November 09, 2020


Embracing the few. And the influential.

Okay, the title of this piece sounds like a political treatise, right?

Nah, it's all about my approach botanical-style aquariums. 

There is something I’ve come to embrace since I’ve been playing with botanical-style aquariums:

I like to limit elements.



Yeah, despite having access to an incredible array of botanicals, I have found over the years that it’s more appealing to my personal taste to utilize a less diverse selection of materials in a given aquarium. And it’s not just the aesthetic thing that motivates me to do this- it’s based upon some of the environments I’ve studied.

In many of the habitats we’ve studied, you will find multiple botanical elements, like leaves, seed pods, and twigs. However, the density and combination is profoundly influenced by a number of things.

  1. The terrestrial environment surrounding the aquatic habitat. In a dense jungle or rain forest, you’re likely to see a significant diversity of materials. In a flooded savannah or vernal pool, you might see less materials overall, as the density of materials is influenced primarily by what’s “on the ground” already when the water returns.
  1. The season. During certain times of the year in many locales, there is a greater density of materials falling into the water, because various trees are shedding leaves and seed pods. Or, you’ll see more botanicals in a given body of water because the water level is lower, and these materials are concentrated.


3)  Weather conditions. Wet, windy weather will typically result in more    materials being swept into the water, as well as a larger volume and higher velocity of water. You might see more stuff being “moved through” in areas of higher water volume, only accumulating in little pockets here and there.
4) Underwater “topography”. The depth, bottom contours, and overall physical structure of a lake, stream, river, or even a flooded forest or meadow profoundly influence the way materials accumulate, and how they accumulate. Stream features such as riffles and bends can serve to accumulate leaf litter banks, and to create natural “dams”, caused by fallen trees, rocks, etc.


There’s like a whole area of science devoted to this study of underwater “topography.”


To show you just how geeked-out I am about this stuff, I have literally spent hours pouring over pics and video screen shots of some of these igapo habitats over the years, and literally counted the number of leaves versus other botanical items in the shots, to get a sort of  leaf to botanical "ratio" that is common in these systems.

Geeked out.

Although different areas would obviously vary, based on the pics I've "analyzed" visually, it works out to about 70% leaves to 30% "other botanical items." 

The trees-or more specifically, their parts- literally bring new life to the waters. Some are present when the waters begin rising. Others continue to arrive after the area is flooded, falling off of forests trees or tumbling down from the "banks" of the stream by wind or rain.


Terrestrial trees also play a role in removing, utilizing, and returning nutrients to the aquatic habitat. They remove some nutrient from the submerged soils, and return some in the form of leaf drop. 

Interestingly, studies show that about 70% of the leaf drop from the surrounding trees in the igapo habitats occurs when the area is submerged, but the bulk of that is shedded at the end of the inundation period. 

The falling leaves gradually decompose and become part of the detritus in the food web, which is essential for many species of fishes. This "late-inundation leaf drop" also sets things up for the "next round" - providing a "starter" set of nutrients, doesn't it?

The materials that comprise the tree are known in ecology as "allochthonous material"-  something imported into an ecosystem from outside of it.  (extra points if you can pronounce the word on the first try...) And of course, in the case of trees, this also includes includes leaves, fruits and seed pods that fall or are washed into the water along with the branches and trunks that topple into the stream.  

You know, the stuff we obsess over around here! In fact, everything that we add to our aquariums is, in essence, allochthonous material.

These allochthonous materials support a diverse food chain that's almost entirely based on our old friend, detritus!

Yes, detritus. Sworn enemy of the traditional aquarium hobby...misunderstood bearer of life to the aquatic habitat.

Yeah, the detritus forms not only a part of the food chain in these systems- a very important part in the diet of many of our beloved's a literal physical structure that provides an area for fishes to forage, hide, and in some instances, spawn among.

A combination of elements- terrestrial and aquatic. All working together. 

Many other fishes which reside in these flooded forest areas feed mainly on insects; specifically, small ones, such as beetles, spiders, and ants from the forest canopy. These insects are likely dislodged from the overhanging trees by wind and rain, and the opportunistic fishes are always ready for a quick meal!


Interestingly, it's been postulated that the reason the Amazon has so many small fishes is that they evolved as a response to the opportunities to feed on insects served up by the flooded forests in which they reside! The little guys do a better job at eating small insects which fall into the water than the larger, clumsier guys who are more adapted to snapping up nuts and fruits with their big, gnarly mouths! 

And yes, some species of fishes specialize in detritus.

Yeah, detritus again. If we as aquarium hobbyists study the natural habitats of our fishes as diligently as some do the results of last year’s aquascaping contest, it’s easy see that not only is the word “natural” as we use it in the aquarium world really a perversion of the term, you’ll realize that natural aquatic habitats rarely look like what we think they do- and often rely on functions, processes, and materials which we tend to the nk of more as a nuisance than anything else.

Like detritus. And sediments. 

We need to get over our hobby-acculturated fear of these things. In well-managed, well-thought-out aquariums, these elements are as important and functional as they are in the natural habitats we model them after. They power an entire community of organisms which influence the stability, formation, and health of fish communities.

The seasonal shift from terrestrial to aquatic is a remarkable dynamic, with amazing processes that are well worth studying- and replicating- in our aquariums!

As we have discussed more times than you likely care to remember, decomposing leaves are the basis of the food chain, and the they produce forms an extremely important part of the food chain for many, many species of fishes. Some have even adapted morphologically to feed on detritus produced in these habitats, by developing bristle-like teeth to remove it from branches, tree trunks, plant stems, and leaf litter beds. 






Of course, it's not just the fishes which derive benefits from the terrestrial materials which find their way into the water. Bacteria, fungi, and algae also act upon the nutrients released into the water by the decomposing organic material from these plants. 

Plants (known collectively to science as macrophytes) grow in or near water and are either emergent, submerged, or floating, and play a role in "filtering" these flooded habitats in Nature. 

Many are simply terrestrial grasses which have adapted to survival under water for extended periods of time. This adds to the diversity of materials- both living and dead- in these compelling habitats.

A most interesting combination of elements, indeed.

A most compelling model.

A most fascinating example of a "functionally aesthetic" environment that you can duplicate in your home aquarium. Think about the environment, its external influences, the conditions, and the life forms that make use of it the next time you're conjuring up ideas for a new tank...It just might help you create one of the most amazing aquariums you've ever built!

In my experience, this utilization of a few elements, allowed to accumulate, decompose, and function as they do in Nature, do incredible things. For example, my several experiments with botanical-style, "self-feeding" aquariums.

Just a few botanical elements, slowly decomposing and recruiting fungal growths, biofilms, and detritus, have helped me create some very different-looking, yet smooth-functioning closed aquatic ecosystems.

The mixing of terrestrial and aquatic elements is also one which has and will continue to yield some very interesting, productive aquariums. I've reared a number of species of fry in these "fusion" systems, with remarkable success and limited supplemental feeding. 
The beauty of all this- besides the sheer fascination and yet-to-be-fully-appreciated benefits, is that we are still very much on the "ground floor" in experimenting with these unique approaches to botanical-style aquariums.

Like many of the ideas we discuss here, we all have the amazing opportunity to contribute to the growing body of knowledge about this stuff!

Don't be afraid. Be motivated and inspired! 

Stay part of this! Stay intrigued. Stay curious. Stay thoughtful. Stay diligent...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

November 06, 2020


Out of the woods...

Okay, so I admit, I'm no expert on the use of wood in aquariums. At least, I'm no expert on what's "hot", and what the sexiest way to arrange it is.

However, as you know- I'm pretty opinionated on stuff, and I'm happy to share my thoughts, despite the peril they occasionally place me in!

My philosophy on what wood type to utilize in your aquarium is, as you might expect from me- a combination of personal aesthetic tastes and functional attributes of a given specimen.

Yeah, I think it starts out with the most simple question: What type of wood appeals to you? Sure, you can address this angle by asking yourself what type of habitat or ecological niche you're trying to recreate in your tank, and what "configuration" would be most appropriate to do the job? That's kind of my starting place. 


Well, let's say you're trying to recreate the look of a tree stump or fallen tree section. You'd likely want to select a piece or pieces of wood that are thicker, "heavier-looking", and larger in size and stature to recreate such a feature. If you're trying to recreate the land/water interface of a flooded forest, and want to represent roots, then you'd likely select specimens of wood which are thinner, perhaps more twisted and gnarled in shape. 

Okay, time for a little detour into a rant!

Ironically, our hobby's most popular wood type- Manzanita, is- in my opinion, probably the least "realistic" wood you can use, in terms of how it looks/works when placed in an aquarium to represent a natural scene. (I have to say it...I really hate Manzanita. IMHO, the way most people employ it, Manzanita rarely looks like something you'd see underwater in Nature..I know, bring on the hate mail 🤬)


Maybe it's the way we place the stuff. I mean, we typically place the piece of wood on it's side, surround it with rocks and plants, and that's that. So, it's cool...but does it represent how a piece of wood would typically look/occur in a wide flooded forest, steam, or lake? 

Maybe that's it.

I'm sure plenty of people with talent do incredible stuff with Manzanita. Maybe I am just not a big fan of the stuff anymore.

Yeah, THAT'S it.

Micro hate rant over.

So, back to wood in general.

There's a fair amount of misconceptions and misinformation out there about what can work and what is not safe, etc. 

And a lot of misunderstanding about where and how wood in the aquarium fits into the whole "equation" of creating a functionally aesthetic aquarium habitat...

At the risk of adding to the confusion, I'll try to clear up some stuff here.

Believe it or not, if properly prepared, almost (I say…ALMOST- don't go overboard, here) any type of dried wood can be utilized in aquariums. The important thing is that the wood must be…well, DRY! It can’t be “live”, or have any "greenwood" or sap present, as these may have toxic affects on fishes when submerged. And it can't be of a variety know to be toxic to fishes or other animals. That's pretty obvious, right?

Sap can be toxic to fishes, even when dry, so if you see a piece of wood- even dry- that’s displaying some sap- it might be a good idea to remove the section where the sap is coming from, or to simply take a pass. And avoid wood with lots of sap, or that is known to contain stuff like that (Like, pine- which is a non-starter, right?)

In general, when it comes to wood, in our experience, it’s a better idea to purchase/collect your wood from sources known to offer “aquarium safe” wood, and not worry about suitability, toxic concerns, etc.


"Driftwood" is a nome de guerre I the hobby; a sort of a generic term for wood that has been dried over time, generally free of bark, (which, other than containing tannins and polyphenols, that are largely non-toxic in reasonable concentrations- is not that problematic, actually) and "greenwood" as outlined above. In most trees, the real chemically active substances are found in the leaves, live “greenwood”, and the sap.

So, a dry, largely bark-stripped piece of wood, free from sap, dried or otherwise, is generally pretty good to go, and is relatively stable and neutral.

Now, a lot of people ask me how we arrive at the selection of wood that we do, and why we don't offer certain types, yet offer others...

When it comes to the types of wood we offer, it's pretty straightforward. 

I select stuff that I think is cool.

You might fucking hate everything I offer.  I understand. And that's okay, because there are plenty of vendors out there who offer everything you could want, wood-wise. I just offer stuff I think would work with the kinds of aquariums we play with.

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

As someone who offers natural aquascaping materials for use in specialized aquariums, I long ago realized that I needed to stop chasing every hot type of wood that shows up on the market. I am generally clueless on "what's hot" in the aquascaping wood world, nor do I really care, to be perfectly honest.

"Scott, that's not very customer-centric. You claim to be so consumer focused, but it sounds like you couldn't care less what the market wants when it comes to wood!"

Yeah, confession. You're correct.

Because I'd go crazy trying to chase after all the "trendy" stuff all the time...And I'd be selling myself out offering stuff that I wouldn't want to use in my own tanks.

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

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

That answers that, I hope?

Of course, that also means I'm really the last guy who should be discussing what wood to use in your aquascapes. Why am I talking about this topic at all? Well, there are plenty of vendors who write "authoritative" articles on botanicals who are more clueless than I am about wood, so...

(ohh, had your coffee today, Fellman?)

Let's lighten this up a bit. 

Instead, lets have a brief discussion on what happens at that magical moment when we place wood in water...


It starts by considering the source of the wood.

Well, shit- it comes from (wait for it...) trees.

BOOM! Minds blown, I know!

For the sake of this discussion, let's just assume that you're working with wood that's been properly collected and is suitable for aquarium use.

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

And of course, there are the tannins.

Now, I don't know about you, but I'm always amused (it's not that hard, actually) by the frantic posts on aquarium forums from hobbyists that their water is turning brown after adding a piece of driftwood. I mean- what's the big deal?

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

The reality, as you probably have surmised, is that driftwood will continue to leach tannins pretty much for as long as it's submerged. As a "tinter", I see this as a great advantage in helping establish and maintain the blackwater look, and to impart the humic substances that are known to have health benefits for fishes.

Some wood types, like Mangrove, tend to release more tannins than others over long periods of time. Other types, like "Spider Wood", will release their tannins relatively quickly, in a big burst. Some, such as mangrove wood, seem to be really "dirty", and release a lot of materials over long periods of time.

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

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

Generally, no. I suppose, however,  some could take the view that this stuff is "fuel" for microorganism growth and run with it.

What other sort of stuff is in wood?

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

Why the botany lesson?

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

There is a lot of "stuff" in there!

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

We all know this, right?

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

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

Interestingly, the same "process" of "curing" happens naturally when tree trunks and branches fall into wild aquatic habitats.

It's not necessarily a "quick" process in Nature, either. So, we need not feel too bad about playing a "waiting game" when it comes to curing wood for aquariums

Could you boil wood and speed up the process?

Well, sure- if you have a cauldron or something large enough. SO, most of us just soak.

And we've talked about "in situ" curing of wood. You CAN do that. Absolutely, as we've discussed. I've done this a lot. However, it means a large amount of stuff being released into the water. It means levels of possible impurities that would demand significant water exchanges and aggressive use of chemical filtration...and there is NO way you'd want to add fishes for some time.

So, yeah- If you're patient, understand the need to maintain water quality, and can handle just looking at an empty tank with wood and botanicals in it...Have at it. 

Suffice it to say, that wood, when being submerged in an aquarium, will likely leach tannins into the water. It'll make the water dark...So, you "know the drill"- use activated carbon in quantity if you don't want this tint in your aquarium. 

And biofilms and fungi, which we've written about dozens of times in this very blog- will likely make their appearance at some point. We've talked ad nauseam how to deal with this stuff...

Yeah...that's like a whole different discussion we could have.

Bottom line here?

Choose the wood you like, which you feel best represents the habitat that you're trying to recreate. Understand that it will require preparation (soaking, etc.) before its really "set for use"- and that ideally, this should occur in a operate container instead of the aquarium it's ultimately destined for. Realize tannins and biofilms happen. While most wood types have their own "behavior" in the water, they all are comprised of the same substances, so there are generalities that make one type as good as any other. 

Be creative with how you use wood.

Combine it with other materials- or blend different wood types. Be original.

Kick some aquascaping ass.

Rant over.

Stay creative. Stay excited. Stay thoughtful. Stay bold...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

November 05, 2020


Surface film and other annoyances...

Someone asked what's the thing that I hate the most about botanical-style aquariums. I had to give it a lot of thought, but I think I found it.

I hate surface film.

What exactly is "surface film", and why is Scott so obsessed about the stuff?

Surface film is a sort of "aquarium vernacular" for "surface active compounds"- a scum of organics, microorganisms, proteins, and good old fashioned "dirt", among other things- which accumulates on the surface of the aquarium. Large organic molecules are not generally very soluble. They tend to adhere to all sorts of surfaces- the water/air interface being one such place that is immediately "in our faces" and is rather objectionable in appearance!

In some instances ,it's unavoidable- you know, like my ultra-small "urban Igapo" tanks, which typically run without any filters.


However, in larger, lightly-filtered tanks, this stuff becomes more of an issue to me.

The air/water interface is the "boundary" (technically called the "surface micro layer" by scientists) where all exchange occurs between the atmosphere and the aquatic environment. Interestingly, the The chemical, physical, and biological properties of the SML can differ significantly from the water just a few centimeters beneath the surface! 

In Nature, the concentration of these surface compounds depends on the source of the nutrients, as well as weather, like rain and wind. These organic compounds on the surface impact the the very physical and light admittance properties on the air/water interface. 

As aquarists, the biggest concern is that the surface film can interfere with gas exchange. Oh, and it looks like shit, right? 

Yeah, always seems to come back to aesthetics over almost everything, huh?

Well, maybe...

You see this stuff in almost every aquarium with a varying degree of annoyance, and it's just something that we "deal with", right?  Yeah, pretty much. And the reality is that it's likely not a huge deal for many hobbyists or their tanks. I mean, it's been something we've seen in tanks for over a century...and in the days before aquarium filters arrived, it was not an issue we heard mice about. And when we had goldfish in bowls as kids, it never seemed to bother us (so many other things about a goldfish in a bowl should have, right?)

Yet it's there. And to some of us, it's really ugly!

How do you deal with it?

Well, there are a few ways.

First, you can employ an aquarium which incorporates an overflow weir, which pulls water from the surface into the filter or filter chamber. That's what I am a huge fan of reef-ready aquariums, or many of the so-called "all-in-one" tanks, which draw water from the surface into the filter. This is a convenient way of pulling the most organic-rich water in the aquarium right into the filter.

The other alternative is to employ a surface skimming device.

Without me embarrassing myself while attempting to describe the way these things work, let's just say that they a device which employs an intake at the water surface, a small body, with an internal pump to draw in the water. These little gadgets do a remarkably good job at removing the aforementioned surface film. Now, I admit, they kind of look, well- shitty- but they are relatively easy to hide in most tanks, and get the job done!

If you're like me, and you hate looking at mechanical devices in your tanks, you either:  1) learn to live with it and appreciate the nice clean water surface, 2) hide the damn thing with clever hardscape, or 3) deal with the fucking surface film. 

Oh, before I wrap up this short, but epic treatise on one of my personal aquarium "pet peeves", I'd be remiss if I didn't mention my fave of the bunch..

The "Porsche" of surface skimmers, the Tunze Comline 3161. A beast of a device, it's a little thing, too (4.5” x 2.4” x 6.9”), and fits nicely into most small tanks, including the aggravating ADA 60F (which is only like 7" tall).

Like everything Tunze makes, it's seriously engineered, with innovative features and a powerful silent pump. Tunze makes reef-keeping gear, which means that it's designed for harsh environments and doesn't suck. So yeah, it's more expensive than the inexpensive knock of crap you find on Amazon or whatever, but it actually works. A good trade-off IMHO. This thing could easily serve as the sole filter/surface skimmer in a nano-sized tank, perhaps even one approaching 15 U.S. gallons (60L).

If you can hide it, it's worth every penny.

Again, the idea of surface film is just something that we have to deal with in the botanical-style aquarium.  And to many of you, it's no biggie. A non-issue, really. However, with a lot of decomposing leaves, botanicals, and other materials, it's probable that at some point, you're going to encounter stuff like this.  Sure, you can deal with the stuff with good surface agitation, too...But it always seems to accumulate in some far corner of the tank.

Yeah, surface agitation. Good!


So, you asked...I'm sharing. That's my aggravation...served up for your consideration!

Stay unfazed. Stay calm. Stay happy. Stay innovative. Stay resourceful...

And Stay Wet.


Scott Fellman
Tannin Aquatics 


November 04, 2020


Shrimp and "Anecdotal Nutrition?"

As botanical-style aquarists, we are keenly aware of the benefits of utilizing botanicals and leaves in our aquariums, so we're kind of used to the idea of them impacting our animals and aquarium habitats in a variety of ways. We are keenly aware that leaves and botanicals contain numerous compounds, ranging from humic substances and tannins, to stuff like lignin, cellulose, and even minerals.

We've seen what some of this stuff can do for our aquariums.

We've seen it with our own eyes; gauged the results for for ourselves. 

And there are still more questions than answers.

We have them. We receive a lot of them.


We receive a lot of questions from shrimp keepers, asking about the various merits of utilizing botanicals for environmental enrichment and nutrition for their animals. I love shrimp keepers, because they remind me a lot of reefers- absolutely obsessed with the well-being of their animals, with a heavy focus on finding materials or approaches which will benefit the shrimp.

And, like reefers, shrimpkeepers are bombarded by a lot of marketing, inflated claims of benefits, anecdotal assumptions, and out right falsehoods. And, like reefers, many have a built-in "bullshit meter" to look at some of these claims with a skeptical eye.

And they should. There is a LOT of stuff said about botanical materials and their use as food for shrimps- and some of it IS outright BS. Some of it is not, but it's pretty anecdotal, and if taken without question, might create the incorrect impression that these materials are more beneficial to shrimp than they really are.

The problem is that we know "a little" about the potential nutritional value of botanicals for shrimp- and that might spur a lot of speculation.

Huh? Well, let's look at what we DO know about this topic.  It's safe to say that most leaves and botanicals contain vitamins, amino acids, micronutrients, and other bioavailable compounds.


The real question I have is exactly how "available" they are to our shrimp from a nutritional standpoint. And how "nutrient dense" these leaves and botanicals are? Do our fishes and shrimp easily assimilate all they need in every bite, or do they have to eat tons of the stuff to derive any of these benefits?

Big questions, right?

I mean, we as hobbyists sort of assume that if these things are present in the botanicals, then our animals get a nice dose of 'em in every bite, right? And, it begs the question: Are they really directly consuming stuff like Casuarina cones, or feeding on something else on their surfaces (more on this later)?

I think it's "yes" on both.

And the nutrition that they derive from consuming them?

Well, that's the part where I say, I don't know.

I mean, it seems to make a lot of sense to me...However, is there some definitive scientific information out there to prove this hypothesis?

A lot of the "botanicals for food thing" in the hobby (no, really- it's a "thing!") comes from the world of shrimp keepers. This isn't new stuff to them. They've been touting this stuff in the hobby for a long time. A lot of it is based upon the presence of materials like leaves and such in the wild habitats where shrimp are found. I did some research online (that internet thing- I think it just might catch on...) and learned that in aquaculture of food shrimp, a tremendous variety of vegetables, fruits, etc. are utilized, and many offer good nutritional profiles for shrimp, in terms of protein, amino acids, etc.

They're all pretty good. Our friend Rachel O'Leary did a great job touching on the benefits of botanicals for shrimp in her video last Fall.

So, which one is the best? Is there one? Does it matter? In fact, other than sorting through mind-numbing numbers ( .08664, etc) on various amino acid concentrations in say, Mulberry leaves, versus say, Sugar Beets, or White Nettle, or whatever, there are not huge differences making any one food vastly superior to all others, at least from my very cursory, non-scientific hobby examination! 

Now, leaves like Guava, Mulberry, etc. ARE ravenously consumed by shrimp and some fishes. It's known by scientific analysis that they do contain compounds like Vitamins B1, B2, B6, and Vitamin C, as well as carbohydrates, fiber, amino acids, and elements such as Magnesium, Potassium, Zinc, Iron, and Calcium...all important for many organisms, including shrimp. Guava leaves are particularly good, according to some of the studies I read because, apparently, the bulk of the nutrients they contain are more "readily available" to animals than other leaves.

Well, that's pretty important, isn't it?

I think so!

Now, it may be coincidental that these much-loved (by the shrimp, anyways) leaves happen to have such a good amount of nutritional availability, but it certainly doesn't hurt, right?

Other leaves, such as Jackfruit, contain "phytonutrients", such as lignans, isoflavones, and saponins that have health benefits that are wide ranging for humans. There is some conflicting data regarding Jackfruit's alleged antifungal capability  However, the leaves are thought to exhibit a broad spectrum of antibacterial activity in humans. In traditional medicine, these leaves are used to help heal wounds as well.

Do these properties transfer over to our fishes and shrimp?

We are not aware of any scientific studies that have been completed to correlate one way or another. That being said, they seem to flock to these leaves and graze on them directly- and on the biofilms which accumulate on their surface tissues.

Oh, the biofilms again!

As I mentioned before, the "shrimp side" of the hobby reminds me in some ways of the coral part of the reef keeping hobby where I spent considerable time (both personally and professionally) working and interacting with the community. There are some incredibly talented shrimp people out there; many doing amazing work and sharing their expertise and experience with the hobby, to everyone's benefit!

Now, there are also a lot of people out there in that world -vendors, specifically- who make some (and this is just my opinion...), well - "stretches"- about products and such, and what they can do and why they are supposedly great for shrimp. I see a lot of this in the "food" sector of that hobby specialty, where manufacturers of various foods extoll the virtues of different products and natural materials because they have certain nutritional attributes, such as vitamins and amino acids and such, valuable to human nutrition, which are also known to be beneficial to shrimp in some manner. 

And that's fine, but where it gets a bit anecdotal, or - let's call it like I see it- "sketchy"- is when read the descriptions about stuff like leaves and such on vendors' websites which cater to these animals making very broad and expansive claims about their benefits, based simply on the fact that shrimp seem to eat them, and that they contain substances and compounds known to be beneficial from a "generic" nutritional standpoint- you know, like in humans.

All well-meaning, not intended to do harm to consumers, I'm sure...but perhaps occasionally, it's just a bit of a stretch.

I just wonder if we stretch and assert too much sometimes?

Now, I'm not saying that it's "bad" to make inferences (we do it all the time with various topics- but we qualify them with stuff like,  "it could be possible that.." or "I wonder if..."), but I can't stand when absolute assertions are made without any qualification that, just because this leaf has some compound which is part of a family of compounds that are thought to be useful to shrimp, or that shrimp devour them...that it's a "perfect" food for them, with enormous benefits. 

It's just a food- one of many possibilities out there. That's how I think we need to look at things.

Of course, I hope I'm not out there adding to the confusion! We try to hold ourselves to higher standards on this topic; yet, like so many things we talk about in the world of botanicals, there are no absolutes here.

What is fact is that some botanical/plant-derived materials, such as various seeds, root vegetables, etc., do have different levels of elements such as calcium and phosphorous, and widely varying crude protein. Stuff that's known to be beneficial to shrimp, of course. These things are known by science, largely through studies down on shrimp farmed for human consumption.

Yet, I have no idea what some of the seed pods we offer as botanicals contain in terms of proteins or amino acids, and make no assertions about this aspect of them, above and beyond what I can find in scientific literature.

No one else does, either.

However, I suppose that one can make some huge over-generalizations that one seedpod/fruit capsule is somewhat similar to others, in terms of their "profile" of basic amino acids, vitamins, trace elements, etc. (gulp). We can certainly assume that some of this stuff, known to have nutritional value, can make these materials potentially useful as a supplemental food source for fishes and shrimps.

Yet, IMHO that's really the best that we can do until more specific, scientifically rigid studies are conducted. And we can feed a wide variety of stuff to our shrimp- sort of the equivalent of throwing a bunch of spaghetti on the wall to see what sticks!

Now, we may not know which seed pods and such in and of themselves are more nutritious to fishes and shrimp than others, but we DO know from simple observation that some are better at "recruiting" materials on their surfaces which serve as food sources for aquatic organisms!

Yeah, I'm talking about the biofilms and fungal growth, which make their appearance on our botanicals, leaves, and wood after a few weeks of submersion...

We know that shrimp seem to love grazing on biofilms, and that the nutritional benefits of biofilms are pretty well established. They are a rich source of sugars and other nutrients, and could even prove to be an interesting addition to a "nursery tank" for raising fry and larval shrimp. Like, add a bunch of leaves and botanicals, let them do their thing, and allow your fry to graze on them!


And of course, it's long been known from field studies that as leaves and other plant materials break down, they serve as "fuel" for the growth of biofilm, fungi and microorganisms...which, in turn, provide supplemental food for fishes and shrimps. I've seen a bunch of videos of shrimps and fishes in the wild "grazing" over fields of decomposing leaves and the biofilms they foster.

Ahh, biofilms again.

Refresher for you:

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.

Biofilms on decomposing leaves are pretty much the foundation for the food webs in rivers and streams throughout the world. They are of fundamental importance to aquatic life.

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.

Hmm, sounds sort of like Instagram, huh?

(The above graphic from a scholarly article illustrates just how these guys roll.)

And we know from years of personal experience and observation in the aquarium that fishes and shrimp will consume them directly, removing them from virtually any surface they form on.

And some materials are likely better than others at recruiting and accumulating biofilm growth. The "biofilm-friendly" botanical items seem to fall into several distinct categories: Botanicals with hard, relatively impermeable surfaces,  softer, more ephemeral botanical materials which break down easily, and hard-skinned botanicals with soft interiors, and...

Okay, wait- that kind of covers like, everything, lol.


There are a few that really stand out, like the Dysoxylum pod.

Dysoxylum binectariferum, which is found in the forests of tropical India, but ranges as far afield as Vietnam. It's found in in alluvial soil conditions (clay and sand) and along rivers and streams...right up our proverbial "alley", huh?

In India, it is also known by many other names such as, "Indian White Cedar", "Bili devdari", "Bombay White Cedar", "Velley Agil", "Porapa", "Vella agil", and "Devagarige."

The tree is an important component of tropical rain forests, typically from India, but found in other regions.


The tree grows to height of 120feet/40 m height, has bark which is greyish-yellow in color, with inner bark a creamy yellow color. The fruits that ripen during June–July are capsules. In India, apart from its economic importance for building and furniture making, it is an important ingredient in traditional medicine. The fruit has a chemical composition known by the name “ashtagandha”, which means "fragrant smell", and is used for making incense sticks that are commonly used for worship.

Interestingly, compounds derived from the tree itself are also known by modern medical researchers to have extremely valuable medicinal properties...

Notice, we said, "the tree itself?"

Dysoxylum binectariferum bark was identified as an alternative source of CPT, through  a process of bioassay-guided isolation. Camptothecin ( known to clinical researchers as "CPT 1") is a potent anticancer product, which led to the discovery of two other clinically used anticancer drugs, Topotecan and Irinotecan. 

Rohitukine is another compound that accumulates in a significant amount in seeds, trunk bark, leaves, twigs, and fruits of D. binectariferum. Rohitukine is an important precursor for the synthesis of other potential anticancer drugs


And all I wanted was some seed pods to feed shrimp! With all of those medicinal uses, has anyone ever used them before in aquariums before we started playing with them for this purpose?

I'm doubtful, but you never know...

And why did I just go on a tangent about this tree and it's seed pod? 

Because it's an example of the kind of information that you can extrapolate from areas of study outside of aquariums. And half of the benefits ascribed to Dysosxylum are based on its bark and leaves, neither of which we work with. 

You can make all sorts of inferences and assumptions about their benefits, and how they might apply to shrimp, solely based on this kind of stuff.

Don't do that. 

Don't assume that, because the tree and its other parts have compounds which are known to provide certain benefits, that it's 100% certain that the seed pods do, too. 

Yeah, we utilize the seed pod. Not the bark, the branches, or the leaves. We know that our shrimp eagerly graze on its soft interior, and the biofilms which are recruited on the pod as it breaks down.

Research, experiment, and draw your own conclusions, based on the performance you experience with your shrimp. Don't rely on anecdotal assumptions. Don't assume that because the tree can do all of these things, that the leaves or seed pods can do them, too...and that they can impart such benefits to shrimps!

"Anecdotal nutrition" is something we shouldn't accept without some skepticism.

It's a lot to take in- and I see how this might be a bit disappointing to some. The reality is that this is exciting- it's invigorating, because sorting through the sea of anecdotal assumptions and hypothesis, in an effort to benefit our animals, is incredibly exciting! 

Stay informed. Stay bold. Stay curious. Stay excited. Stay resourceful...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


November 03, 2020


The start of the journey...And the direction it takes us...

It seems incredible to me that the world of blackwater, botanical-style aquariums is still “finding its tribe”, with lots of hobbyists trying this approach for the first time. And as the techniques evolve, the processes become more refined..or even more unusual.... I was thinking about this today when I was playing with a new tank I'm starting up in my office.

I utilized some mangrove wood which was not really "cured"- something I've done before with this wood, and the inevitable cloudiness and tint came quickly. And it got me thinking...

When you add botanicals to an aquarium, particularly a brand new one, there is almost always some sort of cloudiness initially. This is caused by several factors, ranging from good old “dirt” coming off of their surfaces, to dissolving lignin, cellulose, and of course, tannins. It’s a complex organic “brew”, which is released into the water as the materials begin to break down.


Of course, all of this material dissolving into the aquarium can create cloudiness.That's probably your first sign that "things" are happening! We often see such cloudiness in aquariums when we may not have fully prepared our botanicals, or wood. 

Will it go away on its own, without our intervention?

In my experience, it will...eventually. And of course, "eventually" can be days, weeks...or longer. No guarantees. And "without our intervention" is a sort of vague thing. You can let Nature sort it out, as she's done for eons. I mean, you could...could- even "cure" wood and botanicals "in situ." I've done it before. I wouldn't recommend it, however.

"Well, shit, Scott- you said you 'could'- so how would you?"

Damn, I did. And I can run the risk of being pretty irresponsible here, I know. Let me elaborate further. 

Well, there are a few approaches you can take to managing this stuff.

You can employ some chemical filtration media, such as activated carbon, to help clear up the cloudiness and perhaps remove some of the organics. You could perform water exchanges, with the knowledge that this may disrupt or slow the development of a significant population of beneficial bacteria. 

You can do this. You won't be adding fishes for a while, but you can do this. You can add bacteria, however. In fact, this is where our bacterial inoculant, "Culture", can excel. It is comprised of the hardy, incredibly versatile Purple Non-Sulphur Bacteria (PNSB), Rhodopseudomonas palustris.

Like nitrifying bacteria, PNSB metabolize ammonium and nitrite and nitrate. And they're not just important to the nitrogen cycle. They're also capable of aerobic organoheterotrophy - a process of removing dissolved organics from the water column- just like other microbes!

PNSB are useful for their ability to carry out a particularly unusual mode of metabolism: anaerobic photoheterotrophy. In this process, they consume organic wastes while inhabiting moderately illuminated and poorly oxygenated microhabitats (patches of detritus, leaf litter beds, shallow depths of substrate, deeper pores of expanded clay media, etc.).

By competing with other anaerobes such as methanogenic archaeans  (more about them later) and sulfate-reducing bacteria for food, these voracious "sludge-eaters" significantly reduce the production of toxic byproducts such as methane and hydrogen sulfide!

It’s important to understand that your best allies in the cause of establishing a new aquarium are bacteria and fungi, as we’ve talked about repeatedly.

Bacteria will arrive in your aquarium through a number of means- on leaves and seed pods, in substrate (particularly if you’re using material from an established one), wood, etc. The nitrifying bacteria that we admire so much are present in almost every aquatic system- even a brand new aquarium. However, there simply aren’t enough of them in a new aquarium to process the waste produced by a significant fish population.  And of course, to grow the population of these beneficial bacteria, you need to supply then with their major energy source- ammonia.


Without re-hashing the whole well-trodden nitrogen cycle stuff, we know by now that these bacteria will oxidize the ammonia and convert it to nitrite, which a second group of bacteria process and convert to less harmful compounds, specifically, nitrate. When both of these types of bacteria reach a population sufficient to process the available energy sources, you’ve got an aquarium that’s “cycled.”

"Aquarium Keeping 101", right?

Yeah, it should be.

Of course, with the pH in blackwater aquariums generally falling into the range of 6.0-6.8, you’ll see a slower processing of ammonia and nitrite. And when you get really low pH, as we’ve talked about before (like 5.5pH or lower), these organisms essentially shut down, and a new class of organism, Archaens, take over. Now, that;’s a whole different thing for a different blog, but suffice it to say, the lower pH, botanical-style/blackwater aquarium is a different animal altogether! 


I think that the real key ingredient to managing a low pH system (like any system) is our old friend, patience! It takes longer to hit an equilibrium and/or safe, reliable operating zone. Populations of the organisms we depend upon to cycle waste will take more time to multiply and reach levels sufficient to handle the bioload in a low-pH, closed system containing lots of fishes and botanicals and such.

This certainly gives the bacterial populations more time to adjust to the increase in bioload, and for the dissolved oxygen levels to stabilize in response to the addition of the materials added-especially in an existing aquarium. Going slowly when adding are botanicals to ANY aquarium is always the right move, IMHO.

And at those extremely low pH levels?


They sound kind of exotic and even creepy, huh?

Well, they could be our friends. We might not even be aware of their presence in our systems...If they are there at all.

Are they making an appearance in our low pH tanks? I'm not 100% certain...but I think they might be. Okay, I hope that they might be. 


Archaeans include inhabitants of some of the most extreme environments on the planet. Some live near  vents in the deep ocean at temperatures well over 100 degrees Centigrade! true "extremophiles!" Others reside in hot springs, or in extremely alkaline or acid waters. They have even been found thriving inside the digestive tracts of cows, termites, and marine life where they produce methane (no comment here)  They live in the anoxic muds of marshes (ohhh!!), and even thrive in petroleum deposits deep underground.


(Image used under CC 4.0)


Yeah, these are pretty crazy-adaptable organisms. The old cliche of, "If these were six feet tall, they'd be ruling the world..." sort of comes to mind, huh?

Yeah, they’re fucking beasts….literally.

Could it be that some of the challenges in cycling what we define as lower ph aquariums are a by-product of that sort of "no man's land" where the pH is too low to support a large enough population of functioning Nitrosomanas and Nitrobacter, but not low enough for significant populations of Archaea to make their appearance?


I'm totally speculating here. I could be so off-base that it's not even funny, and some first year biology major (who happens to be a fish geek) could be reading this and just laughing…

I still can't help but wonder- is this a possible explanation for some of the difficulties hobbyists have encountered in the lower pH arena over the years? Part of the reason why the mystique of low pH systems being difficult to manage has been so strong?

Could it be that we just need to go a LOT slower when stocking low pH systems?

Yeah, we should go slower.

And yes, you can "cure" everything in situ, fi you understand what's happening, what the potential downsides are, and how to manage this process. You need to just be patient. 

Right after the initial "break in" and "cycling" process comes the next phase- 


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.

And of course, the ultimate "state" to which leaves and other botanical materials "evolve" to is our old friend...detritus.

And of course, that very word- as we've mentioned many times here- has frightened and motivated many hobbyists over the years into removing as much of the stuff as possible from their aquariums whenever and wherever it appears.

Siphoning detritus is a sort of "thing" that we are asked about near constantly. This makes perfect sense, of course, because our aquariums- by virtue of the materials they utilize- produce substantial amounts of this stuff.

Now, the idea of "detritus" takes on different meanings in our botanical-style aquariums...Our "aquarium definition" of "detritus" is typically agreed to be dead particulate matter, including fecal material, dead organisms, mucous, etc.

And bacteria and other microorganisms will colonize this stuff and decompose/remineralize it, essentially "completing" the cycle.

Decomposition is so fundamental to our "game" that it deserves mentioning again and again here!

Now, a lot of people may disagree, but I personally feel that THIS phase, when stuff starts to break down, is the most exciting and rewarding part of the whole process! 

And perhaps- one of the most natural...

How we start our systems- the approach that we take, the way we react and adjust- are fundamental parts of the equation. And yeah, there ARE a lot of different ways you can go. Some will raise a few eyebrows. Some will make fellow hobbyists think that you're crazy. But you CAN take different routes.

And you should at least think about them now and then.

Stay creative. Stay studious. Stay engaged. Stay excited...

And Stay Wet.


Scott Fellman

Tannin Aquatics 





November 02, 2020


Water with "flavor", and the distinctions between color and clarity...

One of the interesting "side effects" of being called "Tannin Aquatics" is that you give everyone the impression that all you specialize in is creating aquariums with lots of leaves and stuff and golden-brown, tinted water.

Makes sense, for sure. And yeah, we like to think of ourselves as big fans and supporter of the blackwater, botanical-style aquarium. However, I think it's okay to  mention that it's also okay NOT to tint. It's okay to embrace all sorts of different looks.

Huh? Why are you even discussing this?

Well, it's because so many people ask me questions about this stuff, and what defines a botanical-style aquarium, and what makes "blackwater", and...

Somewhere along the line, some hobbyists seem to feel that the the idea of a botanical-style aquarium is only one that has golden-brown water. It must have a certain look.

Ridiculous, I say. Where this kind of crap comes from, I'm not sure. 

Yeah, I'm saying it here: You can use botanicals and other natural materials in aquariums that are essentially clear water. It's not uncommon to find leaves, twigs, and other botanical materials in wild habitats which have essentially clear water.

And of course, you can do the same in the aquarium.

Let's just reinforce this by sharing a bit of information about some of my favorite habitats in South America, the Orinoco flood plains. As always, it seems to go back to geology.

In the Orinoco, you have blackwater and "white water" areas. The"white water" habitats, although not deeply tinted, nor crystal clear, are often a bit turbid. The seasonal turbidity of these “white waters” can be significant, and can actually help support some benthic algal growth.

These "white waters" contain large amounts of dissolved and suspended solids, which are produced by weathering of the soils and rocks high in the Andes. This  rapid "weathering" produces the seasonal turbidity we're talking about here. Examples of "white water" rivers would be the main course of the Amazon, as well as the Japura and Jurua rivers.

By contrast, black waters flow primarily through the Guayana Shield, which has been weathered so extensively over the eons that it contributes only small amounts of suspended and dissolved solids into the water. We've talked about this many times before.

More confusing (or interesting, actually): Because it receives both whitewater and blackwater tributaries, the Orinoco is a mixture of water types with of strongly contrasting physical, chemical, and biological characteristics. A most interesting mix!

And then, there are rivers like the Tapajos or the Xingu, which have an almost greenish tint to them, although ecologists classify it as a "clearwater" river.  They flow from the geologic structure known as the "Central Brazilian Archaic shield", and have low amounts of sediments and dissolved solids. These waters feature a lot of wood and fine, sandy substrates. 


So, the point of all of this geological meandering to illustrate that the world of water is every bit as complex as any other aspect of the natural world.

And if it has you a bit confused, don't be. The point that I'm trying to make here is that the color of the waters which we obsess over are an amalgamation of a variety of factors, many of which we can replicate, to some extent, in the aquarium.

When we add materials such as leaves, wood, and seed pods to water, they impart tannins, humid substances, and other materials into the water.  This is similar to what happens in Nature, however, it's only part of the process, as we've discussed before.

And of course, you have the whole issue of turbidity and clarity.

we as fish geeks seem to associate color in water with overall "cleanliness", or clarity. The reality is, in many cases, that the color and clarity of the water can be indicative of some sort of issue, but color seems to draw an immediate "There is something wrong!" from the uninitiated!

And it's kind of funny- if you talk to ecologists familiar with blackwater habitats, they are often considered some of the most "impoverished" waters around, at least from a mineral and nutrient standpoint.

In the aquarium, the general hobby at large doesn't think about "impoverished." We just see colored water and think..."dirty." 

And of course, this is where we need to separate two factors:

Cloudiness and "color" are generally separate issues for most hobbyists, but they both seem to cause concern. Cloudiness, in particular, may be a "tip off" to some other issues in the aquarium. And, as we all know, cloudiness can usually be caused by a few factors:

1) Improperly cleaned substrate or decorative materials, such as driftwood, etc. (creating a "haze" of micro-sized dust particles, which float in the water column).

2) Bacterial blooms (typically caused by a heavy bioload in a system not capable of handling it. Ie; a new tank with a filter that is not fully established and a full compliment of livestock).

3) Algae blooms which can both cloud AND color the water (usually caused by excessive nutrients and too much light for a given system).

4) Poor husbandry, which results in heavy decomposition, and more bacterial blooms and biological waste affecting water clarity. This is, of course, a rather urgent matter to be attended to, as there are possible serious consequences to the life in your system.

And, curiously enough, the "remedy" for cloudy water in virtually every situation is similar: Water changes, use of chemical filtration media (activated carbon, etc.), reduced light (in the case of algal blooms), improved husbandry techniques (i.e.; better feeding practices and more frequent maintenance), and, perhaps most important- the passage of time.

There are of course, other factors that affect clarity, like fishes that dig or otherwise disturb the substrate and wood with their grazing activities, but these are not necessarily indicative of husbandry issues.

Okay, that was "Aquarium Keeping 101", actually.

Although we all seem to know this, I hear enough comments and questions about the color of the water and its relation to "cleanliness" in  natural, botanical-style blackwater systems that it warranted this seemingly "remedial" review!

Remember, just because the water in a botanical-influenced aquarium system is brownish, it doesn't mean that it's of low quality, or "dirty", as we're inclined to say. It simply means that tannins, humic acids, and other substances are leaching into the water, creating a characteristic color that some of us geeks find rather attractive. If you're still concerned, monitor the water quality...perform a nitrate test; look at the health of your animals. What's happening in there?

People ask me a lot if botanicals create "cloudy water" in their aquariums, and I have to give the responsible answer- yes. Of course they can!

If you place a large quantity of just about anything that can decompose in water, the potential for cloudy water caused by a bloom of bacteria exists. The reality is, if you don't add 3 pounds of botanicals to your 20 gallon tank, you're not likely to see such a bloom. It's about logic, common sense, and going slowly.

Remember, too, that some "turbidity" in the water, in either a "whitewater" or "blackwater" system, is natural,expected, and not indicative of a problem. In many natural settings, water is chemically perfect but not entirely "crystal clear."  I believe that a lot of what we perceive to be "normal" in aquarium keeping is based upon artificial "standards" that we've imposed on ourselves over a century of modern aquarium keeping. Everyone expects water to be as clear and colorless as air, so any deviation from this "norm" is cause for concern among many hobbyists.

In my home aquariums, and in many of the really great natural-looking blackwater aquariums I see the water is dark, almost turbid or "soupy" as one of my fellow blackwater/botanical-style aquarium geeks refers to it. You might see the faintest hint of "stuff" in the water...perhaps a bit of fines from leaves breaking down, some dislodged biofilms, pieces of leaves, etc. Just like in nature. Chemically, it has undetectable nitrate and phosphate..."clean" by aquarium standards.

Sure, by municipal drinking water standards, color and clarity are important, and can indicate a number of potential issues...But we're not talking about drinking water here, are we?

"Turbidity." Sounds like something we want to avoid, right? Sounds dangerous...

On the other hand, "turbidity", as it's typically defined, leaves open the possibility that it's not a negative thing:

 "...the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air..."  

What am I getting at?


Well, think about a body of water like an igapo adjacent to the Rio Negro, as pictured above in the photo by Mike Tuccinardi. This water is of course, "tinted" because of the dissolved tannins and humic substances that are present due to decaying botanical materials.  And it's also a bit "turbid" because of the fine particulate matter from these materials, too.

I would argue that these conditions are not "unhealthy" to fishes, right?

Okay, we've beaten the living shit out of that, haven't we?


The substrates that we utilize influence both the aquarium's appearance and its chemistry. This is, of course, essentially what happens in Nature. In the flooded forests of South America and elsewhere terrestrial materials, such as botanicals, roots, branches, leaves, and soil play a role in shaping the aquatic ecosystem which arises following the seasonal inundation.

The mix of materials which comprise these unique habitats has definitely been an inspiration for me to create quite a few different aquariums over the years! There is so much we can learn from studying these systems that we can apply in our hobby work!

That's different from "cloudy" or "turbid", however. 

It's a distinction that neophytes to our world should make note of. The "rap" on blackwater aquariums for some time was that they look "dirty"- and this was largely based on our bias towards what we are familiar with. And, of course, in the wild, there might be some turbidity because of the runoff of soils from the surrounding forests, incompletely decomposed leaves, current, rain, etc. etc.

None of the possible causes of turbidity mentioned above in these natural watercourses represent a threat to the "quality", per se. Rather, they are the visual sign of an influx of dissolved materials that contribute to the "richness" of the environment. It's what's "normal" for this habitat. It's the arena in which we play in our blackwater, botanical-style aquariums, as well.

Obviously, in the closed environment that is an aquarium, "stuff" dissolving into the water may have significant impact on the overall quality. Even though it may be "normal" in a blackwater environment to have all of those dissolved leaves and botanicals, this could be problematic in the aquarium if nitrate, phosphate, and other DOC's contribute to a higher bioload, bacteria count, etc.

Again, though,  I think we need to contemplate the difference between water "quality" as expressed by the measure of compounds like nitrate and phosphate, and  visual clarity.

My hypothesis:

Our aesthetic "upbringing" in the hobby seems to push us towards crystal clear water, regardless of whether or not it's "tinted" or not. 

A definite "clear water bias!"

And think about it: You can have absolutely horrifically toxic levels of ammonia, dissolved heavy metals, etc. in water that is "invisible", and have perfectly beautiful parameters in water that is heavily tinted and even a bit turbid. That's why the aquarium "mythology" which suggested that blackwater tanks were somehow "dirtier" than "blue water" tanks used to drive me crazy.

It doesn't bother me anymore.

Color alone is not indicative of water quality for aquarium purposes, nor is "turbidity." Sure, by municipal drinking water standards, color and clarity are important, and can indicate a number of potential issues...But we're not talking about drinking water here, are we?

No, we aren't! 

Those of us in the community of blackwater, botanical-style aquarists seek out tint and "body" in our water...while the rest of the aquatic world- well, they just sort of... freak the fuck out about that, huh?

Our aesthetic "upbringing" in the hobby seems to push us towards "crystal clear water", regardless of whether or not it's "tinted" or not. And think about it: You can have absolutely horrifically toxic levels of ammonia, dissolved heavy metals, etc. in water that is "invisible", and have perfectly beautiful parameters in water that is heavily tinted and even a bit turbid.

And water in a botanical-style aquarium is almost never crystal clear and transparent. Of course, it can be rendered such with the use of fine mechanical (like polyester filter pads, ceramic "noodles, etc.) or chemical media, such as activated carbon, or synthetic materials such as the much-loved Seachm Purigen.

In my personal aquariums, and in many of the really great natural-looking blackwater aquariums I see the water is dark, almost turbid or "soupy" as one of my fellow blackwater/botanical-style aquarium geeks refers to it. You might see the faintest hint of "stuff" in the water...perhaps a bit of fines from leaves breaking down, some dislodged biofilms, pieces of leaves, etc. Just like in Nature.

Chemically, my water typically has virtually undetectable nitrate and phosphate levels...A solid "clean" by aquarium standards.

But, yeah- it's "soupy"-looking...

One of my good friends calls this "flavor"- which sort of makes me laugh every time I hear it...but it seems to be an apt descriptor, huh?

It's important, when passing judgement on, or evaluating the concept of botanicals and blackwater in aquariums, to remember this. Look,"crystal-clear water" is absolutely desirable for 98% of all aquariums out there- but not always "realistic", in terms of how closely the tank replicates the natural environment.

And that's perfectly okay.

Because some of us simply love the "flavor!"

Stay thoughtful. Stay curious. Stay resourceful. Stay diligent...

And Stay Wet.


Scott Fellman

Tannin Aquatics 



October 30, 2020


When you're stuck.

It happens to every hobbyist from time to time.

You get stuck. 

You get a bit "winded.."

You run out of creative energy, or perhaps reach a mental state where you're not able to think about- let alone, execute on some of your  big ideas.

Ive been in that rut before. In fact, not too long ago. I let stuff frustrate and stymie me: "That tank is too small!" "That piece of wood can't work in this shaped tank!" "I can't hide the damn filter!"

Shit like that. I even have common "themes"- often revolving around stuff that I should be able to just look beyond. But I often can't, and it bums me out.

Seeing stuff like filters and other hardware that I can't conceal well drives me crazy to no end. And I really hate the limitations of some setups. I will have this great idea, get it going...and then bail out on it after a week or two, because I simply can't get it to do what I want, lol.

Sound familiar to you? Or, likely, this sort of "tantrum" thing is just me.

What to do?

I have learned to go back to the basics of what moves me.

Keep things very simple. Don/t overthink everything.

And don't start out with a setup that you know will frustrate you.

And there is another thing you can do:

Think like a beginner.

Perhaps the outright beginner in the hobby knows something that we don't.

I think I- we- that is, more "advanced" hobbyists...know too much. This knowledge sometimes works against us. We overthink, over-plan, over-visualize.

We expect too much from some stuff.


And I don't mean that from an arrogant perspective or anything.

I think that I, like so many hobbyists at my level of experience, tend to overthink every aspect of the aquarium hobby, particularly during the new tank startup phase, rather than just letting myself enjoy the moment- the wonder, and the awe that comes from doing something special, beautiful, and, let's face it- incredibly cool!

I mean, setting up a legit slice of Nature in your own home?

This IS something amazing, huh? 

Something that nine-tenths of the world will never get to experience or even comprehend.

So perhaps- just maybe...we know too much.


We understand all of this stuff. Or, we think that we do...And it puts "shackles" on us.

We experienced it many times over the years, and have watched- and even reassured- others that "All of this is normal" and to, "Just be patient and it will pass..."

You know- "aquarium stuff."

Outright beginners actually have it much easier in this regard, I think.

They aren't bound by the same expectations that we are bound by. It's kind of liberating!

And they take joy in just...having access to this wonderful underwater world.

I mean, when just having a glass or acrylic box of  freshwater or saltwater in your home is a novelty- a cause for rejoicing! You tend to live in a bubble of gentle "ignorance" (eeehw- that's kind of harsh)- okay, let's call it "blissful lack of awareness about some things" that some of this stuff really sucks...

And that's actually a beautiful thing- because a beginner is taken by the sheer wonder- and joy of it all.

They don't stress out about stuff like algal films, detritus on the substrate, micro bubbles and the occasional falling piece of wood in their aquascape. They're not worried about that yucky algae, or surface film, or any other of a dozen minutiae like we are, because they don't KNOW that it can linger a long, long time if you don't manage the tank correctly at this phase.

They're not "handcuffed" by their past experiences and the knowledge of having set up dozens of tanks over the years. Rather, they're just stoked as fuck by the thought of Glowlight Tetras, Amano Shrimp, Glass Catfish, and ultra-common Bettas taking up residence in the new little utopian aquatic microhabitat they just set up in their New York City apartment!

That's amazing.

When we're stuck, I think it's entirely possible to release ourselves from the "burden" of our own experience, and to allow ourselves to enjoy every aspect of this great hobby, free from preconception or prejudices. To just make quick  easy decisions based on what our research- gut, or yeah- I suppose, experience- tells us is the "right" thing to do, then letting stuff happen.

In other words, taking control of the influence that our own experience provides, rather than allowing it to taint our whole journey with doubt, dogma, second-guessing, and over-analysis of every single aspect.

It's liberating.

And relaxing.

Embracing the sheer joy of being a beginner. Again.

Sometimes, it's okay to look backwards. 

It might just propel you forwards in ways you never even imagined it would.

Stay relaxed. Stay engaged. Stay thoughtful...but not too much.

And Stay Wet.


Scott Fellman

Tannin Aquatics 

October 29, 2020


A deeper dive into the roots...

The  materials that we work with are our literal "palette", and they are more than just “set pieces” in our aquariums. They're also important for the function that they bring. The irony, as I see it, is that the greater aquascaping world more often than not simply fails to demonstrate, or even acknowledge in their work, the relationship between land and water, when the bulk of the materials used in aquascapes are of terrestrial origin. 

What a strange disconnect!

And NO, being "inspired by" a mountain, or doing a "diorama-style" 'scape replicating a "cloud forest" using aquatic moss on glued-together Spiderwood pieces is NOT highlighting this relationship! 😆 


The real land/water relationship is far different. It's more about soils, fallen trees, leaves, and root tangles. and further still, it's about epiphytic growth, and the foraging opportunities that they bring to our fishes.


We talk a lot about "microhabitats" in Nature; little areas of tropical habitats where unique physical, environmental and biological characteristics converge based on a set of factors found in the locale. Factors which determine not only how they look, but how they function, as well.

And we can replicate many of them with unique natural materials.

Now, small root bundles and twigs are not traditionally items you can find at the local fish store or online. I mean, you can, but there hasn't been a huge amount of demand for them in the greater aquascaping world lately...although my 'scape scene contacts tell me that twigs are becoming more and more popular with serious aquascapers for "detailed work" this bodes well for those of us with less artistic, more functional intentions! Apparently, if the more superficial sectors of the hobby create demand, the supply seems to follow..😆

Of course, we've been playing with these materials for years, for completely different reasons, because we are always approaching this stuff from a different angle.

And that "angle" is function. And the "muse" is Nature.

In flooded forests, roots are generally found in the very top layers of the soil, where the most minerals are. In fact, in some areas, studies indicated that as much as 99% of the root mass in these habitats was in the top 20cm of substrate! Low nutrient availability in the Amazonian forests is partially the reason for this. And since much of that root mass becomes submerged during seasonal inundation, it becomes obvious that this is a unique habitat.

So, ecological reasons aside, what are some things we as hobbyists can take away from this?  

We can embrace the fact that most of these finer materials will function in our aquairums as they do in Nature, sequestering sediments, retaining substrate, and recruiting epiphytic materials which fishes will forage, hide, and spawn among.

You can use a lot of materials to create a very dense look of tangled root structures extending into the water. For example, Melastoma roots have a perfect, delicate structure, and when combined with other, smaller wood pieces of materials create a very unique, realistic look.


The nice thing about a tangled mix of roots is that it not only creates a unique aesthetic- it instantly creates a fascinating replication of a unique natural habitat for fishes. And of course, we botanical-style aquarists are in a unique position to experiment with- and reap the befits of- these amazing natural materials.

In an aquarium set up to take advantage of these materials and their function, as the roots begin to soften and ultimately break down, they will foster microbial growth, biofilms, and fungal growths- all of which will provide supplemental foods for the resident fishes...just like what happens in Nature. 

Fungal growth, biofilms, and small crustaceans/microorganisms will live in the tangled matrix of small roots with enormous surface area. This has the dual advantage of functioning not only as a producer of supplemental food sources, but as a natural nutrient processing "facility" in the aquarium. This is a huge and important benefit provided by this type of assemblage.

Roots find their way into aquatic systems because..well- the aquatic system usually finds THEM! Areas of grasslands or varzea/igapo forest become flooded during seasonal inundations, and suddenly, the terrestrial habitat is transformed into a rich, productive- and unique-looking aquatic habitat, brimming with life.

Another absolutely perfect example of the intricate relationship between land and water that you simply won't get to truly appreciate if you don't allow those areas of biocover to accumulate. 

So, yeah, we can deliberately and easily create what, in Nature occurs by  happenstance. 

Big takeaway here: The thing that is fascinating about roots is that they function in our aquariums just like they do in Nature. Utilizing these materials in our aquariums is an easy, interesting way that we can replicate and study this unique microhabitat.  

You'll get to take a good, serious look at the elegance and function of these amazing natural ecological niches, which often go unnoticed by all but the most astute observers in the wild...right from the dry comfort of you own home.

Even in a more "aesthetic focused" display, roots can be allowed to accumulate the aforementioned epiphytic materials and to sequester sediments, to the advantage of our fishes, and to the delight of our senses!

I hope today's deeper dive into the roots gives you a bit more incentive, inspiration, and motivation to use readily-available materials to create unique and compelling aquatic habitats in your own home.

Say inspired. Stay fascinated. Stay engaged. Stay creative...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

October 28, 2020


I did a thing..

I did something the other day that a lot of people might think is kind of crazy.

I declined tp judge one of the Country's most prestigious aquascaping contests. I mean, yeah, it was a real honor being asked, and I was in some good company. I initially gave a sort of uncomfortable, almost tacit agreement to take part. And then, after literally wrestling with it for several nights, I woke up one early morning and was like, "What the fuck are you doing, Fellman? You can;'t judge a contest. It's not who you are, or what you even believe in!"

Yeah, I realized that, despite the great honor of being asked to judge a contest, that it's simply not what I am made of to be a judge. I have spent the better part of the last 20 years encouraging and cajoling hobbyists to be their best- to express their individuality, enthusiasm, and love for the hobby in ways that make their hearts sing.

I'm a cheerleader. A provocateur. An instigator, a motivator, and a fan. And apparently, an irreverent maverick of sorts, right?

I'm not judge material.

So why the hell would I want to stare at a bunch of people's hard work, dedication, and emotion, created with love and hope- and then pronounce judgment upon them...As if I have some divine authority; or as if I'm some anointed arbiter of taste.

I'm not. I feel bad that I even sort of nodded to the idea.

I spend much time on this blog and elsewhere railing on aquascaping contests, decrying the format, arrogance of the judges, the contest "culture", and the very notion that certain people are "winners", while others are not.

Yeah, I despise contests and contest culture. I'd definitely but heads with the other judges.  I hate rules. It would have made me wildly unpopular. It would have been really ugly. What the fuck was I thinking even entertaining the idea?  It was uncool of me, and intellectually dishonest, at the very least.

Now, let me be clear about something:

Now sure, I see a lot of aquariums that I like. And I see things that make me want to laugh, or worse.If people ask for constructive criticism, I'll give it to them, but it's based upon MY personal tastes, experience, and philosophies.

Judging a contest, to me, goes one step further than I'd like. A huge step, really. It's using some arbitrary rules to declare that someone else's work is better than..someone else's. 

I was to judge a biotope division. That's like having a vegetarian judging a barbecue contest.

You know how I feel about biotope contests, in particular. And you know my thinking about function of an aquarium over aesthetics and almost everything else. I'd likely cause huge friction between myself and fellow judges, and piss off a lot of entrants. Why? Because I'd be a lot more excited by the lady who's tank has a pile of detritus and decomposing leaves over her driftwood, than I would about the brilliantly crafted, highly stylized, intricately researched, yet (IMHO) oddly pretencious aquariums which seem to dominate that scene.

I would truly be the odd man out.

"We get it. You didn't;'t want to do the contest. You don't like them. Okay. Then bow out gracefully, Fellman, and shut the fuck up already!"

Fair point. However, you can simply navigate away from this page if you don[t want to read more. This is THERAPY for me, okay?

We've been talking a bout a contest for years. The problem is, I hate them. Our contest would be specialized, and more of an exhibition than anything else. I suppose I'd rather have our community decide on things like, "Most inspirational", "Most Unique", "Most representative of a functional natural habitat", "Longest Continuous setup", "stuff like that. No 1st, 2nd, 3rd place.

That's not me. 

Would I have some standards?

Of course. One would be that if you give a name to your work, you'd be banned for life from entering our exhibition! No "Fresh Wind of Spring" or "Mountains of Life." This is not a goddam piece of art.  It's not a diorama. It's an aquarium.

And no fucking essay on the geographic coordinates of the place your replicating ion your tank. No highbrow video production of the fish dancing through leaf litter necessary. How does your tank run? Are the fishes happy? What kinds of function do you embrace? What ideas can you share? How will this inspire others?

Alright, I'm literally beating the shit out of this. I'm coming across kind of angry and weird, lol.

But it feels really good to get this off my chest. Thanks for listening!

Gotta think of some ideas for MY next tank...just because! 

Yeah, I'm no judge. 

I'm a fish geek. That's all I am. And damn proud of it.

SO, I did a thing. And bowed out, to do what I think I do best.

That's something for me to celebrate.

Stay true to yourselves. Stay brave. Stay creative. Stay supportive. Stay inspirational...

And Stay Wet.


Scott Fellman

Tannin Aquatics 






October 27, 2020


A rebel without a clue?

One of the more satisfying side benefits of creating Tannin Aquatics is that I have been able to share my ideas with a pretty wide audience via this blog, the podcast, club speaking engagements, and magazine articles. It's neat to share my  point of view and philosophy on the aquarium hobby!

Now, something that I hear a lot is that I am sort of a "rebel" or even a "maverick" of sorts, giving my opinion on ideas, and questioning things that we've taken for granted in the hobby for generations; compelling others to try new and different approaches, and to lead by example. 

I hardly see that as "rebellious."

I had a most "conventional" aquarium hobby pedigree. My dad was a fish geek, who was obsessed with guppies. I had my aquarium when I was around 4 years old. My dad was a product of the "Golden Age" of the aquarium hobby, having gotten his start in the early sixties. I learned to read by picking through my dad's dog-eared copies of Innes' Exotic Aquarium Fishes, Guppies by Axelrod, Wiltern et al., and lots of other classic books on guppies and aquarium care. I was obsessed with them!

There was- and IS- enormous wisdom in those classic books. I spend many happy hours playing with all sorts of "old school" ideas gleaned from those books. I loved the romantic descriptions of fishes and aquarium ideas in Innes' book and in the writings of Axelrod and others. As I accumulated my own library over the years, it was filled with a lot of those classics and more, with widely varying ideas.

So, where did the "rebel" part come in?

I'm not sure.

I think that it came to being because, after decades in the hobby, I saw that some things were being done "just because", without questioning, modifying, or expanding. The hobby seemed to be stagnating in some areas.  And I spoke about them. ruminated about ways to move things along. To improve stuff. Offer different ways of doing things. 

Is that really "rebelliousness?"

I don't know. 

I admit that we do push some unusual ideas now and again...but they're inspired by Nature as it is, not by some fanciful, curated, sterilized,  and "pasteurized" version that we have in our fantasies.

What I do know is the I was sick and tired of seeing really talented hobbyists simply "mailing it in", and doing stuff a certain way without question, simply because "that's the way it is done- and it works." And then, being downright arrogant and, dare I say, "asshole-ish" about it. Like, declaring that there way was THE only way, and that anything against their way of thinking was some sort of transgression....because it works. Why question it? Dogmatic to the extreme.

THAT is exactly whyI question stuff. I hate arrogance for the sake of being arrogant.

And you should, too.

When we started Tannin in 2015, the first order of business was to quantify the very thing that we believed in, and worked with. We utilized the term "botanical-style" to describe the top of aquariums that we favor. It was important to give this approach a descriptor.

As many of you have pointed out, if you search prior to 2015, the term "botanical" was simply not used to describe this stuff. You had "blackwater aquariums", which was a rather tightly focused descriptor, and it only describes some of what we do.

That was just the start.

Our brand colors are browns and golds and earth tones. We eschew the usual "web vomit" rainbow hues found in most aquarium branding, because that's only part of what Nature offers up.

Is THAT rebellious?

I don't think so. 

We embrace leaves, wood, substrate, and the impact on the water that they bring...Earthy ambience, as opposed to crystal clear, prismatic brightness. A different look, too.

Is That being rebellious?


We had to share our ideas, techniques, and educate. A huge responsibility. We all bear this. And of course, the idea of dispelling misinformation about this approach occupied- and STILL occupies- a large amount of our focus. There's so much misinformation and even lack of information out there. And the idea of pushing back against misinformation actually labeled me a "rebel" in some corners- which makes me laugh.

We have to question ideas and technique.


We HAVE to start looking at Nature AS IT REALLY IS as an influence. It's easy to fall in love with a look- we all have. But when we simply look at stuff from such a superficial lens, it sells us short. And I hate the hobby selling itself short. I hate us falling back on, "We do this because that's the way it's been done. And it works."

Of course, it works. But can't it work better? 

Can't we look at stuff like detritus, biofilms, turbidity, and tint- and understand exactly how this stuff is not only beautiful to look at, but elegant and efficient in its function. And how we can't be afraid of stuff because it looks contrary to what we've been taught in the hobby to be "healthy."

It's what Nature does. And has done for untold eons.

Look closely at Nature, and ask why things are the way they are. And attempt to replicate Her processes; the "look", different as it may be- will follow.

Thinking that way is not "rebellious."

It's simply progressive. It's evolutionary.

And look, some ideas or approaches that you explore and share are not well received. Or perhaps, just maybe- they're wrong. Accept that snd move on. Part of being a progressive person in the hobby is to accept that you might be incorrect, or that your ideas might be "off" now and then. I'm okay with that.  You should be, too.

Humility is a good thing to embrace in the hobby.

Don't be close minded. Look at things that are done a certain way, and if you see a better way- a more beneficial way- experiment, improve upon them, and share. And accept the good and the bad. Embrace the ephemeral.

We push a lot of unusual ideas and approaches here at Tannin Aquatics. They're not the best way- but they are a different way. And often, they fly in the face of the existing, commonly accepted way of doing stuff. Their look and function defy convention at times. And other times, they embrace things hobbyists have done for generations; perhaps stuff forgotten or dismissed in their day.

Is that being rebellious?


It's not rebellious to look at things differently. To question the status quo for the sake of moving the state of the art forward. It's not rebellious to look to our hobby's glorious past to evolve it to a new and exciting future.

So, if you're labeled a rebel or "disruptor" or whatever because you look at stuff differently, perhaps because you try a slightly different approach- and believe in what you do enough to take the criticisms- just put your head down and keep doing what you believe in.

Push the hobby forward by doing. Differently.

Share. Educate. Experiment. Question. Accept blame when it's deserved, don't get too high on any accolades you might receive along the way.

And if maybe, at some point, you want to be just a bit provocative from time to time- to make some noise...Raise a bit of hell- I say go for it. 😆

The hobby needs some of that, too.

Is THAT being rebellious?

 Well, maybe. But it's also kind of fun.

Okay, I might be a rebel. But I'm clueless about that part. You should be, too. Just be you. Celebrate, create. Love.

Stay curious. Stay thoughtful. Stay bold. Stay generous...

And Stay Wet.


Scott Fellman

Tannin Aquatics