and selectively bred for decades, wild populations of these fishes are apparently scant, as is natural habitat data, so indeed confirming with great certainty that they are still even occurring in these types of habitats is  difficult, at best, and downright sketchy at worst.

In general, the question about adding salt to livebearer tanks has been debated for a long time, and there are many views on the subject. If you google the topic, you'll literally see directly contradictory references on the first page of the search.

So, are livebearers found in brackish conditions?

Well, sure, many species are...Or, one could more safely say that some populations of many species are found in brackish conditions!

Obviously, the ultimate way to determine if you should or should not add salt to an Endler's or other livebearer tank would be to consider the natural habitats of the population you're working with.

Easier said than done,  of course- because the vast majority of them are now commercially or hobbyist bred- especially Endler's and guppies, of course.

I think the debate around salt and livebearers will go on for a long time!

Yet, with the increasing popularity of brackish water aquariums, and our continuous development of our brackish selection, "Estuary",(wait until you see what we're up to with this stuff in 2021!), we're hoping to see more experiments along this line for many different species of fishes!

Now, you know I've always been a fan of Sort of "re-adapting" even captive-bred specimens of all sorts of fishes (like "blackwater-origin" characins, etc.) to more "natural" conditions (well, "natural" from perhaps a few dozen generations back!) I am of the opinion that even "domesticated" fishes can benefit from providing them with conditions more reminiscent of those from the natural habitats from which they originated.

Yeah, I'm a stubborn ass, and never will buy into the thought that a few dozen captive generations will "erase" millions of years of evolutionary adaptation to specific habitats, and that re-adapting them to these conditions is somehow "detrimental" to them. Perhaps the ultimate example is the Discus, which has been bred for decades in "hard, alkaline water."

Is the idea of "repatriating" them to conditions more like those which they evolved under for eons somehow detrimental to them after a few dozen generations of captive breeding?

Personally, I don't think so. I'm sort of convinced that the rationale here is that it's simply easier for more hobbyists to provide them with "tap water" conditions than it is to manipulate water chemistry for the purpose of recreating some of the natural conditions form which the fishes have evolved under.

In the end, there are a lot of variables in the equation, but I think that the Endler's discussion is just another example of fishes which could benefit from experimenting with "throwback" conditions. I'm by no means anything close to an expert , or even "considerably knowledgable" on these fish, and my opinions are just that- opinions.

Yet, the idea is compelling, isn't it?

Commercially, it may not be practical to do this, but for the hobbyist with time and the inclination, it would be interesting to see where it takes you. We are very proud as a company to offer the natural materials that you can use to help replicate- in form and in function- some of these natural habitats. We want to encourage and facilitate research into this exciting area.

I realize that it's difficult to recreate every aspect of the many different wild habitats which we find compelling. Not everyone has the patience, means, or even the desire to keep their Rasbora at 4.3pH to replicate the peat swamp environment which they came from, or whatever.

Yet, most of us can make impactful changes to the way we keep such fishes, and experiment with creating more "authentic" environmental conditions for them on many levels.

I look forward to many more such discussions and experiments- bringing natural conditions to "domesticated" fishes, and perhaps unlocking some more secrets...or perhaps simply acknowledging what we all know:

That there truly is "no place like home!"

Stay open minded. Stay adventurous. Stay experimental. Stay resourceful. Stay creative. Stay relentless in your pursuit of information...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

August 23, 2020


Preparing for greatness

"Preparation required..."

Words you've heard us utter again and again; precautions you've seen us advise you to take.

Before you throw those seed pods and leaves into your aquarium, you need to do some preparation.


And why are we talking about this again?

Well, partially, because I receive about 3-4 email every single week asking what to do with botanicals after you receive them...So, some people just aren't seeing this stuff, hearing it, reading our instructional cards, social media posts, etc...



I know, it's starting to sound a bit repetitive...

However, with the world botanical-style aquariums growing at an exponential rate, and more and more hobbyists entering into the fray- many of whom are enamored by the beautiful aesthetics of these tanks, it's important-well, actually essential- to revisit this stuff again!

And really, because pretty much all the new vendors into our market space simply appropriate much of the information we put out to help the community, and use it to push their products, let's at least give the lazy-ass motherfuckers something useful to share (and since they're not bothering to provide this information, themselves...)!

Okay, mini-hate-rant over.

"So, you're really into boiling and stepping them, huh?

Yes. I am.

"Why do you do that?"

Well, to begin with, consider that boiling water is used as a method of making water potable by killing microbes that may be present. Most nasty microbes "check out" at temperatures greater than 60 °C (140 °F). For a high percentage of microbes, if water is maintained at 70 °C (158 °F) for ten minutes, many organisms are killed, but some are more resistant to heat and require one minute at the boiling point of water. (FYI the boiling point of water is 100 °C, or 212 °F)...But for the most part, most of the nasty bacteria that we don't want in either our tanks or our stomachs are eliminated by this simple process.

So, wouldn't it make sense to boil our botanicals before we dump them into our aquariums?

Yeah, it would.

Ten minutes of boiling is "golden", IMHO. Of course, we boil for other reasons, too-as we'll touch on in a bit.

For one reason, we boil botanicals to kill any possible microorganisms which might be present on them. Leaves, seed pods, etc. have been exposed to rain and dust and all sorts of things in the natural environment which, in the confines of an aquarium, could  introduce unwanted organisms and contribute to the degradation of the water quality.

And, the surfaces and textures of many botanical items, such as leaves and seed pods lend themselves to retaining dirt, soot, dust, and other atmospheric pollutants that, although quite likely harmless in the grand scheme of things, are not stuff you want to start our with in your tank. 

So, we give all of our botanicals a good rinse.

Then we boil.

Boiling also serves to soften botanicals.

If you remember your high school Botany (I actually do!), leaves, for example, are surprisingly complex structures, with multiple layers designed to reject pollutants, facilitate gas exchange, drive photosynthesis, and store sugars for the benefit of the plant on which they're found. As such, it's important to get them to release some of the materials which might be bund up in the epidermis (outer layers) of the leaf.  As we get deeper into the structure of a leaf, we find the mesophyll, a layer of tissue in which much of photosynthesis takes place.



We use only dried leaves in our botanical style aquariums, because these leaves from deciduous trees, which naturally fall off the trees in seasons of inclement weather, have lost most of their chlorophyll and sugars contained within the leaf structures. This is important, because having these compounds present, as in living leaves, contributes excessively to the bioload of the aquarium when submerged...

Personally, I feel that we have enough bioload going into our tanks, so what add to it by using freshly-fallen leaves with their sugars and such still largely present, right?

Are there variations on this prep theme?

Well, sure. Of course!

Many hobbyists rinse, then steep their leaves in boiling water, rather than a prolonged boil, for the simple fact that exposure to the newly-boiled water will accomplish the potential "kill" of unwanted organisms, which at the same time softening the leaves by permeating the outer tissues. This way, not only will the "softened" leaves "go to work" right away, releasing the beneficial tannins and humic substances bound up in their tissues, they will sink, too! 

And of course, I know many who simply "rinse and drop", and that works for them, too! And, I have even played with "microwave boiling" some stuff (an idea forwarded on to me by Cory Hopkins!). It does work, and it makes your house smell pretty nice, too!

It's not a perfect science- this leaf preparation "thing."

And I admit, I've changed some of my approaches over the years...I'd be foolish not to.

Of course, the fundamental idea behind preparation of botanicals hasn't really changed too much.

Leaf preparation has evolved quite a bit, actually! Many aquarists have developed simple approaches to leaf prep that work with a high degree of reliability. Now, there are some leaves, such as Magnolia, which take a longer time to saturate and sink because of their thick, waxy cuticle layer. And there are others, like Loquat, which can be undeniably "crispy", yet when steeped begin to soften and work just fine.

There is no 100% guaranteed way to perfectly prep every botanical or leaf the same way every single time.

You have to be flexible and adaptable.

So why do we soak after boiling?

Well, it's really a personal preference thing.I suppose one could say that I'm excessively conservative, really. 

I feel that it releases any remaining pollutants and undesirable organics that might have been bound up in the leaf tissues and released by boiling, which is certainly arguable, but is also, IMHO, a valid point. And since we're a company dedicated to giving our customers the best possible outcomes- we recommend being conservative and employing the post-boil soak.

The soak could be for  a half an hour, an hour or two, or even real "science" to it. Some aquarists would argue that you're wasting all of those valuable tannins and humic substances when you soak the leaves overnight after boiling. I call bullshit on that. My response has always been that you might lose some, but since the leaves have a "lifespan" of weeks, even months, and since you'll see tangible results from them (i.e.; tinting of the water) for much of this "operational lifespan", an overnight soak is no big deal in the grand scheme of things.

So don't stress over that, okay?

Do what's most comfortable for you- and okay for your fishes.

When it comes to to other botanicals, such as seed pods, the preparation is very similar. Again, most seed pods have tougher exterior features, and require prolonged boiling and soaking periods to release any surface dirt and contaminants, and to saturate their tissues to get them to sink when submerged! 


And quite simply, each botanical item "behaves" just a bit differently, and many will require slight variations on the theme of "boil and soak", some testing your patience as they may require multiple "boils" or prolonged soaking in order to get them to saturate and sink.

Yeah, those damn things can be a pain! 

However, I think the effort is worthwhile.

Now, sure, I hear tons of arguments which essentially state that "...these are natural materials, and that in Nature, stuff doesn't get boiled and soaked before it falls into a stream or river." Well, damn, how can I argue with that?

The only counterargument I have is that these are open systems, with far more water volume and throughput than our tanks, right? Nature might have more efficient, evolved systems to handle some forms of nutrient excesses and even pollution. It's a delicate balance, of course.

I believe that some steps to prepare botanicals before adding them to our aquariums is not only beneficial because it helps to cleanse them of some of the aforementioned pollutants- the practice itself creates "ritual" in our speciality, which in turn, helps to create "best practices" which can benefit all who play with these types of aquariums.

I even espouse a quick rinse when you use our "Shade" tinting sachets- even though the botanicals continued within the mix are carefully cleaned before they're added to the sachets.

Like all botanicals, a quick rinse with water serves to saturate the find blend within, and lets them "go to work" more quickly.

Although "Shade" is a carefully formulated  well-tested alternative to "dumb old tea bags", it's not a "miracle" product.  It just isn't. "Shade" won't guarantee that you'll get your wild Cardinal Tetras to spontaneously spawn on command. It won't cure fungal diseases. It WILL help you achieve the color effects you are looking for. It WILL offer many of the same potential health benefits to your aquatic animals that using our botanicals in your aquariums in their "natural" form will. Of course, even those benefits are STILL not fully understood, 100% predictable, or really all that well-defined! (C'mon, you didn't think I could guarantee THAT kind of stuff, did ya?)

It's a cool product, if I may say so, myself!

In the end, preparation techniques for botanical materials are as much about prevention as they are about "preparation."

To summarize- by taking the time to properly prepare your botanical additions for use in the aquarium, you're doing all that you can to exclude unwanted bacteria and microorganisms, surface pollutants, excess of sugars and other unwelcome compounds, etc. from entering into your aquarium. 

Like so many things in our evolving "practice" of perfecting the blackwater, botanical-style aquarium, developing, testing, and following some basic "protocols" is never a bad thing. And understanding some of the "hows and whys" of the process- and the reasons for embracing it-will hopefully instill into our community the necessity- and pleasures- of going slowly, taking the time, observing, tweaking, and evolving our "craft"- for the benefit of the entire aquarium community.

The practice of botanical-style aquariums is still very much "open source"- we're all still writing the "best practices"- and everyone is invited to contribute! 

That's part of how we prepare for greatness, isn't it?

It is.

Stay engaged. Stay fascinated. Stay observant. Stay excited. Stay involved...

And Stay Wet.


Scott Fellman

Tannin Aquatics


August 22, 2020


The ins-and-outs of water quality and its role in the botanical-style aquarium.

One of the great "contradictions" about the botanical-style aquarium is that we run a tank full of all sorts of decomposing leaves and seed pods and stuff, yet value high water quality- and indeed- achieve it-on an ongoing basis. We have this enormous quantity of stuff breaking down, yet somehow manage to maintain high standards of cleanliness and good water quality in our tanks, don't we?

"Cleanliness" is something that gives me a lot to think about, in the context of botanical-style aquariums. I mean, when it comes to managing a botanical-style aquarium, you are already at a sort of "disadvantage" when it comes to running a "spotlessly clean" aquarium. You've essentially committed to a tank which contains large quantities of natural materials, busily recruiting biofilms and fungal growths, all the while, in the process of breaking down.

At any given time, the bioload in your aquarium is likely as great- or greater- than a fully stocked community aquarium with lots of well fed fishes. I mean, decomposing leaves, right?


So, it certainly makes sense to ask ourselves what the implication is of all this "stuff" breaking down in our tanks? Are we simply adding tons of organic materials in there for our beneficial bacteria to handle, just sort of "treading water" to keep things from falling into biological chaos, or are we actually helping foster and feed a small "food chain" of organisms which collectively assimilate this material and the associated organic compounds it produces?

Or, is it somewhere in between?

There must be a thousand ways to set up an aquarium and operate it. In fact, its probably several times that amount. And no one can ever seem to agree what the "best" way to go is. And that's okay. There are a lot of cool approaches you can try. So, while we might disagree on the best approach or style, we all seem to have a common goal:

Providing the best possible environment for our fishes.

Pretty much every really serious aquarium hobbyist can agree on one thing: It's important to have information about what's going on in his or her aquariums. Observation, collection of data, and interpretation of the information gathered have been keys to our success in so many areas of endeavor in the hobby.

And, I admit, our botanical-style aquariums are a bit of an enigma.

I mean, we have tanks with all of this stuff decomposing in the water, yet manage to maintain high water quality and stability for extended periods of time without any real "magic", in terms of procedure or equipment. 

What gives?

And of course, not being a scientist makes it kind of challenging for me to make all kinds of assertions about water quality and chemistry, so I will at least try to focus on what we want to achieve, and what we can measure, water quality-wise, and how botanical-style aquariums seem to be able to "pull it off" given their vast quantities of leaves, seed pods, etc.

Now, we kind of have a pretty good "handle" on which tests make the most sense for our pursuits. It's a given that ammonia, nitrite, pH and DKH are the key indicators which most hobbyist will want to know about. 

And then, there are the tests which give us information on the quality of the environment we've created- nitrate and phosphate. Nitrate (NO3) is not necessarily considered "toxic" at a specific level, although a typical rule of thumb is to keep readings under 50 mg/l- or better still, 20mg/l or less, for most fishes at various stages of their life cycle.  

Although there is no "lethal dose", as indicated above, and many fishes can tolerate prolonged exposure to up to 500 mg/l of nitrate, studies have revealed that prolonged exposure to elevated levels of nitrate may reduce fishes' immunity, affecting their internal functions and resistance to disease.

Many fishes can adapt- to a certain extent- to a gradual increase in nitrate over time, although long-term physiological damage can occur. And of course, some fishes are much more sensitive to nitrate than others, displaying deteriorating overall health or other symptoms at much lower levels..

One of the interesting things about nitrate is that it can and will accumulate and rise over time in the aquarium if insufficient export mechanisms (ie; water exchanges, lack of chemical or biological filtration capacity exist within the aquarium. This, of course, gives the impression that fishes are "doing okay" when the reality is that they are exposed to a long-term stressor. The presence of plants, aquatic or terrestrial, known for their utilization of nitrate as a growth factor, is also considered a viable way to reduce/export nitrates, along with overall good husbandry (ie; stable fish population, proper feeding technique, etc.)

In our botanical-filled, natural-style aquariums, I have personally never observed/measured high level of nitrate-with or without plants. In fact, with a good husbandry regime in place, undetectable (on a hobbyist-grade test kit, at least) levels of nitrate have been the norm for my systems. I think that the highest nitrate reading I've personally recorded in a botanical-style system which I maintained was around 10 mg/l.

Why is this?

Well, I personally feel that well-maintained systems, including our heavily botanically-influenced ones, offer a significant "medium" for the growth and proliferation of beneficial bacteria species, such as Nitrospira. I have a totally ungrounded "theory" that the presence of botanicals, although in itself a contributor to the the biological load on the aquarium, also is a form of "fuel" to power the denitrification process- a carbon source, if you will, to elevate levels of biological activity in an otherwise well-maintained system. 

Okay, sounds like a lot of cobbled-together "mumbo jumbo", but I think there is something to this.

I mean, when you think about it, a botanically-rich aquarium, with leaves and other materials, fosters bacteria, fungi, biofilms, and supports crustaceans and other organisms which can consume the botanicals as they breakdown, along with fish wastes and other organics.


Something to think about!

I find this among the most exciting potential benefits of a botanical-style aquarium. In fact, I believe that, once serious scientific study is conducted on this stuff, it may prove to be a foundational component of the botanical-style aquarium. We will embrace the addition and decomposition of natural materials in our aquariums as a sort of "catalyst" to create a stable, productive closed ecosystem, which effectively metabolizes the materials within...

Just like in Nature.

A sort of "on board" biological filtration system, if you will, with the added benefit that fishes will consume some of these organisms. Perhaps, even the basis for a sort of "food web", something that we know exists in all natural aquatic ecosystems.

The other measure of water quality that most of us should consider is phosphate (PO4). It's a salt of phosphoric acid- an inorganic chemical. It's an essential chemical for the growth of plants, and other living organisms. Phosphate gets a lot of "bad press" in the hobby as a contributor to the growth and proliferation of algae, which it is. However, it's really only half of the equation, as algae only grows if nitrogen is also present...So, it's a contributor to algae issues and overall water quality- not the main culprit. 

In the reef hobby, phosphate has been vilified as a growth inhibitor to coral, and all manner of additives, reactors, and removal media have been developed to combat it. The reality, IMHO, is that phosphate- although a great measure of overall water quality, tends not to become a problem in an otherwise well-managed aquarium. It gets into our systems in the first place via food, and will accumulate if mechanisms for its absorption/utilization or removal don't exist. 

So, yeah- perform those regular water exchanges.

Oh, and both nitrate an phosphate are present in tap when I espouse the use of an expensive RO/DI unit to pre-treat your tap water, I'm recommending a means to eliminate it at the source, giving you at least a good start. For a variety of reasons we've touched on numerous times here in "The Tint", reverse osmosis/deionization units, albeit somewhat pricy, are, in my opinion, an essential piece of equipment for any serious hobbyist. 

So, this is all well and good...this discussion of how botanicals themselves help foster a biologically-rich closed ecosystem, capable of assimilating many of the dissolved organics which have long been vilified in aquariums. Yeah. Yet, how do we keep water quality high in our tanks on a practical level?

You apply the same level of attention to the blackwater/brackish botanical-style aquarium as you would to any other. 

And of course...this is the elegant segue into the part about your "weekly maintenance regimen" yet again, right?

Well, yeah. It's a foundational practice. One which I really shouldn't have to be talking about here...But you asked, so...How much to change?

Do "whatever floats your boat", as they say.

If you're a bi-weekly-type of tank maintenance person, do that. If you're a once-a-month kind of person...Well, you might want to re-examine that! LOL. Botanical-style blackwater tanks, although remarkably stable once up and running, really aren't true "set-and-forget" systems, IMHO.

You'll want to at least take a weekly or bi-weekly assessment on their performance and overall condition. Now, far be it from me to tell YOU- the experienced aquarist-how to run your tanks. However, I'm just sort of giving you a broad-based recommendation based upon my experiences and those of many others over the years with these types of systems.

You need to decide what works best for you- and your animals, of course...

Now, remember, you're dealing with a tank filled with decomposing botanical materials. Good overall husbandry is necessary to keep your tank stable and healthy- and that includes the dreaded (by many, that is) regular water exchanges. As we pointed out, at the very least, you'll likely be cleaning and/or replacing pre filter media as part of your routine, and that's typically a weekly-to bi-weekly thing.  

Just sort of "goes with the territory" here.

During water exchanges, I typically will siphon out any debris which have lodged where I don't want 'em (like on the leaves of that nice Amazon Sword Plant right up front, or whatever), but for the most part, I'm merely siphoning water from down low in the water column. I'm a sort of "leave 'em alone as they decompose" kind-of-guy.

It's really not something that is unique to this style of aquarium. The main difference between these types of tanks and almost all others is that we tend to go over the top at embracing and encouraging a lot of natural processes to occur in our tanks, as opposed to trying to remove every single trace of organics.

In general, the water quality of our botanical-influenced, natural systems is something worthy of a lot of research, experiments, and discussion in our community. There is so much interesting stuff happening in our tanks- and so many things we don't know...Specifically, how very low pH aquariums are best kept biologically stable. 

That's another topic for another time, for sure!

And of course, the function- both biologically and environmentally- of deep leaf litter beds I the aquarium. We have just scratched the surface of managing truly realistic, functional leaf litter beds at scale in our systems. There's so much more to learn!

We have taken our first tentative footsteps beyond what has long been accepted and understood in the hobby, and are starting to ask new question, make new observations, and yeah- even a few discoveries- which will evolve the aquarium hobby in the future.

So, in the mean time- apply common sense...the stuff you've learned since you were a beginner about maintenance and husbandry, and mix in a little faith in Nature and the work she does; be a bit more accepting of her processes, and everything should work out about right.

Stay curious. Stay studious. Stay experimental. Stay bold. Stay diligent...

And Stay Wet.


Scot Fellman

Tannin Aquatics 

August 21, 2020


Building a microcosm. Starting from the bottom...

As you know by now, we're completely obsessed with how diverse aquatic ecosystems arise, function, and sustain themselves, and how we can interpret this for application to our aquarium work. 

It's a lot more interesting, when you examine the subject more closely- especially from the perspective of how these aquatic habitats came to be, and what implications they have for fish stuff.

And so much of what makes these ecosystems operate so successfully starts with the bottom!

Stream and river bottom composition is affected by things like regional weather, current, geology, the surrounding dry lands, and a host of other factors- all of which could make planning your next aquarium even more interesting if you take them into consideration!

We've touched on these in some recent posts, and we'll definitely dive deeper in upcoming blogs. There's more to this type of aquarium just the accumulation of leaves and such.

It's pretty interesting...

If we focus on shallow tributaries of streams and flooded forest floors, which are one my personal areas of interest, it's important to note that the volume of water entering the stream, helps in part determine the amount and size of sediment particles, leaves, beaches, seed pods, and the like that can be carried along, and thus comprise the substrate and it's contours. The mixing of materials not only looks interesting- it's a reflection of the diversity and vibrancy of the underwater environment.

One of the things you notice in the images above of natural underwater substrates is that they're usually anything but squeaky-clean, ultra-white sand. Rather, they're often sediment-filled, covered with stringy fungal growths, biofilms, and even a spot or two of algae. There is a fair amount of detritus accumulating in the substrate materials. And, as you know, detritus is not the enemy that we've made it out to be. Rather, it's a source of food for many aquatic animals, helping to literally "power" the ecosystem in which they are present.

This is something we can-and should- absolutely replicate in our aquariums. Don't be afraid of sediments and even detritus accumulating on top of your leaves and's exactly what you see in Nature, and our fishes are ecologically adapted to such habitats.

In Nature, the composition of bottom materials and the depth of the channel are always changing in response to the flow in a given stream, affecting the composition and ecology in many ways. Some of these changes are actually the result of the fishes "working them."

 In the words of our friend, author Mike Tuccinardi:

"One of the things that is most striking when you spend time below the water’s surface in this sort of environment is that the fish aren’t just passive inhabitants—they’re actively involved with their habitat, interacting in a very particular way. Apistogramma species aren’t just hanging out, they’re fighting turf wars among piles of dense leaf litter, even making their own piles by moving leaves and other bits of detritus to the center of their territories.

Suckermouth catfish, whether Farlowella or Ancistrus, are actively exploring recently-submerged branches and roots, looking for a rich patch of biofilm or algae to feast on. Eartheaters and many other species of cichlids—even Severums, Angelfish, and Discus—are patrolling the bottom, taking big mouthfuls of sand and organic material to sift out any tasty morsels. It’s a big, organic mess, literally made up of various botanicals and these fish are having a field day in it."

These dynamic habitats are not difficult to replicate in the aquarium. We need to understand that they play a functional and aesthetic role in the overall aquarium, as we've touched on many times here. Realizing that placing leaves and botanical materials on the bottom of the aquarium is not simply making an aesthetic statement. Rather, it's an homage to the function of the dynamic habitats we love so much.

Feeding dynamics play a huge role in the interactions which fishes have with the bottom. As we've talked about previously, aquatic invertebrates and crustaceans are one of the primary foods consumed by many fishes which reside in tropical streams, and the amounts and types are dictated by the environment of the stream, which includes factors like the surrounding topography, current, elevation, surrounding plant growth, etc.

Many fishes, like Headstanders, characins, and others, simply consume tiny crustaceans as part of their sediment feeding activity. Now that we're more likely to set up aquariums with fine, silty sediments stocked with tons of little copepods and worms and such, these experiments may yield very interesting results!


It is absolutely possible to create a real "active substrate", filled with these creatures, and to be able to "pre-stock' it with cultures of small life forms prior to the introduction of fish! And of course, there are ways to replenish the population of these creatures (and even the substrate itself) periodically, resulting in extremely productive systems, too!

 An interesting experiment to think about, huh? Even more interesting to actually execute. Could such a system, with a heavy "substrate-centric" focus be successfully managed long-term?


For sure.

A well-managed substrate, in which uneaten food and fish feces are not allowed to accumulate to excess, and in which regular nutrient export processes are embraced, it's not an issue, IMHO. When other good practices of aquarium husbandry (ie; not overcrowding, overfeeding, etc.) are empIoyed, a botanically-"enriched" substrate can enhance- not inhibit- the nutrient processing within your aquarium and maintain water quality for extended periods of time.

Like many of you, I have always been a firm believer in some forms of nutrient export being employed in every single tank I maintain. Typically, it's regular water exchanges. Not "when I think about it', or "periodically", mind you.

Nope, it's weekly. 

Now I'm not saying that you can essentially disobey all the common sense husbandry practices we've come to know and love in the hobby (like not overcrowding/overfeeding, etc.) and just change the water weekly and everything's good.

And I'm not suggesting that the only way to succeed with adding botanical materials to the substrate is to employ massive effort at nutrient export; the system  otherwise teetering on a knife's edge, with disaster on one side and success on the other. 


Our aquariums are far more resilient than that. If we set them up to be. And that means "configuring" them to be successful, diverse, biologically-rich ecosystems at all levels.

There is a lot of science to sift through about natural river/stream/pond substrates and how they function in the wild, and much of this can be applied to what we do in our closed aquariums. Of course, an aquarium is NOT a stream, river, etc. However, the same processes and "rules" imposed by Nature that govern the function of these wild ecosystems apply to our little glass and acrylic boxes.

It's a matter of nuance and attempting to understand how they work.

My goal is to keep us in the mindset of thinking about our aquariums as little "microcosms", not just "aquatic dioramas."

This is what will continue to move the hobby forward, IMHO.

And of course, the whole idea of a rich, sediment-sand-and-soil substrate enriched with botanical materials is completely in line with the "best practices" we've developed as a community to create dynamic, botanical-style aquariums. In our case, not only will there be an abundance of trace elements and essential plant nutrients be present in such a substrate, there will be the addition of tannins and humic substances which provide many known benefits for fishes as well.

The best of both worlds, I think!

It's time to really dig deep into the art and science of creating an entire ecosystem in the confines of our aquariums!

I can't think of anything more exciting than that! 

Stay excited. Stay inspired. Stay resourceful. Stay educated...

And Stay Wet.


Scott Fellman

Tannin Aquatics 



August 20, 2020


The "hands-off" mindset...

We talk a lot about patience here, especially in the context of working with our botanical-style blackwater aquariums. We've pretty much force-fed you the philosophy of not rushing the evolution of your aquarium, of hanging on during the initial breakdown of the botanicals, not freaking out when the biofilms and fungal growths appear...patience. Embracing the process.


What goes hand-in-hand with patience and accepting Nature's process is the concept of...well, how do I put it eloquently...leaving "well enough alone"- not fucking with stuff!

Yeah, that means not intervening in your aquarium when no intervention is really necessary. I mean, sure, it's important to take action in your aquarium when something looks like it's about to "go south", as they say- but the reality is that good things in an aquarium happen slowly, and if things seem to be moving on positive arc, you need not "prod" them any further. 

I can't tell you how many promising tanks have been "detoured" by well-meaning hobbyists who, in a state of panic, despair, or plain-old impatience- jumped in and "edited" what was going on- and in the process, ultimately prevented their aquarium from developing into something truly special!


I think this is one of the most underrated mindsets we can take as aquarium hobbyists. Now, mind you- I'm not telling you to take a laissez-faire attitude about managing your aquariums. "Oh, that rising ammonia level is just a passing thing. No biggie!" 


What I am suggesting is that pausing to contemplate what will happen if you intervene is sometimes more beneficial than just "jumping in" and taking some action without considering the long-term implications of it. It's one thing to be "decisive"- quite another to be “overreactive!"

When that fish starts hiding in the corner, one of the first words out of our mouths is "disease!" Well, IS that what's happening, or is the fish merely "chilling out", or perhaps startled, or even- guarding a clutch of eggs? Your first action shouldn't be to net the fish out, tearing up the aquascape and generally freaking out every other fish in the tank in the process, right?

I mean, consider what could have precipitated the behavior before springing into action that might have worse consequences for your aquarium and the inhabitants. Maybe it's literally just a "passing behavior" for the fish. Look for actual disease or physical injury signs. Consider that what you're seeing might be a complete "non issue", right?

Like any living creature, fishes will occasionally engage in unexpected behaviors, which are not necessarily indicative of an illness or problem.

How do you know what to do- or if you should do something? Well, besides educating yourself more on what is "normal" or what you should be expecting in your aquarium, you need to engage in one common behavior...

You observe. 

It's what you already do a lot of anyways, right?

Observe your tank constantly, which will give you a sort of "baseline" for it's normal function, for the fishes' behaviors, the operational "norms" of the equipment, the environmental parameters, etc. Just because a blog or a book or a friend tells you that "x" is "not right" doesn't necessarily mean that it isn't in your aquarium. 


Sure, if you have ammonia, something is not right. Duh.

However, if the otherwise healthy Cryptocoryne is growing more slowly in your tank than what "the books" say, it may not be a "problem", right? There could be a lot of different reasons- many of which are not remotely associated with "problems." The key to understanding when stuff is going wrong is to know what it's like when things are going right in your tank. 


Observe. Constantly.


Document your tank and it's operation.

Keep a notebook, take pics, whatever it takes. One of the things we love to see are the tank "progression pics" that you share with us on Facebook. You can see how the botanicals begin to break down, how the water "tints", how the fish color up, etc. It's part of the observation process, which is part of the understanding process, which is part of how you determine if you need to leave stuff alone, or spring into decisive action to circumvent a potential disaster!




It's that simple. You probably already do this to some extent. However, it's easy to forget when it's "your babies", right? Online aquarium forums are filled with frantic questions from members about any number of "problems" happening in their aquariums, a good percentage of which are nothing to worry about. You see many of these hobbyists describe "adding 100 mg of _______ the next day, but nothing changed..." (probably because nothing was wrong in the first place!). 

Our botanical-style aquariums embrace radically different processes and occurrences- stuff which not only functions I na unique manner, but simply looks different than what we're used to seeing in aquariums. Stuff which may challenge what we've been indoctrinated to believe is "okay" or "normal."

You need to understand what "normal" is for the type of system you're managing. I can't stress this enough.


Now, sure, sometimes there ARE significant problems that we freak out about, and should jump on-but we have to "pick our battles", don't we? Otherwise, every time we see something slightly different in our tank we'd be reaching for the medication, the net, adding another gadget (a total reefer move, BTW), etc.


Let nature take its course on some things.




For example, you have biofilms appearing on your botanicals. Understand what they actually are, and why they appear, and that they are normal- and suddenly, those yucky-looking strands of goo don't seem quite so menacing. When you see pics from the Amazon showing biofilms and algae growth all over the place, you start to understand that, just like the brown water and decomposing leaves, they're an important, integral, and totally normal part of the habitat we replicate.


Learn what "normal" is. 


Realize that nature will plot a course with minimal intervention on our part. Sure, when long-term health or even the enjoyment of your system is tarnished by some of these things, intervention is necessary. Be thoughtful about this stuff, though. Excessive algae, for example, is indicative of an excess nutrient issue, and can be managed with simple adjustments. However, for so many things, the best "course of action" is to let Nature do as She's done for eons...

Embrace nature.

Understand how our closed systems are still little "microcosms", subject to the rules laid down by the Universe. Realize that sometimes- more often than you might think- it's a good idea to "leave well enough alone!”


That's the essence of the "hands-off" mindset.


Stay kind to yourself. Stay thoughtful. Stay observant. Stay measured....


And Stay Wet.



Scott Fellman

Tannin Aquatics 

August 19, 2020


Working it... Nature's processes...

Part of the whole "game" of the botanical-style aquarium is understanding how, why and what happens to terrestrial materials when they're placed in water.

Nature has been working with terrestrial materials in aquatic habitats for eons.

And Nature works with just about everything you throw at her!

She'll take that seemingly "unsexy" piece of wood or rock or bunch of dried leaves, and, given the passage of time, the action of gravity and water movement, and the work of bacteria, fungi, and algae- will mold, shape, evolve them into unique and compelling pieces, as amazing as anything we could ever hope to do...

This is true in both the wild habitats and the aquarium, of course.

The same processes and function which govern what happens to these materials in the wild occur in our aquariums. And, if we reject our initial instinct to "edit" what Nature does, the aquarium takes on a look and vibrancy that only She can create.

We're hitting on this "what happens when.." theme again today, because we've seen more and more newcomers to our world aspiring to work with botanicals. Although at this point in 2020, the calendar matters a lot less than it did in previous years thanks to the pandemic, the approaching autumn seems to be that "trigger" which stimulates the creation of new aquariums. 

And new aquariums, combined with new botanical-style aquarium enthusiasts bring with them new expectations, new ideas, and new processes to understand.

Oh- mental shifts, of course! (You knew I'd say that.)

We also have to re-adjust our aesthetic preferences to accept the appearance of these processes. We need to understand why biofilms form, why terrestrial materials decompose underwater, and how this impacts-and benefits- the environment in our aquariums.

There is more to this than just crafting a "look and layout."

You don't have to start with a real high concept, in terms of laying out your botanicals and leaves. A lot of hobbyists ask me about the best way to place botanicals in their tanks, and the simple truth is that there IS no "best way."  You can place seed pods and leaves and such wherever you want to in the tank, but processes like water movement, decomposition, and the activities of our fishes will sort of "re-distribute" these materials.

Again exactly what happens in Nature. In an ironic twist on the traditional way of 'scaping and running aquariums, WE as hobbyists actually have to accept a certain amount of "editing" by Nature!

So, what exactly happens when terrestrial materials- like leaves, seed pods, and wood, are submerged in water?

Let's talk a cursory look at it!

Anyone who's ever cured a piece of wood, thrown in a bunch of seed pods, or laid down some leaves in their aquarium has seen the emergence of biofilms and fungal growth.

This much-maligned stuff is something those of us who play with leaves and botanicals know all too well. It's something we see in our aquariums, as well as in the wild aquatic habitats around the world.Biofilms form when bacteria adhere to surfaces in some form of watery environment and begin to excrete a slimy, gluelike substance, consisting of sugars and other substances, that can stick to all kinds of materials, such as- well- in our case, botanicals.


It starts with a few bacteria, taking advantage of the abundant and comfy surface area that leaves, seed pods, and even driftwood offer. The "early adapters" put out the "welcome mat" for other bacteria by providing more diverse adhesion sites, such as a matrix of sugars that holds the biofilm together.

Since some bacteria species are incapable of attaching to a surface on their own, they often anchor themselves to the matrix or directly to their friends who arrived at the party first.

 And we could go on and on all day telling you that this is a completely natural occurrence; bacteria and other microorganisms taking advantage of a perfect substrate upon which to grow and reproduce, just like in the wild. Freshly added botanicals offer a "mother load"of organic material for these biofilms to propagate, and that's occasionally what happens - just like in Nature.  

They are not only typically harmless in aquariums, they are utilized as a supplemental food source by a huge variety of fishes and shrimps in both nature and the aquarium. They are a rich source of sugars and other nutrients, and could prove to be an interesting addition to a "nursery tank" for raising fry if kept in control. Like, add a bunch of leaves and botanicals, let them do their thing, and allow your fry to graze on them!

And then, there are the fungi.

Fungi feed by absorbing nutrients from the organic material in which they live. Fungi do not have stomachs, and must digest their food before it can pass through the cell wall into structures called hyphae (the threads that form the body of a fungus- the part that you see all over that sexy piece of wood you just added your tank!). Hyphae secrete acids and enzymes that break the surrounding organic material down into simple molecules they can easily absorb.

Fungi have evolved to use a lot of different items for food. Some are decomposers living on dead organic material like leaves. these are the guys we typically encounter in our botanical-style aquariums' leaf litter/botanical beds!

Fungi reproduce by releasing tiny spores that then germinate on new and hospitable surfaces (ie, pretty much anywhere they damn well please!). These aquatic fungi are involved in the decay of wood and leafy material. And of course, when you submerge terrestrial materials in water, growths of fungi tend to arise.

Fungi tend to colonize wood because it offers them a lot of surface area to thrive and live out their life cycle. And cellulose, hemicellulose, and lignin- the major components of wood and botanical materials- are degraded by fungi which posses enzymes that can digest these materials! Fungi are regarded by biologists to be the dominant organisms associated with decaying leaves in streams, so this gives you some idea as to why we see them in our aquariums, right?

And of course, many fishes and invertebrates which live amongst and feed directly upon the fungi and decomposing leaves and botanicals contribute to the breakdown of these materials as well! Aquatic fungi can break down the leaf matrix and make the energy available to feeding animals in these habitats.

And look at this little gem I found in my research:

"There is evidence that detritivores selectively feed on conditioned leaves, i.e. those previously colonized by fungi (Suberkropp, 1992; Graca, 1993). Fungi can alter the food quality and palatability of leaf detritus, aecting shredder growth rates. Animals that feed on a diet rich in fungi have higher growth rates and fecundity than those fed on poorly colonized leaves. Some shredders prefer to feed on leaves that are colonized by fungi, whereas others consume fungal mycelium selectively..."

"Conditioned" leaves, in this context, are those which have been previously colonized by fungi! They make the energy within the leaves and botanicals more available to higher organisms like fishes and invertebrates! 

After all of this, comes the break down- the decomposition- of the materials we add to our tanks.

If there is one aspect of our botanical-style aquariums which fascinates me, it's the way they facilitate the natural processes of life- specifically, decomposition.

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

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

A very apt descriptor, if you ask me! 

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

Decomposition of plant matter-leaves and botanicals- occurs in several stages.

It starts with leaching -soluble carbon compounds are liberated during this process. Another early process is physical breakup or fragmentation of the plant material into smaller pieces, which have greater surface area for colonization by microbes. 

Does the liberation of carbons, sugars, etc. in our systems impact the water quality of our aquariums? Of course it does! And you need to monitor water quality in your aquariums regularly, to establish what's "baseline" for your system.

It's important to remember that leaves and such are simply not permanent additions to our 'scapes, and if we wish to enjoy them in their more "intact" forms, we will need to replace them as they start to break down. 

This is not a bad thing.

Much like flowers in a garden, leaves will have a period of time where they are in all their glory, followed by the gradual, inevitable encroachment of biological decay.

At this phase, you may opt to leave them in the aquarium to enrich the environment further and offer a new aesthetic, or you can remove and replace them with fresh leaves and botanicals.

Again, this is very much replicates the process which occur in nature, doesn't it? Stuff either remains "in situ" as part of the local habitat, or is pushed downstream by wind, current, etc.

(If you haven't figured it out by now, pretty much everything we do in a botanical-style blackwater aquarium has a "natural analog" to it!)

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

Nature works it!

Understanding that decomposition is an amazing process by which Nature processes materials for use by the greater ecosystem is really important.

It's the first part of the recycling of nutrients that were used by the plant from which the botanical material came from. When a botanical item decays, it is broken down and converted into more simple organic forms, which become food for all kinds of organisms at the base of the ecosystem.

In aquatic ecosystems, much of the initial breakdown of botanical materials is conducted by detritivores- specifically, fishes, aquatic insects and invertebrates, which serve to begin the process by feeding upon the tissues of the seed pod or leaf, while other species utilize the "waste products" which are produced during this process for their nutrition.

In these habitats, such as streams and flooded forests, a variety of species work in tandem with each other, with various organisms carrying out different stages of the decomposition process.

And we can replicate part of this process in our aquariums. I'm very confident about that.

Nature works it.

Yet, we have to play with Her.

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

It's an inevitable result of the processes by which Nature utilizes botanical systems in our aquariums.

So, yeah- there IS a lot to consider when utilizing botanical materials in your aquarium. It's far, far beyond the idea of just "dumping and praying" that has been an unfortunate "model" for how to utilize them in our aquariums for many years. It's more than just aesthetics alone...the "functional aesthetic" mindset- accepting the look and the biological processes which occur when terrestrial materials are added  to our tanks is a fundamental shift in hobby thinking.

By studying the process of decomposition in Nature and in our aquariums, I believe that we are contributing to an exciting progression of the art and science of aquarium keeping!

Stay studious. Stay observant. Stay diligent. Stay creative...

And Stay Wet.


Scott Fellman

Tannin Aquatics 




August 18, 2020


"We interrupt this aquarium..."

Every aquarium is a unique microcosm, with different looks, goals, and processes that it embraces. Each aquarium has different factors which contribute to its function and evolution.

Processes which cannot be interrupted if the aquarium is to evolve. Processes which must be left in place.

As I've been doing lately, I find it fun to look at some of the tanks I've created recently which take this philosophy to heart.

One of my faves has been my brackish water mangrove aquarium, which took well over a year, to really evolve into something exactly like I envisioned...It simply wasn't "there" after a month or two, or even six. Our botanical style tanks, with few exceptions- just don't start looking their best- all "earthy" and "funky" and...established- for a few months, typically.  growth of beneficial microfauna.

The brackish tank has embraced all of the things we've talked about here over the years- deep, soft substrates, decomposing leaves, occasional biofilms, tinted water, and a diverse assemblage of micro and microfauna. These are unusual things to embrace in a brackish water aquarium.

To terminate them "mid-evolution" is really a kind of shame! The possibilities are too incredible for you to just "stop them in place!" 

Of course, there are a few things you could do to sort of "expedite" the "established" look of a botanical-style tank, but they're really just sort of "hacks" (ugh I hate that word!)- and are no substitutes for just letting a tank evolve over time naturally.

What are they, you ask?

Well, you could use some botanicals and partially decomposed leaf litter, substrate, and even water from an established botanical-style tank to give you a bit more of an "evolved" vibe and perhaps some function. I've done this many times over the years. 

And, if doing this for purely "functional" reasons as opposed to just trying to "hack" the look- I can actually see tremendous merit to this idea.

Adding sand or gravel from an established tank to "jump-start" a new one has been standard practice in marine aquariums for decades, and in freshwater as well. Doing this with botanical materials- rich with detritus, biofilms, fungal growth, and beneficial bacteria- is simply the botanical-style version of this time-honored process, right?

It is.

Yet, there is no substitute for patience and the passage of time. You can't get results of processes which take time to evolve by "hacking" them. They'll only get you so far.

As we drum into your head time and again, patience is the key.

It's so fundamental that I will say it yet again. 

The idea of letting Nature take over some of the evolution of your aquarium is so important, so essential to the work we do with botanical-style aquariums that I imagine I'll write about this a few hundred more times before they put me out to pasture! 

Again- just because stuff looks "weird" or different than what we've been indoctrinated to believe doesn't mean that it's a "problem" or somehow "bad."  It just doesn't. There is absolutely nothing wrong with stuff like biofilms, decomposing leaves, and tinted water. It's all about how we perceive it.

Sure, many of these things go completely against everything that we were taught in the hobby to accept as "healthy" or "normal"- but the reality is, they are all perfectly "normal", healthy, and natural.

Looking back on some of my favorite tanks that I've executed in the past few years, it becomes increasingly obvious to all that these systems really don't hit that "look and feel" that I want until long after they've evolved naturally...however long that is. Stuff needs to acquire a "patina" of biofilm, a "stain" from the tannins, and decomposition of botanical materials needs to really begin before one of these systems turns "functional" as well.

I mean, every new botanical-style tank looks cool from day one...But the long-established ones stand out. After 6 months, that's when things get really special.

I've long held that my fave botanical-style, blackwater aquarium of all was the one I did about 2 years aquarium utilizing mangrove wood, extensive leaf litter, and catappa bark throughout. This is probably the only tank in recent years that I've truly regretted changing and moving on from! 😂 

It literally looked like shit for the first couple of months of it's existence: Slightly tinted water, a contrived-looking "campfire-like" wood stack, bare sand, and mostly intact botanical materials. I had to do a bunch of iterations with the hardscape to get it where I wanted it. It almost looked contrived, but I knew instinctively that if I waited it out, let Nature do her thing- that the potential was huge in this tank.


Sure enough, a few months in, biofilms started forming. The wood acquired that "patina" we talk about so much. Leaves and botanicals broke down...And the water took on the most earthy-looking, deeply mysterious color I've seen in a blackwater aquarium.

By some standards, the water in the tank could be described as almost "turbid"- taking on an appearance as though there were fine materials in the water column. Yet, the tank had a real magical appearance with the lighting; the fishes were as colorful, relaxed and happy as any I've ever seen, and the water parameters were spot-on and consistent for as long as the tank was set up.

The essence "wabi-sabi", for sure. Transience, the ephemeral aspects of our botanicals...the wonders of Nature, embraced.

I could have "intervened" at a number of junctures- trying to "circumvent" these aesthetic "deviations" while the tank was evolving. However, I knew not to. I knew that the long-term gains from letting this system evolve would far exceed any "relief" I'd gain from siphoning out the biofilms, removing decomposing leaves, and clearing the water.

And, as usual- Nature delivered...because I didn't get in Her way.

We've done this numerous times with similar results.



And then there are aquariums which are simple in concept, look "about right" from day one; and you just need to set them up and sort of "wait it out" until they start looking and functioning in a more "established" manner- which might only take a few weeks or a month or two at the most.

Yet, even in those "compressed" time frames, Nature only asks that we refrain from intervening. You sill have to have faith..


Now, other experimental systems I've played with simply take more time to do their thing and come into their own before you'd really move on. However, they actually are intended for "forced iteration"- a deliberate change to their composition or progression. Indeed, after the initial setup, the "evolved" product looks little like what it started out as.

Of course, these projects may take many months to evolve as part of the plan.

The best examples of this are what I call my "Urban Igapo" tanks- the Varzea aquarium I'm playing with is perhaps the most evolved one that I have pics of at the moment.

Intended from the outset to demonstrate how an ecosystem changes from "dry season" to "wet season", this tank started out in a "terrestrial mode", with a carefully blend of selected substrate materials, mixed with botanical materials, such as crushed leaves, to form a representation of a forest floor. After a period of time sowing some seeds and bulbs of terrestrial plants, the substrate was quite damp and established.

And of course, when it was time to "inundate", the system took on a completely different look and feel, transforming from a purely terrestrial environment to an aquatic one.

The key ingredients: Time and patience, in generous quantities, and having a plan or "track" to run with, create truly interesting outcomes...if, of course, you let them play out without interruption.

My true "igapo" aquarium went on a slightly different track...It started it out in "wet" mode- silty, sedimented, and tinted, and then I "drew down" the water level and sowed grass seeds to take advantage of the wet, rich substrate for growth.

It's in "terrestrial mode" at the moment, happy growing Paspalum grass. Months afterwards, we will begin the process again...and run through the "seasonal cycle" once more.

The timetable governing this process can be "manipulated", but the pace at which things happen- growth of the grasses, establishing them, and how long they survive under inundation- are dictated almost entirely by Nature. We're merely facilitating the process.and watching! 

And then there are systems which, by virtue of their very concept, capture the essence of a natural habitat in a very specific phase- and can do it almost immediately...

An example of an aquarium that takes on the "established" look literally from the first days would be the "Late Season Igapo" tank that we recently set up. This system is designed to replicate- in form and function (to a certain extent, of course) the habitat which emerges when a flooded forest floor is inundated for several months. After this period of time, much of the terrestrial vegetation goes into a "dormant" phase, and detritus and biofilms over a "matrix" of these materials form the basis of the aquatic "terrain."

And of course, utilizing a mix of sediments, crushed leaves, and plant stems/twigs in the scape encourages the formation of biofilms and the sequestering of detritus and other materials as the basis of your scape will, almost from the beginning, give you an established-looking tank which also happens to function in a manner similar to what you'd find in the natural habitat.

This is an aquarium that- much like the leaf-litter-only system that we talked about above- is providing the bulk of the nutritional needs of its resident fishes (in this case, Neon Tetras) with little to no supplemental feeding. The "changes" to this habitat will simply take place at the pace of Nature.

She'll dictate the direction of this tank for the next few months.

Botanical-style aquariums typically require more time to evolve. This process can be "expedited" or manipulated a bit, bit to achieve truly meaningful and beneficial results, you just can't rush stuff! 

You can't interrupt it.

When you do, as we've learned, results can be, well- "different" than they would be if you allow things to continue on at their own pace. Not necessarily "bad"- just not as good as what's possible if you relax and let Nature run Her course without interruption.

Patience is our guideline. Nature our inspiration. Experience and execution our teachers. We're on a share the benefits which can be gained by embracing and meeting Nature as She really is.

Give Her a chance. let's let Nature do her thing without interruption.

Trust me. She's awfully good at it.

Stay observant. Stay diligent. Stay bold...

And Stay Wet.


Scott Fellman

Tannin Aquatics


August 17, 2020


Common threads and functional aesthetics...

I like to look back on some of my favorite tanks over the years, and they have some  interesting commonalities. Generally, these include things like certain elements used in the "operating system" of the aquarium.  Things which operate very similarly to the natural habitats which they aspire to recreate in the aquairum.

What do I mean? Read on!

The idea of biotope aquariums is well-covered territory in the hobby. I really don't need to discuss the whole concept with you. However, the idea of 'biotope" or "biotope-inspired" aquariums should be, in my humble opinion, more than just trying to capture the look of a habitat. The finest biotope-inspired systems foster the function as much as the aesthetics.

And, when we approach recreating some of these habitats from a "function forward" approach, as opposed to just trying to recreate the look, not only do you create interesting "operational parameters", you get many unusual benefits as well- some of which are analogous to those which the natural environment offers to the organisms which reside there. And of course, the aesthetics often look substantially different than what you get when you just go "diorama mode."

One of my favorites is an aquarium that I set up earlier in the year to represent the form and function of a flooded Pantanal grassland. This was a very different interpretation of a very unique ecological system.

For those of you who aren't familiar with it, The Pantanal (derived from the Portuguese word "pantano"- meaning "swamp", "wetland", or "marsh") is the largest wetlands region Earth. Full stop. Primarily located within the Brazilian state of Mato Grosso do Sul, it also extends into the state of Mato Grosso, and the nations of Paraguay and Boliva as well! We're talking about region estimated to be as large as 75,00 square miles/195,000 square kilometers!  

It's freakin' huge! 

Essentially a large depression in the earth's crust, the Pantanal constitutes a huge river delta, into which a number of rivers converge, depositing sediments and other biological materials. Now of course, with a habitat this large, there are multiple ecosystems contained in it- as many as 12 have been defined by scientists! 

(Image by Alicia Yo- used under CC BY-SA 3.0)

Now, our main focus is, of course, fishes- and the Pantanal offers plenty of places for fishes to reside in! The cool thing about the Pantanal is that as much as 80% of it is floodplains submerged during the rainy seasons (in which up to 59inches/1,500mm of rainfall have been recorded! That corresponds to water depths which can fluctuate up to 15'/5 meters in some areas!), and is home to an astonishing diversity of fishes and aquatic plants!

With it's enormous expanse of shallow, slowly-flowing water (velocities of no more than 4"/10cm per second are typical), dense vegetation tends to be the norm here- both aquatic and terrestrial.

The water itself tends to be turbid, very slightly tinted, and perhaps even a bit anoxic at times. And, interestingly, the highest levels of pH and dissolved oxygen in these habitats tend to occur when the water level decreases and aquatic and terrestrial plant growth is stimulated. Curiously, however, scientists are not 100% certain if this is because of the plants going crazy with photosynthesis, or mixing of the water column due to influx of water. 

Is there a takeaway here for hobbyists?

Over 400 fish species call this region home. Interestingly, the biological  "keystone species" of The Pantanal is a snail- the "Apple Snail" (Ampullaridae), which is a real survivor, as it has both gills and lungs, which makes survival possible during the early part of the flood season when huge amounts of terrestrial plants decay and use up the available oxygen, resulting in suffocation to all of the larger decomposers in the ecosystem.

This remarkable- and fortunate- adaptation enables the humble snail to consume the majority of the dead plant matter and turn it into "fertilizer" for the aquatic plants...And, in an ultimate sort of insult, really- the snails eventually become feed for other animals.

A rather undignified end for such important creatures, wouldn't you say? 

(The "keystone species"- image by Stijn Ghesquiere, used under CC BY-SA 3.0)

Many of the fishes which are found in The Pantanal are migratory, moving seasonally between the river channels and the flood plain regions. As you might imagine, the bulk of them are detritovorous, feeding on the fine particles from the accumulated sediments and macrophytes (remember them?) within the ecosystem.

Macrophytes supply shelter, food resources and cover for the resident fishes. Still other fishes consume the aquatic insects and microorganisms/biofilms that are recruited in this habitat. Most are well-adapted to the relatively oxygen-poor waters of this vast flood plain.

Characins are represented big-time in this habitat, with species of Moenkhausia, Hyphessobrycon, Pyrhulina, Aphyocharax, and Characidium all present. Oh, and Apisto lovers will be pleased to know that there are some cool ones found there- Apistogramma borellii, A. trifasciata, A. commbrae, and some others. Even species as wide-ranging and diverse as Corydoras, CrenicichlaOtocinculus, Abramites, and Leporinus are found in this ecosystem.

According to most of the studies I read on this ecosystem, the contributing factors to the fish population include stuff like the clarity of the water, the abundance of the food sources (ie, those macrophytes again!), and the connections between lakes and rivers. And, as the water recedes, the available macrophytes tend to settle on the margins of the habitat in the form of...wait for it...our old friend, detritus! 

There's just too much good stuff here, huh?

And during the low-water seasons, the resident fishes tend to occupy the areas where autochthonous resources- materials which formed in the areas where they are found, not from outside of the habitat a la our old friends, the allochthonous resources. 

(Damn, we talk about some obscure shit in this blog, huh?)

Of course, the seasonal flooding of the marginal lowlands increases the quantity and availability of allochthonous feeding resources for the floodplains and the fishes which reside there. An interesting example of the tight relationship between various habitats in the region, wouldn't you say?

When the water levels rise, the marginal vegetation in the habitats dies off and contributes to the levels of organic matter found in the water. This results in a decrease in dissolved oxygen, pH, and transparency of the water column. Those of you who are geeky hardcore biotope hobbyists, who obsess over stuff like creating a tank to represent a habitat in a specific time of year should take note, huh?

Even the lifestyles of the fishes play a role in the "operating system" of the environment.

Biologists tend to think that the small guys- the characins, specifically, benefit from fast growth, high fecundity (ie; they're prolific!), and rapid colonization capabilities- and that these characteristics tend to determine success in The Pantanal environment. And one more example of this is the "role" of fishes in the Pantanal which consume fruits (which come from the trees adjacent to the wetlands).  Around 150 species of fruit-eating fishes inhabit this system- that's a remarkable number!

When the fishes eat the fruits, they pass the seeds through, well- pooping. Amazingly, it's thought  that they are responsible for the dispersal of as much as 95% of the trees which comprise tropical forests of the region! That's literally the definition of "doing useful shit", IMHO...

This habitat is just FILLED with possibilities for replication!

This relative absence of representation of this habitat in the natural aquarium hobby tells me that not only is The Pantanal ripe for replication- it's a perfect ground-floor opportunity for studying, discovering, and creating evolutions and breakthroughs in the hobby. To work on replicating some of the function of the habitat as well as the form.

Okay, so we touched on that habitat enough to (I hope) whet your appetite to find out a little more and attempt to replicate its form and function in an aquarium!

And that's kind of what we're gonna do. I hope you join us there, too. At the place where what we know and what we think about in the aquarium hobby meet. At that "delta" at the intersection of science and art.

The aquarium that I created to replicate this flooded environment really went together easily... the "ingredients" are readily available...

It starts with a sedimented bottom layer, replete with dried leaves and some terrestrial grasses, maybe some twigs or submerged pieces of dried weeds. That not only helps recreate some of the look, it helps to foster the function as well.

That's the easy part of this whole thing. 

It's hardly "revolutionary" or even crazy...Yet, to attempt to replicate one of these complex natural habitats in the aquarium requires us to look ourselves in the mirror and see if we're up to the challenges (aesthetic and otherwise).

It looks weird. It involves ideas that we've touched on here for years- decomposition, fungi, turbidity, and...mental shifts.

Had enough of this shit? Or, are you thirsty for more?

I submit to you the idea of turbid, sediment-filled tanks, where dead branchy materials, decomposing leaves, twigs, biofilms, clays, soil and silt play...

This type of feature really pushes us out of our comfort zone.

You have silty, sedimented material which, when disturbed, will cloud the water a bit for days at a time. Sort of like what happens in Nature- but it's in your living room.

Could you handle this?

What's the "upside" to a tank like this?

Well, for one thing, you have the benefit of a substrate which actively leaches minerals, organic materials, and other compounds into the aquarium.  It also fosters  the growth and proliferation of fungi, bacteria, and microorganisms, which not only facilitate processing of dissolved organics, but serve as a supplemental food sources for our fishes.

In my 'late season Panatanal" tank, the water quality was great. I had nitrate levels which were almost undetectable, despite the presence of large quantities of decomposing leaves and other materials. And the need to heavily feed my fishes which resided in the aquarium was not that great. They continuously derived supplemental nutrition from the aquarium itself, similar to the "leaf litter only" system I ran a while back with great success.

This is extremely similar to the benefits which flooded grasslands and such provide in Nature.

"Common threads", indeed! 

And of course, it looks totally unique, too.

It's a very different type of "aesthetic beauty" than we are used to. It's an elegant, remarkably complex microhabitat which is host to an enormous variety of life forms.  And it's a radical departure from our normal interpretation of how a tank should look. It challenges us, not only aesthetically- it challenges us to appreciate the function it can provide if we let it.

"Functional aesthetics." Again.

One of the things that we've noticed lately in the hobby, particularly in our sector, is a trend towards more "realistic" aquariums. Not just systems which look like natural environments; rather, systems which are modeled as much after the function of them as the aesthetics.

"Functional aesthetics."

The aquarium looks a certain way because of its function.

A less rigidly aesthetically-controlled, perhaps less "high-concept" approach in the eyes of some- setting the stage for...Nature- to do what She's done for eons without doing as much to "help it along." Rather, the mindset here is to allow nature to take it's course, and to embrace the breakdown of materials, the biofilms, the decay...and rejoice in the ever-changing aesthetic and functional aspects of a natural aquatic system- "warts and all" -and how they can positively affect our fishes.

We're seeing that not only do botanicals, leaves, and alternative substrate materials look interesting- they provide a physiological basis for creating unique environmental conditions for our fishes and plants. We're seeing fish graze on the life forms which live in and among the decomposing botanicals, as well as the botanicals themselves- just like in nature...And we are seeing the influence- aesthetically and chemically- that these materials assert on the aquarium's environmental parameters.

Some of the "next" things that I see our community working on are further explorations into understanding and replicating natural water parameters and what the implications are for our aquariums. I also see more developments in trying to recreate some aspects of natural "food chains" in our BWBS aquariums, by facilitating the growth and reproduction of fungi, microorganisms, and small crustaceans within our botanical "beds" and leaf litter.

It's about expectations and understanding. If you're just looking for a cool aesthetic, that's okay. You simply need to understand what happens to botanicals when they are submerged in they break down, what they do to the appearance and environmental parameters of our tanks. 

It's the era of "Functional Aesthetics"- and yeah, you're right in the thick of things.

The common threads which connect these aquariums is their emphasis of form versus function. Sort of like, "if you set up the tank to work a certain way, it'll look different, too!" 

And with Nature as our guide, we've got a pretty good track to run on!

Stay inspired. Stay excited. Stay busy. Stay engaged. Stay creative...

And Stay Wet.


Scott Fellman

Tannin Aquatics


August 14, 2020


Celebrating the journey...

We've been about 5 years now into our mission of elevating and educating the aquarium hobby community about the joys, benefits, and challenges of botanical-style, blackwater/brackish water aquariums. We've touched on a lot of topics- ranging from big picture stuff to the extremely arcane.

I think we've done a pretty good job at spreading the word.

However, there is something that I keep coming back to. An idea that keeps popping into my head after numerous discussions with other hobbyists, seeing the evolving "market segment" for botanicals, and just answering lots of questions regularly:

I think that we- as a hobby, are not doing a good enough job celebrating the process of creating aquariums.

I think we celebrate the “finished product” and fail to celebrate the joy, the heartache, the time- and the patience- the journey-which go into an aquarium. And further, I don't think we as a hobby do enough to recognize the telltale signs of hobbyists going too fucking fast..

And we continue to coddle stupid behavior (yeah, I said it) by not instructing newcomers to do some of the research themselves, rather than plunge ahead blindly, only to ask specific questions when something goes wrong.

If you frequent various hobby forums or Facebook groups, you’ll see evidence of this issue all over the place. And I’m not the only one who has been noticing this, as evidenced by the considerable number of dm’s and emails I receive, and, the discussions I’ve had with other hobbyists on the subject.

A lot of hobbyists want to "not be bothered" with the details or background education, and just jump into the game without any effort to educate themselves or do some of the homework required. It's apparently far easier to just look at pictures, go the the LFS or online vendor and buy a bunch of stuff, set up the tank, and see what happens.

Okay, we do have “build threads”, which are pretty cool and often inspiring, I think! We at least facilitate the sharing of the process of building aquairums. They’re pretty popular, as they are inuring, interesting, and for many- aspirational.

While the bulk of them do just that- celebrate the process- a disturbing number of them seem to exude an underlying feeling of “impatience”- a sense that there is a “destination” to get to- and that the person posting wants to get there really quickly! And I get this sense when I talk or correspond with some hobbyists, too. I see these types of “dysfunctional” (for want of a better word) build threads in reef keeping forums constantly, and they follow a very predictable path:

They start out innocently- and excitingly enough- the tank concept is highlighted, the acquisition of (usually expensive) equipment is documented, and the build begins. The pace quickens. The urgency to “get the livestock in the tank asap” is palpable. Soon, pretty large chunks of change are dropped on some of the most trendy, expensive coral frags- or worse yet- whole colonies- available.


Everyone “oohs and ahhs” over the additions. Those who understand the processes involved- and really think about it- begin to realize that this thing is going too fast…that the process is being rushed…that shortcuts and “hacks” are cherished more than the natural processes required for long-term success. Sure enough, within a month or so, frantic social media and forum posts are written by the builder, asking for help to figure out what his/her expensive corals are “struggling”, despite the large amount of cash spent on high-tech equipment and said corals from reputable vendors.

When suggestions are offered by members of the community, usually they’re about correcting some aspect of the nitrogen cycle or other critical biological function that was bypassed or downplayed by the aquarist. Usually, the “fixes” involve “doubling back” and spending more time to “re-boot” and do things more slowly. To let the system sort of evolve (oh- THAT word!) The “Yeah, I know, but..” type of responses- the ones that deflect responsibility- start piling up from the hobbyist.

Often, the tank owner will apply some misplaced blame to the equipment manufacturer, the livestock vendor, the LFS employee…almost anyone but himself/herself. Then, the hobbyist goes "radio silent" for a while...And soon after, the next post is in the forum’s “For Sale” section, selling off components of a once-ambitious aquarium.

Another hobbyist lost to lack of patience.


The single most important thing you need for a successful raquairum (well, except maybe cash!)- and the thing we celebrate the least, IMHO. And we should celebrate it a lot more.

Because you really can’t skip the process…

Well, we can speed up some processes by adding bacterial additives to our new aquariums to “jump start” the nitrogen cycle. We can utilize specialized soils and additives to help give aquatic plants the nutrition they need from day one. We can densely plant. All of these things and more are ways we have developed to speed up the natural processes which occur in our aquariums over time.

They are band aids, props- quick starts…”hacks”, if you will.  All of them can work as part of a comprehensive process. However, they are not the key to establishing a successful long-term-viable aquarium in and of themselves. Ultimately, Nature has to “sign off” on, and work with any of the “boosts” we offer.


It’s a problem, IMHO.

It doesn’t apply to everyone- it’s not always a devastating ending. However, it happens often enough to affect the hobby as a whole, especially when someone drops out because they went in with unrealistic expectations brought about by the observations they make every time they open up their iPad.

The problem is, we as a hobby love to highlight the finished product above almost all else.

We document and celebrate the beauty of the IAPLC champion’s ‘scape. But we minimally document the process that it took to get there. The reality is that the journey to the so-called “finished product” is really every bit as interesting as the finished product itself!

It’s where the magic lies. The process. The journey. The time. The evolution. The patience.

I’ve always found it somewhat odd to see those amazing "high-concept" planted tanks broken down in their prime by the owner, to start a new one. I guess it’s part of the culture of that niche…a sort of self-imposed “termination” when something new is desired.  And I think it's part of the "contest mindset", too. The “process” is about hitting certain benchmarks and moving on, I suppose. (and if you only have one tank and 500 ideas, and the goal is to enter it into a new contest, it makes sense)

And we have to respect that.

However, that's great for the contest guys, right?

Yet, we also have a duty to explain this to newcomers. We have to let people know that, even in one of those seemingly “temporary” displays, patience and the passage of time are required.

Sure, these aspects don’t make for the best “optics”, as they say in politics. You can’t show an empty, cloudy aquarium on Instagram or Facebook and get 400 “likes” on the pic. No one wants to see the results of 33 consecutive nitrite tests.

It’s not sexy.

Sadly, acceptance from others of how cool our tanks are is a big deal for many, so sharing an “under construction” tank is not as exciting for a lot of people, because we celebrate that “finished product” (whatever it is) more than the process of getting there. We simply need to celebrate patience, the journey, and the “evolution” of our aquariums more.

After a lifetime in the hobby it’s pretty easy for a guy like me to see when things are going in a direction that may not give the happy outcome my fellow hobbyists want. I see this just as much in the freshwater world as I do in the reef world.

I see this after some of the "contest giveaways" and club raffles we support. A high percentage of the time (not always, of course), the winner, who receives a package of botanicals or whatever, seems to be the least informed, about this speciality, and often not really all that interested in doing the research before plunging forward. I mean, it's just adding some hardscape to a tank, right?

They just want one of those cool "blackwater aquariums" that seem to be all the rage on Instagram these days. It's a "cool style of aquascaping", right?

It makes me cringe, really...and to question the wisdom of just giving stuff away sometimes. Lack of desire to take the time to educate one's self, and lack of willingness to deploy  patience about the process is almost rampant when it comes to this stuff.

It's all about the finished product.

The questions I receive from some of these people reflect this. There is simply no effort to learn about the process or the expectations, etc., despite reference to a lot of resources on line- here and elsewhere.  A lot of these people simply see the pretty pictures of finished tanks, and are excited to receive a pack of "aquascpaing stuff" for their tank and create one. Quickly.

I cringe, because I know that failure to educate oneself before plunging forward adding botanicals to an established tank without consideration for what they do can be a disaster.

And with concerns about the growth of the hobby always brought up in gatherings and discussions, I think we owe it to ourselves to look at this more seriously; to think about the impact of this stuff on “big picture” a bit more.

Think about this:

Part of the reason why we celebrate the “evolution” of reef tanks is because the very act of working with one of these tanks IS an evolution. A process. A celebration of sensory delights.

A reef aquarium has a “cadence” of its own, which we can set up- but we must let nature dictate the timing and sequencing. It starts with an empty tank. Then, the mixing of saltwater, the addition of live rock and sand…The excitement of the initial placement of the rocks within the tank. The gradual “addition of the corals. The progressive development of biofilms and algae “patinas”. Ultimately, the growth of the corals and associated fauna. All part of a process which can’t be “hacked” or rushed.

Mother Nature is in control.

Whitby 01-01.jpg

Reefers who try to cheat, "hack", or rush the process often become "ex-reefers" really fast. Nature will simply kick your ass- and quickly.

Or, they wipe themselves off and start over again, perhaps better educated for having gone through the resulting disasters which ensue when patience is thrown out the window.

We need to stress the process as much as the “finished product” (whatever that might be, in this instance). I constantly talk about this, I know, but it’s really fundamental, IMHO. And it would be easy to describe my concern as very opinionated (well, it probably is…), and perhaps, a bit "asshole-ish" but if you look at it objectively, it’s worth considering.

We see people come into the hobby with some expectations of how they want their own aquarium to look, based on the tanks they see on forums and elsewhere. Human nature. Nothing wrong with having aspirational tanks to challenge us and inspire us. Yet, we really need to stress the aesthetics of the tank during the “evolution” as part of the function, too.

We should celebrate biofilms, fungal growth and the growth and die off of some plants. It’s the very essence of Amano’s interpretation of Wabi-Sabi- the celebration of the transient nature of existence.

We should.

But we don't always.

And I get it.

Not everyone appreciates the “zen-like” mindset I think is required to truly enjoy a botanical-style aquarium like this. Not everyone finds the biofilms and decomposing leaves on the substrate alluring. The fact that it closely replicates the natural ecosystems we love is of little consequence for the hobbyist who dislikes the heavy growth of various fauna and such, and wants a more “artistic” look to his/her tank, or a way to display his expensive "designer wood".

And that’s okay. 

Now, it's not all "doom and gloom" or negative energy. Really.

Most of us who play with botanical-style aquariums DO celebrate the process. The evolution. Savor the time it takes to see a tank mature in this fashion. We love new tanks, just starting the journey, because we know how they progress if they are left to do what Nature wants them to do. We understand as a community that it takes time.
It takes patience.
And we celebrate that the evolution is the part of the experience that we can savor most of all…because it’s continuous.


And we can reverse this unfortunate trend. 

As a hobby in general, we need to document and celebrate the process. Let's share more "early and 
unglamorous" progress pics of our tanks on Instagram. Let's celebrate the journey!

We need to have faith in Nature, and relish the constant change, slow and indifferent to our needs though it may be. We need to emphasis to new and old aquarists alike that, in this 24/7/365 social media-fueled world we’re in- that patience, time, and evolution are all part of the enjoyment of the aquarium hobby.

All of the aspects of the process are wonderful:

The smell of a brand new tank. The delight at the first new piece of wood or leaves added. The addition of the first fishes. All are experiences on a road -a journey- which will forever continue. As long as we allow the processes which enable it to do so. 

As long as we celebrate the journey.

The long-term health of our fishes- and the hobby itself- demand it.

Be kind to yourself. Be good to the hobby. Document. Share. Savor the process.

Stay patient. Stay generous. Stay honest. Stay curious.

And Stay Wet.

August 13, 2020


Back to the past via the future: The evolved reef tank? My new take on things...

As most of you know by now, I started Tannin Aquatics after decades of serious hobby and professional work in the Marien side of the hobby- specifically the reef  aquarium sector. Although I started in the freshwater side of the hobby, I "crossed over" to more fo a full-time marine hobbyist as a teenager and didn't look back seriously until about 5 years ago, when I started Tannin. 

With Tannin, we took a different approach to freshwater aquariums- one based on embracing natural botanical materials to more faithfully replicate the look and function of specialized aquatic habitats, such as blackwater and brackish. I drew from my long experience at playing with this stuff , and felt that if I liked it, maybe some other hobbyists would, too.

I think I guessed right this time!

It's been an interesting Gand exciting 5 years, filled with a lot of cool developments, evolutions, and the occasional breakthrough. Along with you, our community, I've learned quite a bit, and I'm looking forward to some more cool experimentation.

Of course, I never fully got over my reef addiction, too...

Which  brings me to the topic of today's blog. Recently, a follower of ours on Instagram asked me to share some thoughts about how I'd set up a marine aquarium today. It's an interesting idea, because although my interests in the reef sector remain similar to what they were 5 years ago, my experience in the botanical-style freshwater and brackish sector with Tannin has given me a different perspective than I had previously, and I think I'll be doing things slightly differently on my next "full salt" go-around!

So, like, how?


My stated goal is to create a modest-sized aquarium that embraces natural processes which occur in various niches within the reef biome. Now, that being said, I am interested in more of a lagoon-type habitat, preferably one with a strong connection to the nearby land. I am fascinated about the idea of incorporating mud, biosediment, and other substrate materials into the display. 

I know that this comes as a shock to those of you who are familiar with my obsessions! The idea of re-creating a little habitat around a mangrove tree and some seagrass, or to attempt to replicate those “coral islands” in Palau (reef below, terrestrial plants above) has been tugging at me for decades…and I think it might be time to play with one of these concepts.

High biodiversity is my thinking here.



Yes, you’ve heard me yammer about it, but I’m still really into the idea of using various types of ocean-sourced muds and sediments in reef aquariums. This is not exactly new. It’s something we've played with over the past few decades, right?  And the idea of substrates and their accompanying nutrients and diverse infauna has fallen largely out of favor in the general reef hobby of late.

Yet, with all of the ideas of sandbeds and such, I think we should be utilizing natural mud, or the really great substrates offered by a number of aquarium companies. Now, I’m not talking about using these products because of some over-blown marketing hyperbole about them curing sick fishes and raising corals from the dead or whatever. Nope.I'm talking about utilizing them because they foster biodiversity.

I’m curious about the way these materials can impart trace elements into the water. I’m curious how they foster denitrification. I’m very interested in the possibility of them providing supplemental nutrition for a wide variety of fishes (specifically fishes like Halichoeres sp. Wrasses, Ctenochaetus sp. Tangs, and Pseduchromids, just to name a very few.). And I’m almost obsessed with the possibility that they can serve as an "in-tank refugium" (well,sorta) for cultivation of organisms which might serve as supplementary food sources for most of the fishes and higher invertebrates in our systems.

Very "early 21st century, I know....

Mud was one of those odd tangents that hit right around the “early 2000’s refugium craze", and sort of faded quickly into the background. I am sure that part of it was a renewed obsession later in the decade with less biodiverse, more “coral-centric” systems, which eschewed substrates in general, specifically those which had the tendency to house competing biota! All of those factors- and a continued (and cool, I might add) obsession with using high tech electronic pumps to facilitate ridiculous amounts of water movement within our aquariums sealed the fate of mud as a true reef “side show” for the foreseeable future.


Well, here we are, in the 2nd decade of the new millennium, and I think that it’s time to resuscitate the idea of using mud in our reef tanks again in some capacity. And I’m thinking not JUST the refugium. I’m talking about the display! Now, I realize that a lot of reefers will disagree with my thinking, and give me the usual line that sand and mud and sediment can become “nutrient sinks” and work against the smooth operation and long term prosperity of a reef. 

Okay, I hate that shit.

And that's what it is. I know this, because I play with decomposing leaves, sediments, and biofilms. I'm not afraid of high biodiversity, higher nutrient systems. They run amazingly well if you are competent about husbandry, if you're observant, diligent, and patient. So I think it might be worth looking at how a well-managed mud/sediment/sand bed could help support a healthy, diverse closed reef ecosystem.

Now, if you go way back into the past (like 2005, lol), you may recall some of the studies into various substrate depths and compositions (and plenums!) and their relative impact on mortality of animals in aquaria. Now, in all fairness, the test subjects were fishes and inverts like hermit crabs and snails, but the findings are nonetheless relatable, in my opinion, to reef tanks. Tonnen and Wee ran a lot of tests with different depths of substrate, ranging from very deep to rather deep, and the results were quite fascinating, in my opinion. Interestingly, one conclusion was that “...the shallower the sediment, the higher the mortality rate, and you can't get much shallower than a bare-bottom tank!"

WTF? I thought "bare bottom" was the shit... 😆

Again, that set of experiments had a lot of different variables, like the aforementioned plenum, as well as the use of pretty coarse substrate in some setups (Not too many reef hobbyists use that stuff!), and no real test using marine muds and sediments as the sole substrate in a reef setting. However, I think it is perhaps safe to say that the presence of a substrate itself in a reef tank doesn’t spell disaster for the inhabitants- be they fish, corals, or urchins…The reality is that a well-managed, carefully stocked reef tank should work under a variety of situations.

And of course, the cautions are warranted.

A poorly maintained sandbed, without some creatures present to stir up the upper layers, could prove problematic if detritus and organic wastes are allowed to accumulate unchecked, right? And there is the so-called “old tank syndrome” that suggests that after some point in a reef systems operational lifetime (whatever that might be!) the bacteria population within the system (likely the sanded) is depleted somehow and/or no longer has the ability to keep up with the accumulations of organic waste products, and that phosphates and such are released back into the system.

Also, a lot of horseshit, IMHO. There are plenty of "old reef tanks" out there that run beautifully.

Yeah, I'm probably being a jerk, and simply being biased, but I have a real problem with that theory. I just don’t see how a well-managed aquarium declines on its own  over the years. I’ve personally maintained one reef tank for 11 years, and one freshwater tank for 16 years and never had these issues. I’m not saying to nominate me for sainthood or anything, but I will tell you that I am a firm believer in not overstocking my tanks, utilizing multiple nutrient export avenues (protein skimming, activated carbon, use of macro algae/plants, and weekly water exchanges).

There is no magic there.

So, yeah...sandbeds, mud, sediments...they're all cool in my book.

Okay, that being said, tanks with substrate, specifically fine sediment materials like mud and such, are not “set and forget” systems. You’ll need to be actively involved. And by “actively involved”, I mean more than tweaking the lighting settings on your LEDS via your iPhone 😆. You’ll need to get your hands wet. Which to me, is the best part of reef keeping!

Now, I’m literally just scratching the surface here, deliberately not going too deep into this because I’d like your thoughts and input. However, I think it’s absolutely possible to maintain a successful reef system with mud and other marine sediments as a significant part of the substrate. One of the keys, in my opinion, is to utilize some marine plants…you know- seagrasses.

Yep- thats’ a whole different story for another time, but I will dutifully touch on them here to open things up more. I think they are deserving of more attention from reefers. And freshwater planted people have a real advantage here to help move interest in seagrasses into the hobby limelight, where they belong.


Okay, we all have probably seen or heard about seagrasses at one time or another, but rarely do we find ourselves actually playing with them! They are not at all rare in the wild- In fact, they are found all over the world, and there are more than 60 species known to science. Seagrass beds provide amazing benefits to coral reef ecosystems, such as protection from sedimentation, a “nursery” for larval fishes, and a feeding ground for many adult fishes.. In the aquarium, they can perform many of the same functions.

If you can provide a mature, rich sand bed (say 3”-6”), good quality lighting (daylight spectrum or 10k work well), decent water quality, and no large populations of harsh herbivorous fishes, like Tangs or Rabbitfishes), you can almost guarantee some success with seagrasses. And the other key ingredient is patience. You need to leave them alone, let them acclimate, and allow them to grow on their own.

Patience. A key ingredient that we're all sort of familiar with by now, right?

By the way, you can use a variety of commercially-available substrate materials in addition to your fish-poop-filled sand that are designed just for this purpose! How ironic- products actually exist to help grow seagrasses, and so few people are actually taking advantage of them! Oh, and wait, a well-stocked reef is also capable of creating a good rich sand bed, huh?


Seagrasses offer just another interesting diversion and an opportunity for the hobbyists to try something altogether new in the reef aquarium. Not only will you be growing something cool and exciting, you’ll have a chance to get in on the ground floor of a new area of the marine hobby. Does that sound sort of familiar?

By unlocking the secrets of seagrasses, you will be further contributing to the body of knowledge of the husbandry of these plants. Obviously, I just scratched the uppermost surface of the topic here, but I’m hopeful that I have piqued your interest enough to investigate and give the seagrasses a try!


It’s my opinion that the key to a high biodiversity reef tank in the long term would be to incorporate these true vascular plants into the mix. And mangroves, too! You've seen us do a lot of work with our "Estuary" stuff for Tannin- and the brackish water mangrove tank we've played with. We embraced a completely different version of a brackish tank: One filled with mud, decomposing leaves, infernal crustaceans, and diversity.

Mangroves create an amazing aquarium ecosystem.

Now, I would be fooling myself and all of you if I felt that a mangrove pant in your reef tank is going to contribute in any meaningful way to nutrient export for your system. This is a common "selling point" that some people use for utilizing mangroves in reef tanks...and it's really a weak one, IMHO.  Sure, they may pull some nutrient from the water or substrate, but their real value, in my opinion, is to foster the growth of epiphytic life (diatoms, tunicates, etc.) which contribute to the nutrient export and biodiversity of the aquarium.


And of course, they look cool.

And I am very fascinated about playing with mangroves leaves, and the decomposing materials and how they interplay with the aforementioned sediments, and corals…There’s a lot going on there. It’s a lot to consider for a reef tank…but I can’t help but feel that there is something to be gained by incorporating mangroves into the mix…I have visited author/aquarist Julian Sprung’s unique and highly diverse reef systems several times, and each time I’m taken with just how well everything functions as part of a whole- plants, macroalgae, seagrass, sponges, tunicates, feather dusters, coral, invertebrates…fishes. Real deal diversity. Truly the "reef as a microcosm" idea that author John Tullock outlined so many years ago in his writings.



As the leaves fall into the water, if allowed to decompose (ohh…WOULD you do that? I would- but you kind of know that already...), can foster the growth of significant populations of microorganisms and small crustaceans…the literal base of a “food web” in our tanks. Can you imagine a better aquarium system for hard-to feed fishes, like Dragonets, Pipefishes, Seahorses, etc.? In fact, a cool thing about a tank like this is that you could probably manage it effectively with water exchanges and minimal protein skimming…Allowing some nutrient to accumulate within the system for the expressed purposes of feeding the micro algae and population of small organisms which “power” this small ecosystem.

I’m a firm believer that people like Julian and others are successful with their diverse systems over the long term because they understand and appreciate the biodiversity, and provide conditions which allow the largest majority of life forms to prosper for the longest period of time. Also, these guys have made the “mental shift” that those of you who follow my writing here me speak of so often…The mental shift that understands and appreciates the way these systems actually look.

A POV that realizes that some algae, some detritus, and some nitrate/phosphate is not only inevitable- it’s desirable. It’s a mode of thinking which gets away from the “Coral is everything and the tank must be spotless, with every technical prop used to assure this…” and embraces a mindset of “The tank must be lush and diverse, with a wide variety of animals thriving as they do in nature in a stable environment.”

Two perfectly valid mindsets, with somewhat similar goals, but dramatically different approaches to get there, and viewpoints as to which aesthetic is most attractive. I never quite let go of the "higher diversity approach", and I think it's a compelling way to ru na reef system for many. 

I am not saying that those interested in a more diverse reef system need to ditch all of our high tech gear and go back to trickle filters, 5,000k halides, and massive pump-powered protein skimmers. What I am suggesting is that we utilize the technology and information that is available today and apply it to some of the more interesting approaches from the past which foster more diverse reef systems.

The time has never been more appropriate. Time to look at some of these “niche” ideas with a new mindset- and a new appreciation for what they can accomplish!

And of course, as always.. utilizing technology to not only help us manage systems better, but to help create more realistic representations of the specific characteristics of this habitat. There has never been a better time to re-visit some older ideas than now- with an access to amazing technology and an array of experience that abounds in the ever-expanding reef community. I think it's really a super time for us to examine niche biotope reef aquariums! There is ample room for study, interpretation…and creativity.

We sort of opened the door back in 2017 with the debut of our "Estuary" stuff for brackish tanks...getting you in touch with a saltier side.Since then, we've seen a lot more interest in brackish- and that's the "gateway" to reefs, IMHO. We'll do more to build up "Estuary" in 2021, to encourage further experimentation.

Hopefully, that might lead a few of you to go "all the way" to 1.025! 

(Blast from the past! Remember this one?)

I leave you with a great quote from Steve jobs on the creative process, which might just get you started:

"Creativity is just connecting things. When you ask creative people how they did something they feel a little guilty because they didn't really do it, they just saw something. It seemed obvious to them after awhile.”

Well said.

So, I know I got a bit long-winded; however, that's kind of where I'm going with MY next reef tank: DIversity. Richness...Mud.

Discuss. Dream. Scheme. Execute.

 Stay creative. Stay resourceful. Stay bold. Stay observant. Stay patient...

And Stay Wet.


Scott Fellman

Tannin Aquatics