April 18, 2019


The art of habitat representation: A case study...

As an observer of modern aquascaping- in a variety of forms, I've spent quite a bit of time looking at flooded forest floors. This interesting habitat offers incredibly interesting aesthetics and function. It's a habitat which gives us the opportunity to not only be creative, but to learn about its unique dynamics and function.

If we look at this habitat a little deeper, we can perhaps pull out some components of it, and consider what materials we could use to replicate its unique features. This is something that I love...assessing which materials would do the job. We have received so many requests about "...which ones do I use?" that it made a lot of sense for us to address this in terms of what we offer. Now, I realize that part of the fun is assessing and scheming and curating for yourself; however, we can't help but push a few ideas into your head to perhaps speed along your process!

Now, we've talked about flooded forest floors many times, but not in this specific context.

What would be some "cornerstone" materials that you'd use to represent this habitat? Well, let's break it down:

First, a forest floor has soil. It's sort of a "dirty" place (pun kind of intended...).

In our case, we could use a combination of standard aquarium substrates, like sand, perhaps combined with terrestrial soils, or planted aquarium soils. In one of my recent aquariums, I utilized a fine aquarium sand, coupled with some ground-up, clay-based  aquatic plant soil (Ultum Nature Systems "Control Soil). I selected this material because the aesthetic and grain size, when combined, creates something that looks very much like the soils you'd find on a tropical forest floor.

And of course, no flooded forest floor would be complete without roots, branches, and stems. My recommendations from our "portfolio" would be one of more of the following: Oak Twigs, Senggani Root, or even "Spider Wood." Each brings its own aesthetic and function to the aquarium representation of this habitat.

You could keep the "roots and twigs" to a minimum, placed in a "flat" configuration on the substrate, or let some of them creep up into the "vertical", consuming a bit of the negative space in the aquarium. If you're using materials like the Senggani Root", there is the option of orienting them in a variety of ways. You could even cut up and utilize "bits and pieces" of these materials in lots of different ways, in order to represent that element of the habitat.

The other, and perhaps, most obvious component of this habitat is leaves. Whenever you have trees overhead, you're pretty much guaranteed to have lea yes failing to, and accumulating on the forest floor. And of course, when the waters arrive, the leaves become a dominant part of the newly aquatic habitat.

As you know, we're really into leaves, and we have a pretty good variety of different leaves available. It's really about what you like, the aesthetic you're looking to achieve, and the "scale" of the aquarium.

And of course, seed pods are perfect to use in this type of representation. Some of my personal faves would be smaller items, like Mokha Pods, Calotropis Pods, Dregea Pods, and Jacaranda Pods.  Obviously, the choices are endless. I like these particular materials because they have varying degrees of durability, offer a diversity of shapes, and are of a "scale" that can work even in a smaller aquarium.

And of course, there are other possibilities to replicate this habitat. You can utilize larger materials which represent tree trunks and other large, buttressing structures which end up on the first floor. Larger pieces of driftwood, such as our "Malaysian Driftwood" and "Asian Driftwood," can represent these materials in a most effective way. If you can source  very thick, substantial pieces to represent a tree trunk, either in the "upright" or "fallen" condition.

And then, there are those other materials- such as bark pieces; specifically, Red Mangrove Bark, which comes in larger, more "workable" sizes. Bark not only adds compounds like humic substances and tannins to the water, it creates a rather durable substrate upon which various microorganisms and fungi can anchor and proliferate- adding to the "functional" aspects of the aquarium habitat.

One additional component that you will find on a flooded forest floor would be terrestrial grasses. Many of the grasses in these forests are durable enough to survive these periods of inundation.

Now, we may not have access to the exact species of grasses that are found in these habitats (although you can do some research in academic papers online and find them); however, we can find some species which are representative of them. We could even utilize riparian plants- or perhaps even some aquatic plants (gulp), like Sagittaria, which can really work. Again, it's about representing- as opposed to strictly replicating- components of this habitat.

At the end of the day, about the best we can do is present to you some aspects of the habitat, and recommend some of the materials that you can use to recreate it- or aspects of it- in your home aquarium. And of course, there are numerous other materials you can use from our selections, or materials that you can collect yourself. The art and science of natural aquarium keeping is an evolving and enjoyable one!

And with that...

Stay interested. Stay creative. Stay observant. Stay diligent...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

April 17, 2019


Shout it out...

The aquarium hobby is really overdue for a prolonged "shakedown", IMHO.


We need to change some stuff up. We need to not be afraid to try some new things; push the limits of what is considered "conventional hobby wisdom"- and have the courage to share our ideas; our work. I think we need to take more risks in the hobby. We should try some things which challenge what is comfortable- not just because "they" say you can't- rather, because there is always room for improvement.


You can always do something a bit differently... Wouldn't it be amazing to do something that, although seemingly innocuous and relatively unimportant in the grand scheme of life...would irritate, agitate, and maybe turn some people against you in the part of the hobby in which you engage if you said something?


Could you do this? Would you?


If so, you're downright heroic to me. Really. People don't do this enough.

I see some of you doing this in the hobby right now. Perhaps, too quietly, though. You're doing some crazy shit:

You're doing stuff like creating pure hardscapes that don't follow a "Japanese garden-type" formula. You're playing with "semi-palludariums", minimalist sand and rubble-only scapes. Mangroves. Monospecific planted tanks. Blackwater, botanical style tanks. Biotope-inspired displays. Modern, spawning-oriented species tanks. Cave aquariums. Food-producing "refugium" concept tanks. Just, different stuff.

You are the true "outliers."

What, exactly is an "outlier?"

out·li·er (outˌlīər) - noun- A person or thing situated away or detached from the main body or system. A person or thing differing from all other members of a particular group or set.

It might be you?


You're bit outside of the hobby mainstream, aren't you?

This is important territory that you're playing in. 

It's the realm of the "discomfort zone."

And most of you hobbyists who work this magical place don't generally give a damn about "winning" contests or being "Insta-famous." You know that you likely won't, because you're doing stuff that not everyone gets, or thinks is "cool." Stuff that goes decidedly against the grain of what's "acceptable" or "popular." You're just doing your thing...occasionally showing up and seeing your work create a "disruption"- although it's typically an unintentional by-product of being unique in a stable space, and perhaps not your sole intent.

Yet, maybe you're inspiring someone else...

Yes, I'm fascinated by outliers.  

And what's weird is that there are a fair amount of them out there. Quietly doing what they do; occasionally popping up on the radar, perhaps garnering a curious peek by the "establishment", before retiring back into to the shadows.

There are a lot of supremely talented people in the aquascaping world, for example. 

Yet, I am thinking about someone really different. 

Although, I wondered, would bringing such a person's work to light "corrupt" the real "soul" of what we're talking about? Create a giant, obnoxious hypocrisy of sorts?

I don't know. I don't claim to have the answers. But I don't think so. The aquarium world needs an injection of the unusual right now, in my opinion. And it needs special type of person to do it.

I think it might be YOU.

An outlier. 

Someone who gets it. Someone who's not only not afraid of going against the prevailing trends...a person who simply does their own thing because it gets them excited. Fearless. Not afraid to face criticism from those who don't get it, like it, or appreciate it. The kid who wore black all through high school; maybe seemed a bit "weird" to others who didn't understand him/her.

I've always had this vision of supporting an aquarist who feels something deeper...Finding a person who has a unique dynamic. An artist? Sure. A poet. Sure.  A surfer? Possibly. A writer? Maybe. A "sage?" I don't know. An "old soul." A musician.

Perhaps even a philosopher, of sorts.

Someone who brings something different to the homogenized, prepackaged, neatly ordered aquarium world. Someone who can talk emotionally to you for a very long time about the 5-gallon hardscape aquarium they just created...and leaves you wanting to hear more.

Someone with a deep passion. A spark.

A very different orientation. Someone who asks "Why?" Someone who wants to make a little "noise", not just to be a pain- rather, because they care about pushing the boundaries of "conventional" thinking and expression in the aquatic world. Someone who looks at things from a totally different angle.  Not to "be cool", mind you. Simply because that's how they look at stuff. A person who feels that his/her work is not just a creative expression, but an instrument of change. 

And one who's not afraid to shout it out.

Just because it's time for one.

The hobby, in my opinion, needs such a person. Maybe someone who simply needs their voice to be amplified...


Who is that person? Where is that person? Are there more? 

I'll keep asking. I'll keep looking.

Stay passionate. Stay honest to your vision. Stay humble. Stay unique. Stay diligent. Stay generous...

And Stay Wet.


Scott Fellman

Tannin Aquatics

April 16, 2019


Lost in romance...

As you probably know by now, I've never been one to hod back on expressing how I feel about aquarium hobby topics. Occasionally, I get these little realizations that I like to share with you. And the beautify of having ga blog of your own is that you have no "editor" to say, "Dude, this idea isn't fully thought out...!" or "Are you sure that's what you mean?"

Like, no filter. No safety net. Put the idea out and either people skewer you for it, or it touches them in some way. 

Today, I'm discussing an idea that's been formulating in my mind for a while. I hope I'm articulating it in a way that get's you thinking...encourages instead of provokes; sounds positive instead of negative...but you never know. So here goes:

Lately, I've been receiving a lot of emails and DM's from hobbyists who are in the process of planning an aquarium around a very specific concept or theme, and the ideas I'm seeing and hearing about are truly inspiring. 

Sure, hobbyists have been coming to me with ideas about cool displays for as long as Tannin Aquatics has been around. Yet, this is different. We've had several years of hobbyists trying out these "twigs and nuts", learning about how they impact aquariums, grasping the aesthetics, the processes, and making the mental shifts required for success...and now, they're out of the "Does this work?" or "Can I handle this look?" phase, and evolving towards a "How can I utilize natural materials to execute this next idea I have?" mindset.

This is huge. Different. A shift.

It's sort of an act of pursuing a botanical-style aquarium concept to its logical ends to see how to create something they've had in their heads for a while. There's that, "Ahah! I can use_________ to recreate that_________ I've been looking at!"

I love it.

Now, it's not like the idea of planning an aquarium is this new concept. However, the idea of looking at a habitat or type of aquarium approach and considering how to apply the abundance of interesting natural materials we have available to the project we're working on has, I think, evolved a bit in recent years. Stuff is more readily available; more understood. More practical.

And I think it's tapped into something cool out there in the fish world. And, at least in my mind- has exposed some things that really bring to the forefront the need to up our game just a bit.

For example, I see a lot of aquariums that hobbyists are putting out there on YouTube or wherever (which is awesome), purporting to represent a specific ecological niche or whatever, and yet offering seemingly authoritative information which- well- is wrong.

And most of it has to do with including features or materials which are simply incongruent with the habitat in question. Stuff that, while artistically awesome, is completely at odds with the reality of the habitat. 

Why is this a "problem?" Well, I wouldn't call it a "problem"- but I will suggest that it is something that needs to be addressed. I worry that we are a bit too caught up in the superficial aspects of the hobby. Too caught up in putting out a "picture", and not enough about educating in the process... I mean, it's great that we are sharing, but it carries with it a certain responsibility.

Because we shouldn't- despite our best intentions- espouse facts about a habitat on the most superficial level, and then put forth a work that is simply not accurate on the most fundamental level. 

Because there is enough inaccurate information out there. And we, as hobbyists, have a little responsibility to educate. Whether we like it or not. It's reality. Look, you don't have to be "Phd accurate", but the effort to explain interpretation and authenticity on every level should at least be addressed. "Interpretation" is one thing- yet presenting stuff with authority requires an extra step.

Of course, you could consider the fact that many of the exact materials specific to a certain habitat are simply not available to us as hobbyists, and that we need to utilize materials which represent those. So, if you want to judge every aquarium on the basis of being absolutely 100% faithful to the flora and fauna of a specific habitat or geographic region, a lot of these tanks will "fall short."

On the other hand, if you want to accept them as representations of certain habitats- most are spectacularly accurate and compelling in every way- inspiring, educating, and provoking discussion about the habitat they attempt to represent.

There is something extremely inspiring here. And romantic, in a way. 

Yeah, romantic: "..characterized by, or suggestive of an idealized view of reality."

Naturally, I have to implore everyone to enjoy the hobby the way YOU want to.

However, I also humbly request that, if you're creating an aquarium that you assert is to be a "realistic representation of a blackwater stream" habitat in The Amazon,  for example please do at least some "due diligence" research on the actual habitat, and make the effort to understand not only the superficial look- the "vibe"- but the function and the dynamics which affect the habitat.

I can hear the groans already:  "So, Fellman, you're saying that unless someone becomes an expert on a habitat and does things that are perfectly representative of  said habitat that it's a bad thing...?"


That's not what I'm getting at.

I'm merely suggesting that we try not to get too lost in the "romance" aspect of the habitat and the sexiness of the tank, without at least giving a bit of thought to the functional aspects which make the habitat so compelling and unique.

I mean, does the igapo habitat you're trying to recreate really have rocks in it? And why not? Doesn't that have something to do with the geology and conditions under which the habitat formed? 

Yeah, it does. And there are reasons for it which are quite interesting, compelling, and important to share with others, who maybe haven't even heard of this habitat. Being just a bit accurate with a detail like this really makes it that much better; perhaps it will inspire others to find out more...

I'm saying to just dive a little deeper.

Not to go crazy and "split hairs" on everything...However, to at least understand and perhaps execute in a manner that more accurately reflects the environmental niche that you are recreating in your aquarium. Because it matters to the hobby. To the environment...

An admittedly "romantic" notion, indeed.

Stay romantic. Stay diligent. Stay accurate. Stay creative. Stay honest...

And Stay Wet.


Scott Fellman

Tannin Aquatics 





April 15, 2019


Bark, like a dog. Tint like a geek.

People ask us what the fastest way to get a lot of tint into their aquarium is, and I have the most simple answer.


Yeah, bark.

Now, bark is interesting to me, because not only does it have an interesting aesthetic, in terms of it's "form factor"- it is a part of the tree which seems to have a lot of tannins and humic substances. In fact, the argument could be made that bark  has a greater concentration of these compounds than any other parts of the tree it comes from, because of the role of bark.

Tannins in the bark help precipitate out the enzymes and other protein exudates from bacteria and fungi thus not allowing these organisms to infect the tree. Tannin is typically concentrated in the inner bark (like, right below the surface), in what botanists call the "cambium layer." It is thought that older trees have bark which contains more tannins than younger trees, and by this measure, the lower parts of the tree contain a greater concentration of tannins than the top parts of the tree.

And of course, bark is known to contain agents which have been found in studies to control and eliminate chloroquine (CQ)-resistant and CQ-sensitive strains of bacteria. So, slightly more than anecdotal evidence exists that leaves and bark of many trees (Catappa comes to mind here) do have anti-fungal and anti-bacterial benefits for ornamental fishes when concentrated extracts of these substances are utilized in aquariums.

Of course, it's awful hard to determine the efficacy of the actual bark itself as a "tonic" of sorts, despite hobby-level claims. I prefer to think of them as a nice color-producing, humic substance-emmitting natural material which may have collateral benefits for our fishes! 

And of course, like many of the items we work with here at Tannin, we offer a few different varieties of bark. And interestingly, each brings its own unique aesthetic to the aquarium. Now, we'd be reaching if we suggested that each variety has some specific tannin or humic substance "profile"- although I suppose it's possible- just like coffee beans or wine grapes reflect the " terroir" (environment in which a particular wine or coffee is produced, including factors like the soil, topography, and climate) from which they come...But we have no real way of confirming that.

Suffice it to say, each type of bark we offer bring it's own "coolness" (technical term) to your aquarium!

We offer Catappa bark, the popular and sentimental fave, in several varieties from different locales. We offer Indian Catappa Bark, from Tamil Nadu region, which has a distinct rough surface area and comes in a rolled form factor. It has a very cool, almost "log-like" aesthetic.

Our other popular variety of Catappa bark is from Selatan, in Borneo. It is a "chunkier", thicker "cut", which tends to last almost indefinitely, releasing significant  color to the water, and recruiting biofilms on its hard surfaces. It's optimal for grazing fishes and shrimps.

The final "player" in our "trio" of Catappa bark is the variety from Sandakan in Borneo. It comes to us in a thinner, rolled "strip-like" form factor, making it perhaps the most "delicate" of the varieties that we offer; while still lasting almost indefinitely following submersion. It can be torn into smaller little pieces, supplementing more "ephemeral" materials like leaves on the substrate of your aquarium.

A lot of you wanted something that is truly "log-like" in both appearance and "scale", the recently-released Sri Lanka Mahogany bark is a fantastic botanical material for both creating a unique aesthetic in your hardscape, and for imparting a significant burst of tannins into the aquarium. Sourced from Kotugoda, Sri Lanka, this material is collected, rolled into sizable "logs", and dried. One thing about these bark pieces is that, although they have a unique shape that many fishes can exploit as a "shelter", we are not presenting them as a "Pleco Cave" or whatever. By happenstance, some pieces have wider openings, but it's purely random.

The latest, and perhaps most unique bark that we offer is Red Mangrove bark.  This bark comes to us from Hawaii, where it is legally collected and prepared for aquarium use. As it turns out, the Red mangrove is invasive in Hawaii, and the local government  and USDA are all too happy for us to take this material off of their hands!  We've used it for some time in aquairums, and I can tell you that it's  texturally interesting, aesthetically beautiful, and packed with tint-producing tannins! 

Yeah, it's neat to have choices...so we'll keep sourcing unique, sustainably-sourced bark for aquarium use. Wait- "sustainable?" Yeah, with the exception of the Mangrove bark, our suppliers collect their bark from their own, plantation-grown trees, which they rely on for other uses, like harvesting the leaves for aquarium use or tea.

Preparation of bark for aquarium use is pretty straightforward. You need to either soak it in freshwater for an extended period of time (several days) in order for it to saturate and perhaps release any surface contaminants (dirt, dust, etc.) that may be present, or boil the stuff in a pot for around 40 minutes or so, followed perhaps by an overnight soak in room temperature water. The idea of either approach is to "crack off" the surface pollutants (dust, dirt, etc.) and to help saturate and sink the bark.

Now, a lot of people tell us they're concerned about boiling or soaking their bark pieces before using in the aquarium. Doesn't this deplete much of the beneficial tannins and humic substances that you want so badly? The answer is, in short- no.  You needn't worry- Trust us, this stuff has enough of a "wallop"of the aforementioned substances that any preparation procedures won't "deplete" it of its valuable tannins! If kept dry, it can be stored indefinitely without losing its effectiveness. This is verifiable if you talk to anyone in the tanning trade who utilizes bark for creating stains!

As a food source, well, the idea of using bark is interesting! I've seen some fishes (the usual suspects like Plecos) rasping at it, as well as some shrimp.  More interestingly, I've seen fishes such as characins (Pencilfishes, in particular) picking at the bark quite often! Now, it's hard to tell if they are picking at the bark itself (perhaps unlikely, as gut content analysis of the wild fishes mentions nothing about bark!), or more likely, at algal, fungal or other growth on the faceted surfaces of the bark.

Nonetheless, bark can at least foster some of the natural food sources of a variety of fishes and shrimp, and is worth considering as a "functional" component of your blackwater aquarium.

There are a number of ways that you can utilize bark in your aquariums. You could use it as a "filter media" of sorts, placing it in a filter or sump, where water will flow over it, passively imparting tannins, humic substances, and that lovely golden-brown color that we seek so earnestly.

If you've been considering bark in one form or another in your aquarium, we hope that this little "tour" of the selection, aesthetics, and "functional applications" of this botanical material can bring amazing benefits to your aquarium and its residents! 

Tint like a geek!

Stay informed. Stay excited. Stay curious. Stay creative. Stay persistent....

And Stay Wet.


Scott Fellman

Tannin Aquatics 


April 14, 2019


A path through the forest...

To me, one of the most compelling aquatic scenes in Nature is the sight of a stream meandering into the forest.

There is something that calls to me- beckons me to explore, to take not of its intricate details- and to replicate some of its features in an aquarium- sometimes literally, or sometimes,. just taking components that I find compelling and utilizing them.

An important consideration when contemplating such a replication in our tanks is to consider just how these little forests streams form. Typically, they are either a small tributary of a larger stream, with the path carved out by rain or erosion over time. In other situations, they may simply be the result of an overflowing tributary during the rainy season, and as the waters recede later in the year, they evolve into smaller streams meandering through vegetation.

Those little streams fascinate me.

In Brazil, they are known as igarape, derived from the native Brazilian Tupi language. This descriptor incorporates the words "ygara" (canoe) and "ape"(way, passage, or road) which literally translates into "canoe way"- a small body of water which forms a route navigable by canoes.

A literal path through the forest!

These interesting little tributaries areare shaded by trees at the margins, and often cut for many kilometers through dense rain forest. The bottoms of these tributaries- formerly forest floor- are often covered with seed pods, twigs, leaves, and other botanical materials from the vegetation above and surrounding them. 

Although igapó forests are characterized by sandy acidic soils that have a low nutrient content, the tributaries that feed them are often found over a fine-grained, whitish sand, so as an aquarist, you a a lot of options for substrate!

In this world of decomposing leaves, submerged logs, twigs, and seed pods, there is a surprising diversity of life forms which call this milieu home. And each one of these organisms has manages to eke out an existence and thrive.

A lot of hobbyists not familiar with our aesthetic tastes will ask what the fascination is with throwing palm fronds and seed pods into our tanks, and I tell them that it's a direct inspiration from nature! Sure, the look is quite different than what has been proffered as "natural" in recent years- but I'd guarantee that, if you donned a snorkel and waded into one of these habitats, you'd understand exactly what we are trying to represent in our aquariums in seconds!

We also happen to like the way it looks, of course! 

These habitats not only provide physical environments for fishes, the vegetation surrounding them offers a diversity of foods, ranging from terrestrial insects to fruits.  Fishes commonly feed on the fruits and nuts knocked down from overhanging trees by various animals which reside in the forest canopy, such as birds and monkeys. 

Our inclusion of softer botanical materials in our biotope-inspired aquariums represents this accumulation which literally feeds the fishes residing in the igarape.

When materials from the trees fall to the forest floor, only to become submerged when the waters reach them, amazing physical and ecological features form. They form barriers, redirect flow, accumulate leaves, and impact what becomes the "underwater topography" of these unique habitats. 

I think so. I think that the representation of the igarape habitat in our aquariums is an exercise in both aesthetics and function.

Learning more about the dynamics of natural habitats and the ecology of the surrounding terrestrial environments is just one fascinating and compelling area of study that we as aquarists can really get into. Yes, it requires some study. It requires trying some new and seemingly wacky ideas (encouraging the accumulation of detritus, decomposing leaves, and epiphytic biofilm growth, for one thing!), and embracing some different aesthetics.

However, the potential for learning new things about our fishes, and perhaps being able to help them live longer, healthier lives, and to spawn them more reliably and productively, lessening our reliance on the collection of some wild specimens, could be significant. 

It's all out there for us to learn. Investigating a path through the forest might just lead to a new world of discovery for the hobby.

Stay adventurous. Stay curious. Stay creative. Stay observant. Stay undaunted...

And Stay Wet.


Scott Fellman

Tannin Aquatics.

April 13, 2019


Evolution. Patience. Time. The first mental shift.

Everything in our aquariums changes over time. How we accept that and embrace it is an important factor in how happy we are with our aquariums.

We talk so much about the idea of "evolution" of our natural-style aquariums that it starts to sound a bit repetitive, I think. 

However, the fact of the matter is that an aquarium which utilizes natural materials such as seed pods, leaves, and other botanicals for the bulk of it's "hardscape" will go through a period of time where it's sort of, well- "meh."

I hear this all the time.

It goes something like this:

The aquarium starts with a nice idea to utilize some cool seed pods and such, which, of course, you execute. And it usually looks fabulous for the first week or so.

And then, things change a bit...

The pristine seed pods and leaves start "softening" a bit. And what's that stringy stuff accumulating on the edges? Why, it's our old friend/nemesis/resource (depending upon your POV), biofilm.

Yup, the first mental shift that we have to make as lovers of truly natural style aquariums is an understanding that these tanks will not maintain the crisp, printing look without significant intervention on our part. And, by "intervention", I mean scrubbing, rinsing, and replacing the leaves and botanicals as needed. I mean, sure- you can do that. I know a bunch of people who do. They absolutely love super prisitne-looking tanks. 

I admit, I feel a bit sorry for these people who can't make the mental shift to accept the fact that Nature does here own thing, and will lay down a "patina" on our botanicals, gradually transforming them into something a bit different than when we started. When we don't accept this process, we sadly get to miss out on Nature guiding our tank towards its ultimate beauty- perhaps better than we even envisioned.

For some, it's really hard to accept this process. To let go of everything they've known before in the hobby. To wait while Nature goes through her growing pains, decomposing, transforming and yeah- evolving our aquascapes from carefully-planned art installations to living, breathing, functioning microcosms.

But, what about all of that decay? That "patina" of biofilm?

It's okay.

It's normal.

It's part of this type of approach. It's present in all natural aquatic systems. We just work with it instead of against it. In stead of trying to sanitize, edit, or otherwise "redirect" Nature, we understand that it will follow its own path, sometimes going through phases that we may not appreciate.


And guess what? It never stops.

And one more thing? The biofilms and that you might loathe so much tend to subside almost completely over time...If you are patient, and don't tear your tank apart in a frantic effort to eradicate one of Nature's finest creations.

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

Yeah, it requires a certain attitude.

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

A willingness to accept.

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

It simply takes time.

And patience.

Are you up to it? Can you make the first mental shift?

Spoiler: You've already started. Don't fight it.

Stay strong. Stay diligent. Stay calm. Stay patient. Stay observant. Stay resolute...

And Stay Wet.


Scott Fellman

Tannin Aquatics 




April 12, 2019


Random thoughts...

As you know by now, I am a fan of the random.

The unplanned. The seemingly haphazard. I find the idea of rain forest floors, flooded by rains, covered in branches, leaves, seed pods- now becoming part of the aquatic environment.

Ahh, branches.

And "twigs"


Let's think for just a second, about the "twigs"- the stems and branches that we love so much in our aquascaping. Those of us who obsessively study images of the wild tropical habitats we love so much can't help but note that many of the bodies of water which we model our aquariums after are replete with tree branches and stems. Since many of these habitats are ephemeral in nature, they are only filled up with water part of the year. The remainder of the time, they're essentially dry forest floors.

And what accumulates on dry forest floors?

Branches, stems, and other materials from trees and shrubs. When the waters return, these formerly terrestrial materials become an integral part of the (now) aquatic environment. This is a really, really important thing to think of when we aquascape or contemplate who we will use botanical materials like the aforementioned stems and branches. They impact both function and aesthetics of an aquarium...Yes, what we call "functional aesthetics" rears its head again!

There is no real rhyme or reason as to what stuff orients itself the way it does. I mean, branches fall off the trees, a process initiated by either rain or wind, and just land "wherever." Which means that we as hobbyists would be perfectly okay just sort of tossing materials in and walking away! Now, I know this is actually aquascaping heresy- Not one serious 'scaper would ever do that...right?

I'm not so sure why they wouldn't.  Look at Nature...

I mean, what's wrong with sort of randomly scattering stems, twigs, and branches in your aquascape? It's a near-perfect replication of what happens in nature. Now, I realize that a glass or acrylic box of water is NOT nature, and there are things like "scale" and "ratio" and all of that "gobbldeygook" that hardcore 'scaping snobs will hit you over the head with...

But nature doesn't give a f*^%# about some competition aquascaper's "rules"- and nature is pretty damn inspiring, right? There is a beauty in the brutal reality of randomness. I mean, sure, the position of stones in an "Iwagumi" is beautiful...but it's hardly what I'd describe as "natural."

Which begs the question: Who really cares? Do what you like! Okay, I"m coming around full circle here. The point is that we probably ascribe a bit too much into trying to achieve some completely artistic, perfectly proportioned placement of materials like twigs and branches, and could do a lot worse than literally dropping materials into our tanks (taking into account their size of course). 

Okay, I'm rambling on and on and probably digging a larger and deeper hole for myself with a lot of people...But hey- agitating is part of what we do here. We have to think beyond just the obvious, safe stuff now and then, right?

I think so.

Enjoy nature. Savor the utter randomness that can ensue when you just DO something. See how your fishes respond. Enjoy the mystery of "exploring" your own tank...and contemplate the natural processes which nature uses to "place" them.

Stay unrestrained by convention. Stay creative. Stay unique. Stay fascinated...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

April 10, 2019


The joy of...oatmeal.

Wednesday, 4:53AM PDT in Los Angeles...

I think I'm a bit weird.

When I was a kid, breakfast was one of those things I looked forward to every morning. I really liked- and still like- all of the foods associated with the morning meal. And one of those timeless menu items that I grew up with and still love is...oatmeal.


(Some of you in places other than the U.S. and Canada may call it "porridge" or some other name, but you know what I'm talking about here!)

It's probably one of the most maligned foodstuffs mankind has invented. Children have revolted against the stuff for centuries. Adults consumed it because there was no other choice...And the shit really hasn't changed all that much in the hundreds of years. It's been the humble food of millions for as long as anyone can remember. Practical, filling, simple.

Not sexy.

However, in 1997, the U.S. Food and Drug Administration determined that consuming oat bran or whole rolled oats can lower the risk of heart disease when combined with a low fat diet via the effect of oat beta gluten to reduce blood cholesterol levels. A similar conclusion in 2010 by the European Food Safety Authority cemented oatmeal (LOL) as an anointed superfood that is more than the humble morning meal of our forefathers.

What happened next? It became sort of...well, sexy. Maybe? Okay, "cool" maybe? 

(Ohh, nutritional porn! Don't show the kids!)

Yet, even after racking up international accolades, many people think about eating oatmeal the way we might approach a colonoscopy: It's something that is good for us, but not among life's more pleasant things. Others may not take such an extreme opinion of the stuff, comparing it to say, owning a minivan- safe and reliable, and comfortable for taking the kids to school and going to the supermarket, but not the vehicle of choice for a thrilling driving experience.

Dude, where the %&^^&*( are you going with this in a fish blog?

Think about this in the context of what we do. 

We advocate the idea of tossing leaves and dead pods into our aquariums...something that Nature has done in wild habitats for eons. Yet, something that has historically not been viewed kindly in the hobby. At least, not on a larger scale.

Sensing an analogy here?

Hobbyists have been adding natural materials into our tanks for generations, and faced a fair amount of criticism or garnered some odd looks along the way. Sure, adding this stuff creates a different sort of aesthetic which isn't for everyone-tinted water, an earthy vibe-more "random" and ephemeral.. And it seems to be a bit counter-intuitive to the hobby "narrative" that's been pushed on us for generations.

Yes, botanicals break down in the aquarium, imparting tannins and other compounds into the water. "Bioload" in the true sense. For years, we've been advised that water needs to be crystal clear and devoid of "excess" biological materials. Advice that, although sound to a great extent- has been somewhat overstated, IMHO. To the point where the concept of adding these materials was looked at with almost a "counterculture" mindset- as if it were some odd, potentially hazardous practice.

Or just not cool, at the very least.

Such criticisms lacked context, and failed to look at the upsides of this practice, when incorporated into an overall practice of good husbandry, patience, and observation.

And, in recent years, studies showning the benefits to fishes of humic substances and other compounds contained in leaves and botanical materials have made this practice not only more palatable- they've demonstrated that adding botanicals to an aquarium- and allowing them to "do their thing"- is a beneficial, practical approach to maintaining healthy tropical fishes and fostering their reproduction in our aquariums.

Functional practicality.

And the aesthetic:

Brown water, leaves, earthy tones; a really natural look- is catching the eyes of hobbyists and non-hobbyists alike. The mainstream aquascaping community is looking over their shoulders, wondering if there is more than the "Fairy Forests" and underwater dioramas they've been spitting out for the past decade...Perhaps, something more natural and equally interesting as a "Game of Thrones"-inspired rockscape (Whatever the hell that might be...I mean, it's not even 5 AM here...cut me some slack...)

There is something alluring.

Something interesting. Something not everyone likes still- yet something no longer looked at with outright dismissive attitudes. It's something worth familiarizing ourselves with- understanding the benefits of...and perhaps worth giving a go in our own tanks.

And we prepare the stuff for use by "cooking" it! Isn't that a sort of coincidence?

(Cue "Twilight Zone" theme here.)

The result is a truly natural aquarium in both form and function, courtesy of the humble botanical "detritus" from Nature herself.

Oatmeal. At least in the metaphorical sense.

Eat more oatmeal. Share the joy of oatmeal with others.

Create more natural-style aquariums using botanicals.

Spread the word.

Stay bold. Stay resilient. Stay creative. Stay proud. Stay a bit rebellious. Raise a little hell now and then...

And Stay Wet.


Scott Fellman

Tannin Aquatics 



April 09, 2019


More than just a pretty look.

I admit it freely: I'm a sucker for tinted water, decomposing leaves, seed pods, and an aquatic aesthetic which would likely have the most hardcore "Nature Aquarium" fan running for the carbon.

Of course, there are a lot of different things we can do with botanical materials besides just "tint" the water.  It's important to realize that materials like seed pods, leaves, bark, etc. are found in a variety of aquatic habitats all over the world, and their influence is more than just that pretty look. And, even with their presence in most every wild aquatic habitat of the world, they don't always result in brown water.

And, yes- it is absolutely possible (and entirely realistic) to have an aquarium filled with botanical materials that does not have the lovely "cafe au lait" look that we all know and love so well! In a twist on one of our own marketing slogans, "It's okay NOT to tint..."


Although the three "classical water types" (white, black and clear) are used by science to describe many of aquatic habitats, we aquarists tend to classify water as "blackwater" or "clearwater", which, although not scientifically "pure", and likely earns us the coveted "WTF" from scientists, tends to make our understanding and discussions easier!

It's certainly not a given that the presence of leaves, wood, and other botanical materials in a given body of water will result in brown water and low pH. Rivers like the Juruá, Japurá, Purus, and Madeira) are turbid, with water transparency that varies, and they transport large amounts of nutrient-rich sediments from The Andes. Their waters have near- neutral pH and relatively high concentrations of dissolved solids.

I have no illusions about  almost any aquarist deliberately wanting to recreate "turbid" water conditions in his/her tank- blackwater or otherwise-so I suppose we an eliminate that as a candidate for replication by all but the most "hardcore" of the hardcore hobbyists.

The Rio Xingu and Tapajós, on the other hand, are classic examples of "clearwater" rivers. One of the largest tributaries of the Amazon, the "Xingu" has an abundance of rock, and a higher content of dissolved minerals than a blackwater habitat like the Rio Negro. There is not much suspended matter because the rock formations which the river courses through are ancient and no longer erode in the current. The pH varies between 6 and 7.

And the fishes you'd keep in a Tapajos-themed (notice I didn't say "biotope", because that's a different level of detail, of course!) are legion. It's estimated to be home to at least 500 fish species! Favorites like   the aforementioned Dwarf Regani Pike Cichlid, Festivum, Geophagus, Checkerboard Cichlids (D. maculatus), Pristella Tetra, Pencilfishes, Leporinus, a bunch of Hemigrammus species, and even some Apistos are just a few of the many aquarium species at home in this type of habitat. This makes replicating this habitat a perfect challenge for the geeky aquarist!

As we've mentioned many times, water color, although helpful to us aquarists in some respects, is not a reliable indicator of the pH or ionic composition of the water! There is no substitute for good, old-fashioned water testing!

Interestingly (and perhaps, confusingly) the lower section of some Amazonian black-water rivers such as the Rio Negro, Tefé, Uatumã and Urubu in Brazil; Nanay in Peru and some streams in Colombia can have ionic composition and/or pH-values similar to the white water rivers, and not like the typical Amazonian blackwater rivers. It is thought by researchers that low electrical conductivity values can be responsible for this phenomenon. 

Now, sure, we could go on and on and on talking about all sorts of different wild aquatic habitats and how botanical materials influence both the water chemistry and the appearance of the water and habitat.  There are countless "variations on a theme" here that have implications for keeping a huge variety of tropical fishes. 

The implications of all of this stuff are that, if you're looking to accurately recreate the water conditions from which the specific fishes you keep come from, you would be well-served to determine, as accurately as possible, where they originated from. With wild-collected stock this might be easier (assuming the collectors/distributors possess and make this information known (Hear that guys? A good idea!) to hobbyists, the ultimate "end users" of their "product' (that sounds awful, calling fishes "product", but I think you get the point...)

This brief, highly-generalized discussion was not intended to be the last word on this topic. Merely a brief introduction of some "talking points" that we as hobbyists can use for  further research and discussion for this interesting and most important topic.

Now, there are numerous approaches to preparing water for our aquariums, and many, many different viewpoints and ideas among hobbyists as the "best" way to do things. However, at the end of the day, we all need to operate in a manner which we can understand, consistently replicate, and are comfortable with. And so much of this comes with education, discussion, and sharing of ideas. 

Study. Experience. Create. Contemplate. Report.

Stay bold. Stay open-minded. Stay excited. Stay intrigued. Stay creative...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


April 08, 2019


Nurturing Nature.

It's been very gratifying to see the incredible work being done  by aquarists in our community who have embraced the idea of a truly naturally-functioning and appearing aquarium. To see and hear discussions about things like "patience" and an understanding that various natural processes occur which we should study, understand, and embrace while our tanks establish themselves is nothing short of amazing.

It represents a shifting, evolving mindset that allows us as aquarists to meet Nature where she is and appreciate the 'journey" that we take with our aquariums at every stage.

As we've discussed many times, an aquarium has a sort of "cadence"- a speed and  sequence by which it establishes itself and runs in. A process that is dictated by biology, chemistry, and the "cards that were dealt" to the little closed ecosystems we create.

It all starts with a more-or-less sterile, empty tank, and then the addition of hardscape, such as substrate, rocks, and wood, followed by (in our case) botanical materials, ranging from leaves to seed pods to bark. The aquarium begins to establish itself; the botanical materials soften. The development of biofilms and that "patina" of algal growth begins. Perhaps you'll even encounter some cloudiness or turbidity from the microbial growth and influx of organics.

Ultimately, there is the unstoppable process of decomposition of these materials. All part of a process which cannot be rushed or "hacked" by us. Sure, we can change some of the things that happen in our tanks, like changing water, removing stuff from time to time...even switching out equipment such as lights or filters.

However, in the end (or the beginning, really!), Nature is in control.

She calls the shots.

This is scary for many hobbyists, I think. We've been indoctrinated by the hobby from our earliest days to attempt to take charge of as many processes and aspects of the aquarium as possible. To attempt to circumvent or avoid stuff like algae, detritus accumulation, decomposition, etc. You know- stuff that doesn't fit into the popular current narrative of what a "natural" aquarium is supposed to look like. Simply appropriating the word "natural" to describe the over-the-top, diorama-infested aquascaping scene that is rampant today overlooks eons of, well- reality.

Yeah, IMHO, we've been fed a load of crap.


I think we've attempted to "sanitize" or "edit" the aspects of Nature which don't meet some "standards" created in the past, when the natural habitats of our fishes and the processes by which they operated were dark, mysterious, and often misunderstood places. Environments in which danger and seemingly disastrous consequences awaited any hobbyist who dared allow Nature to take some control over what happened in our tanks.

And it continues, to a certain extent- to this day.

And, if you dig deep, you'll realize that this shallow view is not what guys like Amano were preaching, either. Rather, he was trying to figure out why natural habitats looked a certain way, and how they functioned. He emphasized the use of plants to recreate some of the beauty of Nature, but I don't think he ever intended for "fantasy forests" and winding underwater roads or miniature Stonehenges and Grand Canyons to be the "standard."

Rather, he proffered that we understand Nature:

"We have to remember that we either live in nature or not at all. Through building and maintaining beautiful natural aquaria, people relearn the intricate connections between forms of life: plants, fish, microorganisms and humans. Riches and beauty come from harmony, from balance. Aquaria are great teachers of this truth."

In other words, there's a lot more to this idea of a "natural aquarium" than just a cool look. 

With the unfortunate current narrative and emphasis being placed on the superficial and "artistic" aspects of our aquariums beyond almost anything else, it's more important than ever to "look over our shoulders" from time to time and condor that Nature is not some force to be feared, tamed, or otherwise sanitized. No. Rather, we need to make the attempt to understand what is happening in our tanks, why it happens, and how Nature really looks and acts.

We need to study, appreciate, and nurture these natural processes. Because when we make an effort to understand how they affect our aquariums, we gain an even greater appreciation for how they affect the natural habitats of our fishes, and how we need to protect and defend these processes and environments from damage caused by humankind.

We need to continue to see the parallels between the flooded tropical forest floors and the botanical-style natural aquarium system we set up in our living room. 

And we need to "re-program" fellow hobbyists to understand that this is not a bad thing. To see the beauty of a biofilm-encrusted branch, the delicate, ephemeral nature of a decomposing leaf, or the tinted, tannin-stained water, we can appreciate Nature as she really is. 

By polishing the "patina" off of our driftwood, siphoning out every drop of detritus, and removing as much of the "tint" from our tank's water as possible, we are effectively "editing" the beauty of Nature, rather than attempting to understand why things are the way they are, and how they are beneficial to our fishes.

Nurture the Nature in your aquarium. 

You might just change the hobby. 

Stay curious. Stay observant. Stay open-minded. Stay bold. Stay honest...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


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