May 10, 2022


The part where Scott is on someone else's podcast...

As those of you who read and listen to the podcast version of "The Tint" know, I can talk. A lot. And it's usually about weird stuff. So, when I'm asked to appear on someone else's podcast, I do my best reign it in a bit, lol.

Last week, I was guest on the popular "RumbleFish Podcast", and the host, Paula Underwater, and I had a great conversation on different aspects of the botanical method approach and its place in the aquarium hobby. Something which we don't always talk about enough here!

So, check out and support this very good podcast - they have a lot of cool guests! And of course, give a listen to the episode that I'm in!

Stay informed...Stay Wet!


Scott Fellman

Tannin Aquatics 

Perpetual darkness...

Okay, that was an admittedly "dark"-sounding title, but it's perfectly appropriate for today's topic...How to get- and keep- your water as tinted as possible. Or, at least, what materials would do the best job in terms of "color production."

We as a group are kind of obsessed with this.

And yeah, it's a good question!

Now, first off- let's all remember that the color of the water has absolutely NO relationship to its pH or carbonate hardness. It just doesn't. You can have water that looks super dark brown, yet has a pH of 8.5 or whatever. And conversely, it's just as possible to have crystal clear blue-white water that's soft, and has a pH of 4.5. We have to get beyond the social media-style "blackwater" definition, which seems to be, "If the water is tinted, it's a blackwater aquarium!"

Now, look, if you just want the nice color but could care less about the pH and hardness, that's fine. For the benefit of the hobby as a whole, please don't perpetuate the confusing narrative about blackwater aquariums by telling others that you have "blackwater." You have a "tinted" aquairum. 

And that's just fine.

So, yeah-I'm not going to launch into a long drawn out description today about how ecologists define "blackwater" and what specific chemical characteristics make it up- we've covered it enough over the can deep dive here or elsewhere to get that. 

Okay, micro-rant over. Let's get back to the topic.

Remember, this piece is not about how to make blackwater...It's a little more superficial than's about creating an aquarium with color and maintaining it. 

First off, one of the "keys" to getting your color that lovely brown is to select the right types and quantities of botanical materials to assist. Now, I'll be the very first to raise my hand and call BS on anyone who claims to have a perfect "recipe" for how many Catappa leaves per liter or whatever you must use to achieve a specific color. Sure, you could come up with some generic recommendations, but they're not always applicable to every tank or situation.

Yes...there are simply so many variables in the equation- many which we probably haven't even considered yet-that it would be simply guessing. Just like Nature, to some extent...

What I can do is recommend some materials which we have found over the years to generally impart the most reliable and significant color to water. In no particular order, I'll give you my thought on a few of my personal faves. There are a lot more, but these are some that consistently show up on my "fave" list. 


Yep, you heard me. One of the very best sources of tint-producing tannins in our aquariums is wood. I've told you many times, wood imparts tannins, lignin, and all sorts of other "stuff" from the exterior surfaces and all of those nooks and crannies that we love so much into the water. 

Ahh...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 wood. I mean- what's the big deal?

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

The reality, though, as you probably have surmised, is that wood will continue to leach tannins to a certain extent 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 humic substances that are known to have health benefits for fishes.

Some wood types, like Mangrove ( a wood we don't have at the moment), 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 Manzanita wood, seem to be really "dirty", and release a lot of materials over long periods of time. All will recruit fungal growths and bacterial biofilms.

And  the biocover on the wood is a unique functional aesthetic, too, as we rant on and on about here!


I'm a huge fan of tree bark to impart not only color, but beneficial tannins into the water. Because of its composition and structure, bark tends to last a very long time when submerged, and tends to impart a lot of color to the water over the long term.

And to be quite honest, almost all of the bark products we've played with over the years seem to work equally as well. The real difference in bark is the "form factor" (appearance) and the color that they impart to the water over time. Some, such as Red Mangrove bark or Cutch bark, will impart a much deeper, reddish-brown tint to the water than say, an equal quantity of catappa bark. And our soon-to-be-released Ichnocarpus bark really packs in this reddish brown color! You're gonna love this stuff! 

Ounce for ounce, gram for gram, I've always felt that various types of bark always impart the most color to the water over almost any other materials.

"Skyfruit Pods" 

These are very interesting, woody pods, derived from the outer "valve" of the fruit of the Swietenia macrophylla tree, which hails from a wide range of tropical locales (although native to Brazil), and are just the sort of thing you'd find floating or submerged in a tropical jungle stream. Often called "Skyfruit" by locals in the regions in which they're found because they hang from the trees- a name we fell in love with!

These botanicals can leach a terrific amount of tannins, akin to a similar-sized piece of Mopani wood or other driftwood. They are known to be full of flavonoids, saponins, and other humic substances, which have known positive health effects on fishes. Like bark, it lasts a good long time and recruits some biofilms and fungal growths for good measure.

Live Oak Leaves/Magnolia Leaves 

Despite their humble North American origins, these leaf types impart more color, ounce per ounce, than just about any of our fave tropical leaves. And they both last very long time...Like, I've had specimens of live oak leaves stay intact for several months!

It's really important to think of leaves as not just a "coloring agent" for your water, but as a sort of biological support mechanism for your burgeoning ecosystem. They actively recruit fungi, bacterial biofilms, and other microorganisms which enrich the overall aquatic environment in your tank.




Alder cones  (Aalnus glutinosa and Alnus incana)  and Birch cones (Betula occidentalis), have  been widely utilized by aquarium hobbyists in Europe for some time. Betta and ornamental shrimp breeders are fond of the tannins released into the water by these cones, and their alleged anti fungal and antibacterial properties. There has also been much study by hobbyists about the pH reduction attributes of these cones, too.

A study done a few years back by a Swedish hobbyist using from one to six cones in a glass containing about 10 ounces of tap water, with a starting ph of around 8.12, was able to affect a drop to 6.74 with one cone after about two weeks, 4.79 with 2 cones after two weeks, and an amazing 3.84 with 6 cones after the same time period! The biggest part of the drop in pH occurred in the first 12 hours after immersion of the cones!

Now, I'm the last guy to tell you that a bunch of cones is the perfect way to lower pH, but this and other hobby-level studies seem to have effectively have demonstrated their ability to drive pH down in "malleable" (soft) water...

 Coconut-based products (Coco Curls, "Fundo Tropical", "Substrato Fino")

There's something about coconuts...The materials which are derived from the husks of coconuts seem to produce a significant amount of tannins and impart color to the water. Of course, "Substrate Fino" and "Fundo Tropical" are smaller, or finer-textured materials which work primarily as "substrate enhancers", and not strictly as "color-producing agents", because there is an initial "burst", which subsides over time. 

Now, one of the novel applications for these finer botanical materials to take advantage of their color producing ability is to place them in a fine mesh filter bag and allow water to flow around or through them, like filter media. Essentially, a more sustainable alternative to the old peat moss trick...

Oak Twigs

For an interesting look and some nice color, I'm a big fan of oak twigs. Oak has a nice bark which imparts a deep brownish/yellow color to the water and it's quite distinctive. There is a reason why our  "Twenty Twigs" packs are pretty popular, and it's not just because you get a bunch of cool sticks!

When mixed with leaves and/or other botanical materials, not only do you get an incredible "framework" for a cool ecosystem, you get an incredible aesthetic as well!

Now, this is an absolutely cursory list.. I could have easily listed 10 or more items. No doubt, some of you hardcore enthusiasts are screaming at your screens now: "WTF Fellman, you didn't include_______!"

And of course, that's the beauty of natural materials...There are numerous options!

Another note on the colors to expect from various botanical materials. As you might suspect, many of the lighter colored ones will impart a correspondingly lighter tint to the water. And, some leaves, such as Guava or Loquat, also impart a  more yellowish or golden color to the water, as opposed to the brownish color which Jackfruit and Catappa are known for. 

A lot of you ask about things that impact how long the water retains it's tint.

This kind stuff is a big deal for us- I get it! Many hobbyists who have perhaps added some catappa leaves, "blackwater extracts", or rooibos tea to their water contact me asking  stuff like why the water doesn't stay tinted for more than a few days. Now, I'm flattered to be a sort of "clearing house" for this stuff, but I must confess, I don't have all the answers.

So, "Why doesn't my water stay tinted, Scott?"

Well, I admit I don't know. Well, not for certain, anyways!

I do, however, have some information, observations, and a bunch of ideas about this- any of which might be literally shot to pieces by someone with the proper scientific background. However, I can toss some of these seemingly uncoordinated facts out there to give our community some stuff to "chew on" as I offer my ideas up.

Now, perhaps it starts with the way we "administer" the color-producing tannins. 

Like, I personally think that utilizing leaves, bark, and seed pods is perhaps the best way to do this. I'm sure that you're hardly surprised, right? Well, it's NOT just because I sell these material for a living...It's because they are releasing tannins, humic substances, and other compounds into the water "full time" during their presence in the aquarium as they break down. A sort of "on-board" producer of these materials, with their own "half life" (for want of a better term!).

And, they also perform an ecological role, providing locations for numerous life forms (like fungal growths) surface area upon which to colonize. They become part of the ecosystem itself. A few squirts of "blackwater extracts" won't do that, right?

The continuous release of tint-producing compounds from botanical materials keeps things more-or-less constant. And, if you're part of the "school" which leaves your botanicals in your aquarium to completely break down, you're certainly getting maximum value out of them! And if you are continuously adding/replacing them with new ones as they completely or partially break down, you're actively replenishing and adding additional "tint-producing" capabilities to your system, right?

There is another way to "keep the tint" going in your tanks, and it's pretty easy. Now, those of you who know me and read my rambling or listen to "The Tint" podcast regularly know that I absolutely hate shortcuts and "hacks" in the aquarium hobby. I preach a long, patient game and letting stuff happen in its own time...

Nonetheless, there ARE some that you can employ that don't make you a complete loser, IMHO.😆

When you prepare your water for water changes, it's typically done a few days to a week in advance, so why not use this time to your advantage and "pre-tint" the water by steeping some leaves in it? Not only will it keep the "aesthetics" of your water ( can you believe we're even talking about "the aesthetics of water?") consistent (i.e.; tinted), it will already have humic substances and tannins dissolved into it, helping you keep a more stable system.

Obviously, you'd still check your pH and other parameters, but the addition of leaves to your replacement water is a great little "hack" that you should take advantage of. (Shit, I just recommended a "hack" to you...)

It's also a really good way to get the "look" and some of the benefits of blackwater for your system from the outset, especially for those of you heathens that like the color of blackwater and despise all of the decomposing leaves and seed pods and stuff!

So, if you're just setting up a brand new aquarium, and have some water set aside for the tank, why not use the time while it's aging to "pre-tint" it a bit, so you can have a nice dark look from day one? It's also great if you're setting up a tank for an aquascaping contest or  other same-day club event that would make it advantageous to have a tinted tank immediately.

I must confess that yet another one of the more common questions we receive here from hobbyists is, "How can I get the tint in my tank more quickly?"- and this is definitely one way!

How many botanicals to use to accomplish this?

Well, that's the million dollar question.

Who knows?

It all gets back to the (IMHO) absurd "recommendations" that have been proffered by vendors over the years recommending using "x" number of leaves, for example, per gallon/liter of water. There are simply far, far too many variables- ranging from starting water chem to pH to alkalinity, and dozens of others- which can affect the "equation" and make specific numbers unreliable at best. 

We did, too, in the early days of Tannin. And it was kind of stupid really. There just is no hard-and-fast answer to this. Every situation is different. You need to kind of go with your instinct. Go slowly. Evaluate the appearance of your water, the behaviors of the fishes...the pH, hardness, TDS, nitrate, phosphate, or other parameters that you like to test for.

It's really a matter of experimentation.

I'm a much bigger fan of "tinting" the water based on the materials in the aquarium. Letting Nature have at it. The botanicals will release their "contents" at a pace dictated by their environment. And, when they're "in situ", you have a sort of "on board" continuous release of tannins and humic substances based upon the decomposition rate of the materials you're using, the water chemistry, etc.

Replacement of botanicals, or addition of new ones, as we've pointed out many times, is largely a subjective thing, and the timing, frequency, and extent to which materials are removed or replaced is dependent upon multiple factors, ranging from base water chemistry to temperature, to the types of aquatic life you keep in the tank (ie; xylophores like certain Plecos, or strongly grazing fishes, like Headstanders, will degrade botanicals more quickly than in a tank full of characins and such).

(The part where Scott bashes the shit out of the idea of using "blackwater extracts" and Rooibos tea. This could get nasty!)

If you haven't heard of it before, there is this stuff called Rooibos tea, which, in addition to bing kind of tasty, has been a favored "tint hack" of many hobbyists for years. Without getting into all of the boring details, Rooibos tea is derived from the Aspalathus linearis plant, also known as "Red Bush" in South Africa and other parts of the world. 

(Rooibos, Aspalathus linearis.  Image by R.Dahlgr- used under CC-BY S.A. 2.5)

It's been used by fish people for a long time as a sort of instant "blackwater extract", and has a lot going for it for this purpose, I suppose. Rooibos tea does not contain caffeine, and and has low levels of tannin compared to black or green tea. And, like catappa leaves and other botnaicals, it contains polyphenols, like flavones, flavanols, aspalathin, etc. 

Hobbyists will simply steep it in their aquariums and get the color that they want, and impart some of these substances into their tank water. I mean, it's an easy process. Of course, like any other thing you add to your aquarium, including leaves and botanicals, it's never a bad idea to know the impact of what you're adding. 

Like using botanicals, utilizing Rooibos tea bags in your aquarium requires some thinking, that's all. 

The things that I personally dislike about using tea or so-called "blackwater extracts" are that you are simply going for an effect, without getting to embrace the functional aesthetics imparted by adding leaves, seed pods, etc. to your aquarium as part of its physical structure and ecology, and that there is no real way to determine how much you need to add to achieve______.

Obviously, the same could be said of botanicals, but we're not utilizing botanicals simply to create brown water or to target specific pH parameters, etc. We're trying to create an ecology that is similar to what you'd see in such habitats in Nature.

Yet, with tea or commercial blackwater extracts, you sort of miss out on replicating a little "slice of Nature" in your aquarium. The building of an ecosystem.  Which is why we call this the botanical method. It's not a "style" of aquascaping! And of course, it's fine if your goal is just to color the water, but it's more of an aesthetically-focused aquarium at that point.

I also understand that some people, like fish breeders who need bare bottom tanks or whatever- like to condition water without all of the leaves and twigs and nuts we love. They want the humic substances and tannins, but really don't need/want the actual leaves and other materials in their tanks.

And, when it comes to tea and these commercial extracts, I don't think the stuff lasts all that long. I personally believe that the tint-producing tannins in "tea" are potentially taken up quickly by substrate materials, filter media, etc. And unless you're keeping tea bags in your tank on a continuous basis, you'll always experience some "color loss" after some period of time.

Yes it works to impart some color and tannins. Creating infusions or extracts is useful, if you understand their purpose and limitations. They have a place in the hobby for sure.

It's why we got into the game with our botanical-based "Shade" products. We're currently sold out and are working with our supplier on a reformulated version. Seems as though we need to make a "darker" mix!

On the other hand, if you're trying to replicate the look and function (and maybe some of the parameters) of THIS:

You won't achieve it by using THIS:

It's simply another shortcut.

Not good or bad. Just a way to get the end "effect" faster, and without the other collateral benefits we discussed.

And look, I understand that we are all looking for the occasional shortcuts and easier ways to do stuff. And I realize that none of what we proffer here at Tannin is an absolute science. It's likely more of an "art" at this point, with a little science behind it.

Think about it: There is no current way available to the hobby to test for "x" types or amounts of tannins (of which there are hundreds of types) in aquariums.  I mean, there are tannin test kits, but they're used for wine making and such...Perhaps there is some tangential application for our purposes, but I'm not really sure what practical information. we could extract from the results.

And, I have not found a study thus far which analyzed wild habitats (say, Amazonia) for tannin concentrations and specific types, so we have no real model to go on.

The best we can do is create a reasonable facsimile of Nature.

And, in Naturę, a lot of the tint in blackwater environments comes from dissolved fulvic and humic acids from...soils. Yeah, geology is the key, IMHO, to truly "realistic" blackwater habitats. This is why I've been very picky on sourcing the materials and figuring out recipes for our NatureBase sediment substrates. They are intended to support these types of systems.

Understanding substrates and their role in both the physical environment and the ecology of our aquariums is still a wildly under-appreciated concept in the aquarium hobby, IMHO. We'll keep coming back to this in the future, I'm certain.

And keeping the water tinted is something that many botanical method aquarists are interested in. This wonderful "collateral benefit" of our approach is something that's easy to get addicted to!

Now, all of these ideas are okay to impart some color to your water. Some do more, as we've discussed ad nauseam. And none of them will work to full advantage if your aquarium is removing them as fast as you're imparting them into the water. So, go easy on chemical filtration media like carbon. I didn't say NOT to use them...Just don't use a ton of them! Use less than what the manufacturer recommends. 

What about plants?

Well, I have a theory about plants and tannins...

First off, as you know by now, you absolutely can keep plants in blackwater aquariums. We've talked about this a million times over the years. And yet,  interestingly, you can't always keep "blackwater conditions" (at least, color-wise) in planted aquariums! There has been much geeky discussion on this topic.

Tannin are interesting things. Think about this:

Tannins are known to bind up heavy metals and minerals. The roots of aquatic plants prefer to take up bound-up minerals and metals...So, another theory of mine is that heavily planted tanks do actually remove some of the visual "tint" (ie; the tannins) from the water via uptake from their roots. 

Make sense? Maybe?

Okay, I could go on and on all day throwing out all sorts of theories and unsubstantiated (via lab tests and rigorous studies, anyways) ideas on this topic...But I think I gave you enough here to get the party started. I encourage you to do some homework. We need to ask these questions to people who really understand the chemistry here. I think that there might be some good answers out there.

And, back to the "color thing" to close on here...

I admit, visual "tint" is probably THE single most superficial aspect of what we experience with botanical-method aquariums- but the most obvious, and likely the most impactful to the casual hobbyist or observer.

It's just as important to understand the collateral benefits of utilizing botanical materials- a subject we've discussed dozens of times here. However, in the end, it's the look of your aquarium that is what you have to experience each and every day, and if having an understanding of which materials can bring you the aesthetic experience you're after in a more effective way- well, then this is a worthwhile discussion, right?

I think that it is.

Stay curious. Stay resourceful. Stay enthusiastic. Stay observant. Stay appreciative. Stay tinted...

And Stay Wet.


Scott Fellman

Tannin Aquatics  

May 03, 2022


Welcoming the unexpected...and resisting the urge to overthink...

One of the great joys of the aquarium hobby is that, despite our careful planning, "stuff" can happen to our tanks that we didn't anticipate...And not all of it is bad!

We spend an awful lot of time worrying about every contingency, stressing over how our tanks will operate or why  "x" happened, despite our extensive planning to avoid such things. And often, whatever it was that happened wasn't all that "bad."- we as hobbyists just tend to classify anything which doesn't go exactly to plan as an "issue."

I was talking to one of my friends recently about what was going on in his cool fish room, and he was telling me that he was just looking to see what fishes were “breaking out”, which ones could be doing better, and which ones were in trouble. A cool, useful practice that many of us engage in with our tanks.

He reflected on the fact that, on any given day in a lot of fish rooms, you’ll find fishes or tanks that are kicking ass, some that could look better, and some that just declined for no apparent reason.


“No apparent reason…”

I find that expression intriguing.

Familiar words, actually. I hear them often when talking to fellow hobbyists who, when talking about the goings-on in their aquairums, will say things like, “…and they were looking great the other day, and today- they’re just failing to thrive for no apparent reason.” 

You see it on the forums- at least a dozen threads every day about “anomalous” fish losses. This is not a new thing. It’s not even an unusual thing. It happens. A lot. 

In a given community of organisms, all sorts of stuff happens from day to day.

Back when I co-owned a large coral propagation operation, with thousands of corals under our care, we needed to assess and get to the bottom of whatever went wrong- because if it spread, it could have jeopardized large amounts of our inventory. Not good when you make a living growing corals. Oh, sure, we had safeguards in place, but sometimes stuff slips through, and you need to attempt to find the root cause of the problem, lest it occur elsewhere in your facility.



Over the years, I’ve learned that there is ALWAYS a reason why fishes or corals struggle or die. We may not always find the ONE factor- the one thing that did it…But there is always a reason, or bunch of reasons- why the fishes or corals didn’t make it. It's not just "because..." The explanation may be beyond our ability to decipher, but it's out there. Stuff-good and bad- just doesn't happen for "no apparent reason."

On the other hand…sometimes, you just can't seem to pin it down, right? You go through the mental checklists of things that you do. Some change in the usual product additions, feedings, procedures, etc. You look at water parameters, search for trends. Look for one thing you did differently two days ago that could have been the trigger for the calamity…And still, the answer eludes you.

The unfortunate, unscientific, and altogether unsatisfying conclusion that we come up with after exhausting the obvious- and even the obscure- is often- the fish simply died for “no apparent reason.”


That sucks. It’s frustrating, because of course, there are reasons why the fishes died. Often, its more than one factor that contributed.

And you can’t find them. Can’t pin down the cause.

Without sounding like the proverbial broken record, this reinforces the usefulness of practices like regular water testing, because when tests are performed regularly and evaluated frequently, you’ll spot trends.

Trends are super important in aquarium management, aren’t they?

They help you see what direction your system is headed. They help you see if your parameters are stable, swinging all over, or just headed in one direction or another. Without getting too caught up in “big data”, you can get some good feeling for how your tank is doing by sifting through your test results from time to time. 

This seems obvious, but you'd be surprised how often many of us don't do this...

And there is no substitute at all for the simple, and often quite enjoyable- act of just looking at your aquarium. Every parameter is important, but if your tank looks like shit, does it really matter if phosphate is .04ppm or .08ppm? Your eyes are probably one of the best aquarium testing devices ever conceived…you just need to apply them regularly! In our busy lives, the surprisingly simple act of allocating the time to just look at our beautiful tanks sometimes eludes ironic is that?


So the altogether unsatisfying conclusion of this discussion? Sometimes you just can’t find the source of the decline in your aquarium, or why you lost that particular fish. Sometimes the data eludes us. 

There are a lot of “moving parts” in a typical aquarium, and the failure of any one of them may or may not trigger a problem…it can be frustrating ferreting out which of the 5 dozen possible things that could have gone wrong might have lead to the "problem" you experienced. And it's very easy to simply overthink; over-analyze everything. 

Just don't beat the shit out of yourself by overthinking stuff. 

I think there is something about tropical fish and aquariums in general that invites over-thinking" stuff.

Yeah, we've kinda made a damn art form of it.

Cases in point:

Algae blooms.

We analyze every possible cause, sometimes embracing on multiple courses of action, and then ultimately realize that it boils down to the fact that we had excessive nutrients in our source water, something that could have been addressed first, and with appropriate actions taken, would have solved the problem much faster!

Sometimes, we attack the problem, but spend valuable time on the wrong part of it.

Disease outbreaks? 

I get a lot of emails from aquarists trying to figure out how the new fish caused their disease outbreak ("It appeared healthy, and my LFS quarantines all new fishes"), when the reality is that it DID, and that it would be far better focusing on the solution- that being, removing the fishes to a treatment aquarium, etc.- and for the future, instituting a rigid quarantine protocol for future additions. 

We already know the answers to some things...I think that we just sometimes don't like to hear them. We know that we need to quarantine new fishes for the maximum protection. We just don't always want to execute on that...

We know how to solve most of the problems that we encounter in the hobby. As a group, we're actually pretty damn good at aquarium keeping. A century or so of "modern" aquarium keeping experience has definitely paid off.

Yet, we sometimes make things more complicated than we need to, adding layers of complexity to problems that, although important or critical, can be more than adequately addressed by simply DOING something we already know how to do.

Water quality is important in closed systems. Water exchanges are simple, economical, and probably one of the very best thing we can do as aquarists to keep captive aquatic animals healthy for long periods of time. We know this...

Many aquarists just absolutely despise them, and will go to great (and often expensive) lengths to avoid doing them, or to make them less onerous. Yet, an entire cottage industry of gadgets, procedures, etc. exists around the premise of "Eliminates water changes!" or "Reduces water changes!"

I mean, how many hobbyists do you know who developed "automatic water change" systems for their aquariums, with a lot of experimentation, complexity, labor, expense- and sometimes, consequences? In fact, I know at least two hobbyists who had to submit homeowner's insurance claims for damage caused by an "automatic water change system" that they designed and built!

Why not just perform a water exchange the old fashioned way? A siphon hose and a bucket can do wonders. It's not even that big a deal, gets you intimately involved with your tank, and doesn't take all that much time.

I think that even scientists tend to "reinvent the wheel" and make things related to aquariums more complicated than they have to sometimes!

I saw a segment on one of those cable news magazine shows not too long ago about how scientists were working on this "novel way to help restore coral reefs that were threatened by global warming, etc.", and how they went to all of this effort to collect coral larvae, let them settle in the lab, then attach the young coral to rock on a reef. Collecting coral larvae is difficult, time consuming, and resource-draining.

I couldn't help but reflect upon the fact that we, as hobbyists, have been fragmenting and propagating corals for some 3 decades now, both at a personal and commercial level. Literally cutting them into fragments and gluing them to ceramic plugs or rocks...and we grow them by the tens of thousands all over the world. Coral farming is not some esoteric theoretical thing. It's being done every day on a practical level.

I remember watching this and was like, "Guys, if you need coral to restore a coral reef, just visit a local reef club meeting! They'll hook you up. Why are you making it so complicated?"


Now, granted, there's a bit more to it than that, and I cannot downplay the achievements of the scientists involved...collecting and studying larvae and all...but man, if you want to restore a reef...quickly, why not just make some frags?

And the best part of the segment was that there was an admission by a scientist working on the project who said something to the effect that, "As scientists, we're great at studying corals, but not great at growing them." So what did they do? They turned to aquarists! ( I knew they'd get there eventually!)

It's also long been a reef hobby joke that scientific institutions generally have reef aquariums in their facilities that are, ahem, "less impressive" than an average home aquarium!

Granted, there are many awesome reef tanks at public aquariums, but generally, to a hobbyist, a surprisingly large number of them are underwhelming, despite the obvious availability of manpower, equipment, and resources available for the institutions to create and  maintain them. My advice? Just call a reef club, tell 'em what you need, and be done with it already! They'll hook you up! You don't think hobbyists would literally crawl all over each other to be involved in a project like that?

I know, this is a harsh, generalized, and sort of unfair assessment...But yeah, it serves as an example of how aquarists often tend to overthink aquarium-related stuff, even at "higher levels."

As aquarium hobbyists, think of the time, money, aggravation, and energy that we can save if we just focus on the actual problem, and don't over think ways to solve it.

In fact, sometimes, it involves NOT micro-managing every aspect; controlling each and every aspect of what goes on in our tanks. Sometimes, just sitting back and letting things unfold is the very best strategy.

As a lifelong hobbyist, I've personally been through periods of time when I couldn't devote as much time  to my beloved fish tanks...Yet I always had one- fresh, salt, or otherwise. It's just not "home" unless you hear the reassuring popping of bubbles, whirring of pumps, and see the beautiful reflections caused by the interplay of light and moving water.

Of course, there were a number of times that, for one reason or another, I simply let my tanks "run themselves", save an occasional water change or filter media cleaning, and of course, regular feeding (that consisted of tossing in a few flakes or pellets, or whatever was on hand at the time).

You know, putting Mother Nature in control!

A particularly fond memory of this type of  "practice" comes from my Senior year in high school, when I was seriously into breeding killifishes (in addition to keeping saltwater, cichlids, tetras, and of course, the usual high school pursuits of girls, sports, and socializing). As a junior AKA member, I obtained a group of the "Clown Killie", Epiplatys annulatus Monroviae, and was determined to breed the little buggers.

Of course, this species always had a reputation for being just a bit of a challenge, requiring careful care, feeding, and a fair measure of patience. As a busy kid, I had little patience (although more than the average high school guy- after all, I was a fish geek!), so I was delighted to learn that these fishes were thought to fare better in "permanent" and "natural" setups (fish geek code for "set and forget", IMHO).

So of course, in a rather strange twist, I kind of thought that this species was a perfect fish for my busy lifestyle at the time!

I set up 2 pairs and a few extra females in a 2.5 gallon tank, planted (well, packed) with Water Sprite, Hygrophila, and Rotala. Given moderate light from a small fixture, and a sponge filter providing filtration/circulation, this tank looked good and ran just fine with little intervention on my part. In fact, I'm embarrassed to admit that I would sometimes go a week or more without some much as looking at the tank long enough to toss some food in there.


One day (I think it was during Spring Break), I actually took the time to really stare into the tank, to see what was going on...Sure enough, upon close examination, I saw several tiny fry flitting in and among the Rotala! I was elated! Rather than panic and start hatching brine shrimp, I made the very mature and level-headed decision to simply...leave them alone, as I had been doing for months.

I resisted the temptation to net them out, power feed them, and otherwise intervene. I reasoned that I could hardly do better than what they were apparently being provided by Nature, as they have done successfully for eons. ( like, this is a big part of my current philosophy on aquarium keeping!)

I ultimately ended up with a pretty stable population of around 12-15 individuals, in a tank I "maintained" for around 3-4 years. Ironically, the difficulties started when I had the time to really get into "taking care" of the fishes, and took more initiative and control of the breeding.

I ultimately slowly lost the entire colony. Sad.

But a valuable lesson. Sometimes, what we would classify as "benign neglect" is actually the best thing we could do..the closest imitation to Nature that we can offer fishes in captive environments! 

Part of what makes the “job” of the hobbyist so enjoyable is the search for knowledge…the camaraderie that arises from our community putting their heads together to answer great questions…and sometimes, just to share "war stories" with fellow fish geeks. To learn and grow together as a community.

And occasionally, to laugh at our own absurdities. 

Not long ago, I recall walking into my office early one morning, and I immediately was taken aback. I apparently had accidentally messed with the time settings on a lighting app for one of my LED lights while tweaking a color setting (cause, that's what fish geeks do, right?), and caused the light to say on almost 20 hours before I realized that I messed it up.

No biggie, right?

It happens.

Except that I had recently added some cool wild fishes to the tank, after weeks of careful acclimation and quarantine...and then- THIS had to happen, know where I'm going with this?

This is what was going through my mind:

"Omigod, the fishes didn't get any dark period...they've been seriously stressed..."

Now, some of you will say that this wouldn't bother you- but you're totally lying! It would bother the shit out of you, too! I know it would,'cause you're a fish geek. Being bothered about ridiculous stuff is part of what we do!

Never mind that the "delicate" wild fishes had endured the rigors of being captured, traveling to a collection facility, then. a wholesaler, then on to my, THAT shit wasn't stressful enough, right?

And goes what? They freaking lived!


Of course, I relayed this concern to my wife later in the day, when we touched base and asked each other how are days were progressing.

To which my wife, who's absolutely not a fish geek, yet ever the pragmatist, noted, "You know, Scott, sometimes, unexpected things happen in the Amazon."


She was on to something there!

She was right. Everything in Nature, like in society, is not a linear, routine, predictable path. Shit happens.

Yet, we worry, and panic, and obsess...

And it's not just me who freaks out about stuff like this. I know for a fact...

We ALL do. It's like a fish-geek thing.

I think, that as hobbyists, we tend to get caught up in every little minute detail of the little worlds we've created for our fishes- so much so that we often forget the one underlying truth about them: They're living creatures, which have evolved over eons to adapt to and deal with changes in their environment-big and small...or even insignificant, like an excessive amount of light one evening. 

I mean, there must have been some natural precedent for this, right? Some atmospheric phenomenon- or combination of phenomenon-which rendered the night sky inordinately bright one evening at some point in the long history of the world?

Yeah. Exactly.

Think about it more for a second. 

I think that this high level of concern-this "overkill", if you will, on the part of all hobbyists is based on the fact that we take great pains to assure that we've created perfect little captive environments for our fishes, and do everything we can to keep them stable and consistent.

When something out of the ordinary happens- a pump fails, a heater sticks in the "on" position, we forget to feed, etc.- we tend to get a little bit, oh I dunno-...crazy, maybe?

Look, I get it: When a critical piece of environmental control equipment fails (like a heater), especially during a cold spell or heatwave, it could be life or death for your fishes. If you're about to spawn a particularly picky fish or rear some fry, it could be a serious problem. You can't really downplay those concerns.

However, some of the less dramatic, non-life-threatening issues, such as, oh- a light staying on or off longer than usual one evening, a circulation pump stopping unexpectedly for a couple of hours, or forgetting to change the carbon in the filter one week, don't really create that much of a problem for your fishes when you really think about it objectively, do they?


At some time during the existence of our fishes in the wild, there was a temporary blockage in the igarape in which they resided, slowing down the normal flow of water. At some point, there might have been a once-in-a-century cold morning in the tropics, right? At some point, perhaps the swarms of Daphnia or Cadis Fly larvae that were so abundant for months at a time, just weren't...

In most instances, the reality is that the animals that we keep are not so delicate, and the closed environments we provide aren't running so "close to the edge" that we should panic when some random factor changes things up one day.

Again, what I mentioned already bears repeating: When we purchase our fishes, they are unceremoniously netted out of the tank (or stream, lake, river, etc.) environment in which they reside, placed in a plastic bag, transported for who knows how long, and possibly making a few stops on the way before ultimately landing in our aquarium. 

That's a LOT of changes to cope with. Stress.

But guess what? Fishes manage to deal with it. Somehow. 

Sure, our first choice is to have rock-solid parameters and environmental conditions for our fishes 24/7/365, but sometimes stuff happens that throws a proverbial "wrench" into our plans. We have to be adaptable, flexible...just like our fishes apparently are.

So next time your light doesn't come on, or you forget to feed your fishes as you rush off to work some morning, don't stress out over it. They'll be fine. Keep calm. Always keep your concern high, find out what might have went wrong, but don't let obsessing over your fishes keep you from focusing on the even more important things in life (yeah, there are a few, right?).

And remember, sometimes unexpected things DO happen in the Amazon. Sometimes, we don't have the answers for everything. Sometimes we don't have to overthink this stuff. And sometimes, the unexpected can trigger some beneficial- even amazing- consequences. And sometimes, taking a sort of "hands-off" approach is actually the way to go.

There's so much to learn in this much to think about...and too many opportunities to overthink stuff.

It's almost impossible to eliminate any probability of failure in our aquariums, especially when we are dealing with variables like living creatures, dynamic chemical environments, and complex system designs. Even the most simple, "low concept" aquatic display has literally dozens of potential "failure points"- each which could cause consequences ranging from annoying to tragic, depending upon how they manifest themselves.

We just need to learn to relax, look at the realities of what's actually happening in. our tanks, and adjust IF needed.

Stay flexible. Stay brave. Stay curious. Stay thoughtful. Stay calm...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


April 29, 2022


Fresh and new.

I was chatting with someone on Instagram the other day, and he brought up the idea of trying to do a new tank based on____________.  NOT based upon some idea he had in his head. NOT based on a wild habitat which he saw. NOT even based on a plant or a fish or a rock that he wanted to work around...Nope. He wanted to do the same thing as some other guy, and to be able to garner all of the cool "accolades" which accompany a tank going "viral" or whatever.

Oh, and it HAD to be "amazing." (his words)

I was like, "Dude- do what you want...but the emphasis should be on the 'what YOU want' part.  Not what people on social media would find 'cool!' Don't fall into that trap..."

My usual schtick. Yeah.

I was simply dumbfounded that creating a near duplicate of someone else's tank he saw on social, for the expressed purpose of getting more attention on social was the entire "goal" for this tank build. And, that he was putting all this pressure on himself to "match" or "exceed" the that work he was essentially copying. Like, WTF?

Of course, it wouldn't be productive or even fair for me to simply trash the guy, I needed to help him understand how he was doing this to himself. On one hand, if you're trying to endear yourself to the "Every tank that looks like_______ is awesome!" crowd, this was a perfect recipe, I guess. On the other hand, when I pushed back, he did kind of sheepishly admit that this was a bit silly...and that he was a bit "burnt out" on what he was up to in the hobby at the moment.

Ahah..."Burnt out."

Heard that one before.

Of course, then the conversation briefly turned to ways to overcome this "burnout" that he and others sometimes fee within the hobby. While it's always possible to get "burnt out" even on stuff you love, I think that it's exacerbated by doing work which doesn't truly speak to you. Doing it for the wrong reasons. Or getting way over your head for something which isn't really what you want to do.

I guess "burnt out" is the wrong descriptor...More like, "benignly disinterested." It can be doing stuff that's actually interesting to you! Yup. Besides just doing stuff that speaks to you, I think the other key is to do a diversity of things which interest you at one time, when possible; to explore multiple "disciplines" within the hobby. Do more. Do different. Scratch the itch...

I love the idea of keeping a few different types of aquariums at any given time, if it's possible. I mean, it's a privilege to just be able to keep one aquarium. However, when you have the means and ability to keep a few tanks, not only does the real magic start happening, you have multiple avenues to direct your passions and energies. I like to keep tanks from different "disciplines"; in my case, blackwater/botanical, "evolved" brackish, and a coral tank.

There are real advantages to having tanks from various hobby sectors in play. First and foremost, if you should ever find get just a bit less stoked about one particular tank (or type of tank, in my case), you can focus on the one that speaks to you at the moment. Tweak the others when you feel more interested in them. It keeps you alive.

Keeps things fresh.

Staying fresh is quite important. The hobby is supposed to be fun, and I suspect that, for an increasing number of people, it's becoming more of a "chore" than anything else. This wasn't the first conversation I've had with a hobbyist who was feeling what this guy was feeling: A source of  self-inflicted pressure to do stuff...To "produce." 

And yeah, I DO think that this "pressure" is a direct "by-product" of social media. A human desire to be "accepted" as part of the "cool kids." And I think that's resulted in a lot of hobbyists getting a bit off course, and doing and sharing (or feeling compelled to) stuff that really doesn't resonate within them. I'll tell you one thing, this "pressure" has resulted in a large number of awfully similar tanks popping up on the 'gram and elsewhere...

I've commented about this before, but my Instagram feed is becoming a shockingly bland and replicative place. A see of sameness. I see literally dozens and dozens of aquariums done up in the same rigid "style", with the main differentiator being either how many sexy potted plants are on the shelves surrounding the tank, or perhaps a slight variation of the way the wood breaks the water line, or how many "Hakkai stones", "Frodo stones", or whatever the trending "rock du jour" is comprising the hardscape.

If I see one more breathless, "What fish do you think should we put in this new 'mini Rotala' tank!?" pseudo-tease post (when the reality is that they were always going to put in Rice Fish, Ruby Tetras, or White Clouds regardless.Who the fuck sets up a tank with no clue at all what they want to put in it? C'mon...), I'm going to vomit. And don't get me started on the copycat sterile-clean, ridiculously over-diverse, almost artificially "Nature Style" marine macroalage tanks which are starting to become the latest aspirational wet dream of every uninspired hobbyist looking to increase his following count and tag potential "sponsors" in his posts. 

Whatever happened for doing what resonates with YOU? 

I want to metaphorically beat the lameness out of you. Of course, maybe you really DO enjoy exactly copying someone else's tank. It's what you like.


I mean, look, if the "macro algae clean room fantasy masturbation tank" is your thing, do it. If you really love "ADA Black Root" and "Old Mountain Stones" or whatever, and they make your heart sing, use them. Don't let me shame you away from doing what you truly want to do. Where I WILL nudge you is when you want to do it for some crazy-ass reasons, like we just discussed. That's just not healthy. 

Doing something just to stand out from the crowd is a weird goal, too. But doing what you like- even if it just happens to be a bit different from the prevailing trends, truly stands out. For the right reasons.

What tanks actually DO really stand out to me hese days?

Well, it's not necessarily ones that use different materials or whatever. It's the ones that reflect a different approach. A story. Something which doesn't feel like it's trying to go over the top and out-create the (obvious) original inspiration, or match up to some hashtag-friendly trend, "just because." Something which feels authentic, because it comes from the heart of the creator, not from the Instagram feed of some aquascaping content aggregator.

The ones which truly stand out are standing out for a reason: Because they're unique, fresh, different. They reflect the interest and aspirations of their creators. They don't try to be "something", other than what they are. They don't need a fucking stupid name ("Heavenly Dawn ON the Hill of Light" or whatever) to "classify" them or give them "legitimacy."


Screw trying to get "picked up" by the aquascaping content aggregators on social media networks. Screw trying to get "likes" and 💕 and all of that shit. Just do something that you like and share it to inspire others to share their own unique work. Not another copy of yours. 

And there is another, sure-fire "trick" that can help you be happier in your own lane as an aquarist...

Think like a beginner.

Yeah. Really.

Beginners have this "thing..."

Perhaps the beginner knows something we don't.

I think I- we- that is, more "advanced" hobbyists...know too much. 


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

I think that so many hobbyists at our level of experience tend to overthink every aspect of the aquarium hobby. We carry "baggage." We worry about what the crowd on Facebook or Instagram thinks. It's quite evident- particularly during the new tank startup phase...Almost no one shares the earliest, dirtiest days of their new tanks. We feel the need to "prep" it for the masses. We don't feel it. Rather than just letting ourselves enjoy the moment- the wonder, and the awe that comes from doing something special, beautiful, and, let's face it- incredibly cool- we worry about shit like "presentation."

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

Shit, that IS something amazing, huh? 

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

We should know that. We know a lot of other stuff, so...

Perhaps- just maybe...we know too much.


We understand all of this stuff that's going on in our tanks. Yet, for some reason, many are afraid if it's a bit different than, or doesn't meet someone else's expectations. We worry about "them", because they might not approve...

Fuck "them."


We, of course, worry about our dream tank not being in the perfect state of awesomeness at all times, ready to show on Instagram Live, or whatever....

We stress about algae or cloudy water, or whatever.

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

I mean, when just having a glass or acrylic box of freshwater or saltwater filled with fishes in your home is a novelty- a cause for rejoicing, that's the magic part. As a beginner, 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, to most experienced hobbyists, some of this stuff can really suck, and is a source of shame for some reason.


And that is actually a beautiful thing- because, unburdened from this junk, 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- oh shit- the occasional out-of-place piece of wood in their aquascape. Shit, they likely don't really care what KIND of wood it is, either. They're not worried about that, or any other of a dozen minutiae like we are, because they don't KNOW that it's a "problem." 

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 shit by the thought of Glowlight Tetras, Amano Shrimp, Glass Catfish, and "ultra-common" Bettas taking up residence in the new little utopian microhabitat they just set up in their New York City apartment.

What about us- the so-called "advanced" or experienced hobbyists? Can we liberate ourselves from this hell of our own creation?


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 decisions based on what our research- gut, or yeah- I suppose, experience- tells us is the "right" thing to do, then letting stuff happen, and accepting it.

Not to waste any energy worrying about how many damn "likes" our next tank pic gets.

In other words, taking control of the influence of others, as well as that our own experience, rather than allowing it to taint our whole journey with doubt, dogma, second-guessing, and over-analysis of every single aspect. Don't get high on the accolades, or pissed off about the criticisms which others may levy. 

And relaxing into it. Enjoying engaging in the hobby for YOU.

Embracing the sheer joy of being a beginner. Again. it's exciting. It's fresh. It's healthy. Even if you're doing more "advanced" stuff...

Let go. Don't do stuff in the hobby to please others...that's a recipe for misery, trust me.

Do stuff that's fresh, new, and yours.

Stay creative. Stay resourceful. Stay inspired. Stay original. Stay bold...

And Stay Wet.


Scott Fellman

Tannin Aquatics 



April 25, 2022


The crowd? Or just the community?


One of the great things about being in the aquarium hobby for a lifetime is that you have numerous opportunities to learn things, acquire new skills, sharpen old ones, and to occasionally re-think stuff you thought was not even questionable in the past.


For example, stocking our tanks.

When it comes to stocking aquariums, I've historically been extremely conservative, erring on the side of under-stocking, and simply leaving a a lot more room for additional fishes in most of my systems over the years. I would often be teased by friends about how "empty" my tanks looked, lol.

I think that part of this conservative trend comes from my aquarium upbringing. My dad bred fancy guppies, and was himself brought up following the teachings of the legendary masters of the guppy hobby, like Hahnel, Sternke, and Alger, who advocated moderate stocking of their guppy tanks, for a lot of good reasons.

I grew up reading all about them as a kid in my dad's old aquarium books, and applied their ideas to my work, too.

Some of my attitude towards stocking was based upon the technology I grew up with in my earliest days in the hobby. Inside corner filters, outside power filters, and under gravel filters were thought to have a rather limited "capacity"...for what, I'm not exactly certain, but nonetheless, I followed the "rules of the day" when it came to common sense stocking.

Of course, when I was a teen, we had the dawn of the modern reef aquarium hobby, and its evolved practices and technology, which I have since spent decades playing with. The advent of trickle ("wet/dry") filters, evolved protein skimmers, and the practices of utilizing live rock and sand in reef tanks changed the game. A marriage of biology and technology as never before. It kept evolving to this day with sumps, calcium reactors, dosing systems, LED lighting, and now, with automatic filter rollers.


Suddenly, not only could you keep delicate organisms like stony corals alive, you could keep more of them, because of the practice of building up an ecosystem- a "biological infrastructure", if you will- which included a heavy reliance on beneficial bacterial populations and managing the specific physiological needs of these organisms.

I was still a bit conservative in stocking for quite a few years; typically massively over-building nutrient export mechanisms and practices into my systems. They definitely served me well, even though, looking back, I think I was traversing deeply into "overkill" territory!  It wasn't until quite recently that I really began to question why I was so conservative, and for what reasons. "Cleanliness" (for want of a better word) was, for many years, seen as the way to get great results.

The reality of this over-simplified mindset on near-sterility eventually made me realize I was wrong. When I was a partner in a coral propagation facility, early on it became increasingly obvious that the desire to literally polish the shit out of the water had the opposite effect on the corals. We were simply making the water too "clean!" Only when we allowed some nutrients to accumulate, and relied more on natural processes than "technology overdrive" did our corals start to really thrive and grow faster.

And, this definitely had an impact on my freshwater practices.

In 2015, when we started Tannin Aquatics, we pushed heavily on the idea of using botanical materials to help create a functional biome- an ecosystem- to facilitate nutrient processing and supplemental nutritional resources for our fishes and other organisms that reside in our tanks. I spent a lot of time studying and researching the wild aquatic habitats which enthralled me. Married with a more "holistic" approach, which views the aquarium itself as a "filter" of sorts, my conservative approach to stocking began to evolve and liberalize considerably!

So here we are today, with me talking about a totally different mindset on stocking your botanical-method aquariums. I needed to provide you with that brief history of my hobby experience on the topic to provide some context, and to reassure you that I'm not just some asshole telling you to "stick it to the man" and blow off a century of aquarium hobby "best practices" just..."because!"

Now, before I get into the meat of today's topic, let me clarify a few things. I am NOT calling bullshit on the idea of common sense in aquarium management. I am NOT advocating that everyone fill their10-gallon starter tank with 50 Neon Tetras, or other equally stupid things. 

I am still a firm believer in NOT over-stocking your tank.

I just think that the "limits" are farther out than we have previously assumed. Yeah, I wonder, what exactly is the definition of "over-stocking" anyways? Is it a sort of subjective thing?  Or, some hard-and-fast "number?" Is it a tank that simply looks ridiculously full of fishes? Or is it a "thing" that is determined by water quality (ie; nitrite, ammonia, nitrate, phosphate, etc.) or other environmental factors which are measurable (pH, conductivity/ORP, dissolved oxygen levels, etc.)?

Likely, the latter.

I don't profess to have the authoritative answer to every aspect on this topic. I can only share what works for me; where I've come from, how I reached this point, and what it has done for the fishes which I keep. Again, there is likely as much subjectivity as there are obvious answers to stocking methodology.

I mean, on a superficial level, there is not a lot of difficulty in calling bullshit on the idea of stocking a full-grown Clown Knifefish, a large Pleco, and an adult Oscar in a 20-gallon aquarium, right? The physicals pace and physiological ability of the tank to support that much life is obvious. The amount of metabolic wastes they produce would literally overwhelm virtually any practical filter or biological processing system which you could attach to such a tiny tank, in hours. And not to mention, it's simply cruel to keep these fishes in a tiny space like that..sort of like having to spend the rest of your life in a closet with 3 adult strangers!

This kind of overstocking should be obvious to all.

And I'm not talking about trying to stuff 80 Mbuna in a 50 gallon tank, or whatever. Fishes which have significant space needs because of their territorial behaviors or "pecking orders" typically don't play well with this concept. I've heard the theory that the "overcrowding" lessens aggression or whatever... I disagree, as substituting once stress for another is not a good thing.

What I'm talking about specifically here is figuring out how many small (and by "small", I mean fishes that are 1"-1.75" or so in length, like characins, Rasbora, etc.) can be kept healthily, humanely and safely in that same 20-gallon aquarium. 

Consider fishes like characins. Okay, the small ones, like Hyphessobrycon, Hemmigrammus, etc. Not fucking Pacu or Piraniah, etc. 🤬

How much metabolic waste does a fish that weighs a gram or so actually eliminate into the aquarium on a daily basis? I'm sure there is a study of that...somewhere. I'll bet that if we knew the actual numbers, a lot of minds would change on stocking. 

Of course, there are also the most banal of considerations when talking about more densely stocking your, aesthetics. I mean, do 50-100 fishes of ANY type and size look good in ANY type of aquarium to you? Do you actually WANT that many? Or, can you afford that many? I mean, 100 Tucano Tetras, for example, can set you back a serious amount of cash!

But yeah, lets stay on the general topic of characins....

Many of these little characins occur in large shoals or schools in Nature. That's how they live. They've evolved to live that way. They feed together, shelter together, and spawn together. As a community group. They are often gregarious and social, and display their most natural and healthy behaviors when kept in such groups. They feel safer that way. These little fishes are almost like a single, communal organism!

They will generally simply fail to thrive, or at least, be at their best- when not kept with a significant number of their own kind in an aquarium setting. There is a legitimate reason why keeping 1 or 2 Cardinal Tetras in a so-called "community tank" is just not good. You're often told to keep "at least 6-10 specimens or more together" for them to be at their best.  

It's the "or more" part that intrigues me, of course. It's logical. There is a reason for that, as we just discussed.

They live in large groups in Nature. Fact.

I mean, yeah, you're limited by the size of your tank, 'cause it's not the Igarape Dracua in Brazil or wherever. It has no large water "flow through", or a vast supporting terrestrial ecology. It has different external environmental inputs, and a finite amount of water. So your job as an aquarist is to find that "sweet spot"  which provides your fishes the ability to live their lives in social and physical comfort, while maintaining acceptable water quality. That means keeping them with a significant enough population of their peers to meet their needs, while keeping water quality and health at optimum levels.

I actually see this challenge as a call to simply add more fishes to our tanks, when permissible, and to create environmental conditions appropriate for them to thrive.

The two need NOT be mutually exclusive.


Now, look, once again, this is not a call to run off, like the proverbial "headless chicken" to the LFS and buy 300 Cardinal Tetras for your 50-gallon tank. That's just dumb. It IS a call to consider if that 50-gallon tank can be created and managed in such a way as to responsibly provide a healthy, sustainable home for say, 50-75 of those same Cardinal Tetras. 

I think that it can be. And this is not one of those things that I'm pushing out to be "in your face"; to garner those comments like, "Sure you CAN, but why WOULD you?"

It's not like those, "I do THIS and never do water exchanges!" kinds of asshole-like ideas which provoke nasty discussions on forums and Facebook groups. I'm not advocating some sort of "workaround" to best Nature here. I'm advocating looking at what occurs in Nature and figuring out if we can replicate some aspects of it in the aquarium, for our fishes benefit.

It's about creating conditions to maintain appropriately-sized populations in our aquariums. Now, sure, there are studies out there of wild aquatic habitats and their fish population density and diversity, where transects of wild habitats have been conducted, which, if you do some algebraic calculations, could yield some approximate numbers of fishes of a given species per a given area. Again, as I just alluded to, there is more to it than just "X" fishes per square meter", or whatever-but it is a starting point, right?

I mean, if the fishes have so much room in Nature, why do they congregate together in such large numbers in a small area?

You need to take into account your ability to provide an aquarium environment and maintain husbandry practices which can facilitate more dense population of fishes. I don't take this responsibility lightly. You shouldn't, either.

I am an extremely careful feeder, believe in good oxygenation and I am a champion of significant nutrient export (ie; water exchanges and use of biological/chemical filtration media, etc.) in all of my tanks.

The idea of building up a substantial (okay, let's change the adjective to "significant") population of little characins was something I'd always wanted to do over the years. However, I spent way too much time buying into "conventional aquarium thinking" and limiting myself to "1-inch of fish per gallon", or whatever the prevailing "guidelines" were at the time, to even think about challenging that.

And then, over time, I sort of started thinking about the rationale we employ for limiting stocking in aquariums: To create environmental conditions conducive to fish health. I realized that there is more to it than just listing the numbers of fishes. I believe that  you can actually have way more than the "one inch of fish per gallon" thing and still provide optimum environmental conditions...if you understand what those are for your fishes, and make achieving them part of your whole system from day one, and husbandry routine thereafter.

So, as I built up my population of 70 small characins in a 50-gallon tank, it occurred to me that it works because I do the things necessary to make it work. You can't have a large population of fishes in a given tank size without proper circulation, filtration, a water exchange regimen, and careful feeding. Give-and-take. Like everything in this hobby. You can't "have it all." But you CAN have most of it! If you're flexible and willing to compromise.

I firmly believe that a botanical method aquarium, with its significant and well-thought-out emphasis on ecology, is the perfect starting point for a densely populated tank. As I've shared with you often, my thinking has long been that you should actually consider the tank itself (or more properly, the botanical environment within it) as the"biological filter", and simply use aeration/surface skimming and/or circulation pumps to facilitate the gas exchange.

After almost 25 years of playing with this botanical stuff, I'm convinced that the microbiome provided by a properly set up and managed botanical method aquarium provides a huge amount of biological support for the fish population. Not exactly revolutionary, of course- but an idea that's often overlooked today.

Think about this:

The botanical materials present in our systems provide enormous surface area upon which beneficial bacterial biofilms and fungal growths can colonize. In addition to physically fragmenting botanical materials, these life forms, collectively referred to as "epiphytes", utilize the organic compounds present in the water as a nutritional source. They also provide supplementary/primary food sources for a huge array of organisms within the aquarium itself, including the fishes.

Just like what happens in Nature.

In the case of our fave aquatic habitats, like tropical streams, ponds, and inundated forests, epiphytes are abundant, and many fishes will spend large amounts of time foraging the "biocover" on tree trunks, branches, leaves, and other botanical materials.

The biocover, as I just mentioned, consists of stuff like algae, biofilms, and fungi. Nature's "filters." Although most fishes use leaves and tree branches for shelter and not directly as a food item, grazing on this epiphytic growth which occurs on them is very important. You're unikely to have fishes in an aquarium decimate all of this growth, so a sort of "balance" is achieved.

Yeah, as I've said a million times here, I am of the opinion that a botanical-method aquarium, complete with its compliment of decomposing leaves and seed pods, can serve as a sort of "buffet" for many fishes- even those who's primary food sources are known to be things like insects and worms and such. Detritus and the organisms within it can provide an excellent supplemental food source for our fishes!

These organisms also provide a sort of "onboard nutrient processing" service for the aquarium in which they reside. A "filter", if you will...but one with a "feature set" and capacity far in excess of most commercial filter systems you can buy. It's free, and super reliable.

You just need to give it what it needs in order for it to work.

So, like, your filter is almost "supplemental" in this role, really. Think about it:  In most filters, you're trying to recruit bacteria and other microorganisms to help process metabolic wastes from your fishes. Well, as we just alluded to above, the biome within the aquarium itself does the bulk of that work, really.

The type of filtration, or more important, the quantity of filtration, and the way in which water is returned- together play a huge role in supporting a significant fish population on a long-term-sustainable basis. No real magic here. Nothing new..except a different understanding of the role that the "filter" plays in the aquarium.

Your aquarium should have some water movement, to facilitate gas exchange, provide a little "exercise" for your fishes (that sounded stupidly quaint, but you get the picture), and to avoid the formation of thermal, pH and/or nutrient layers in our tanks.

Gas exchange (the process in which carbon dioxide exits into the atmosphere and new oxygen from the atmosphere is dissolved into the water) is really important in aquariums, and aeration from filter returns helps facilitate the process. Fish need oxygen (like 5-6 parts per million) in their water. Now, it's not mandatory to have airstones, filter returns, or surface skimmers to create surface agitation, but it sure helps, particularly if you keep a large population of active fishes! 

I suppose you could say that the "purpose" of aeration is to "break up" the surface of your water. You’re not going to separate the oxygen molecules from the water and force a gas exchange within the water column, by cranking up an ayirstone- that's not what it does. But it will help break up the surface boundary layer to facilitate gas exchange. I guess that's why I love surface skimmers, or filters which skim the surface boundary layer. They just make the gas exchange process easier and more efficient.

And of course, simply choosing an aquarium with a large surface area is important and beneficial, too. Wider, more shallow tanks are always better than tall narrow ones at this.

What about foods- and the way we feed our fishes? 

Feeding is, of course, very important. As is the type of food, the frequency, and the amount dispensed.

As a long-time proponent of primarily feeding frozen foods to my fishes, I realized that frozen is not the panacea that it seems to be. Sure, there are certain benefits to being able to feed fresh stuff like brine shrimp and worms and things in a convenient fashion. However, frozen foods also often have a significant amount of organic material- stuff you may not want in your tank- with the food as a part of the process of manufacturing them.

The "juices" contained in them, which, when added to the aquairum water can lead to accumulations of nitrate and phosphate- the "enemies of high water quality"- within the aquarium if you're not especially fastidious. It's easy to literally "kill your fishes with kindness!"

I think that, if you're trying to push the fish population a little, careful, non wasteful feeding becomes really important. This would necessitate a change to other foods- like pellets. Yeah, I admit, I used to hate pellet foods. I thought they were sort of nutritionally-defficient "kibble" for fishes. And most of them were- back in the day!!

Fast-forward to now...There are some amazing, super high-quality, highly nutritious pellet foods out there which are easy to feed, contain almost no fillers or non-nutritious ingredients, and which are easily digested, encourage more uptake of nutrients and less metabolic waste, and can be fed in such a way as to assure that less goes "down the drain" as opposed to in your fishes' mouths.

Can you still use frozen food in a more densely-populated tank? Of course! I do! Just be more careful. Don't feed it every single day, multiple times a day, in large amounts.

Little compromises. Changes in the way we do stuff. We know how to work with that.

And one other thing...You won't just dump the entire population of your fish into the aquarium from day one, right? I mean, you shouldn't. At least, not without some preparation. You need to allow the resident beneficial bacterial/microbial population to build up to handle the increase in metabolic wastes produced by the fish population.  Slow advance of adding the fishes.

Okay, building up a population of beneficial bacteria to tackle the metabolic waste products produced by your fishes is decidedly conventional  aquarium hobby thinking. And there ARE some (oh, shit...) "hacks" that, in theory and practice, could make it possible to add a LOT of fishes from the "get go". Intrigued? Well, you know the "hack" I'm gonna talk about. It's called, "pre-stocking." It's pretty straightforward, but it requires time. And patience! (shocker, I know. Only my "hacks" would not really be "hacks". Or not "time-saving" ones, at least...)

Here's the deal:

Set up a botanical method aquarium with a large number of leaves and other botanical materials and substrate from day one. Inoculate with live bacterial cultures (PNSB and/or Nitrobacter/Nitrosomanas). Throw in a bit of fish food if you want. Stock with organisms like Daphnia, Cyclops, Paramecium, etc. Let the tank "run in" for several weeks, or a month or more if you can handle it (you can). This will give the microbiome and overall ecosystem a chance to literally arise and "assemble itself" before the fishes are added!

Then you could add most, if not all of the fishes at once. Seriously. 

Is there a risk to this? Well, sure. Working with live animals in a closed aquarium always involves some risks. No guarantees. You could still lose fishes. And you still need to monitor nitrite and ammonia, and to understand the concept of the nitrogen cycle. You need to be aware and do a little work. I've done this exact thing literally several dozen times in the past 20 or so years, including just a few weeks back, BTW) and have never, ever had either detectible ammonia or nitrite, let alone a "cycle" after adding the fishes. Other than a few "jumpers", I've seldom lost a fish to this process.

Yeah. I'm no fucking visionary. And I'm not the only hobbyist who's done this. Plenty of botanical method aquarium enthusiasts employ this  same practice with similar tremendous success. I mean, it shouldn't be a real surprise, because it's not really a "shortcut."  It's not some "miracle." It takes time!  That's the compromise you have to make. You're simply establishing the ecology and the nitrogen cycle within the tank before the fishes arrive. "Fishless cycling" as the process is known, but with a botanical-method twist and it's associated benefits!

This is also nice because it slows you down ahead of adding the fishes, and gives you time to acclimate and quarantine all of your fishes before releasing them into the display aquarium. It also has the advantage of starting your fishes in an aquarium which is, by many hobby definitions, very well "established" before they're ever added! Other than the "adding most of the fishes at once" part, it's actually not all that different from gradually stocking a tank over  time, except that a more robust ecology was in place and operating long before the fishes arrived.

And of course, you could employ the same mindset, yet gradually build up a fish population anyways- perhaps for other reasons- like getting the more timid fishes settled in first, before the active, crazy ones, etc. Apply it in a manner that works for your situation.

And of course, perform regular water exchanges on your aquarium. Make them a ritual. Regardless of how comprehensive the ecology in your tank is, it's not an open, natural habitat.  It requires proper care. If you're going to ply new territory, don't abandon all of the tools that got you there in the first place. You're smarter than that. I know that you are!

So yeah, THAT is how I have 70 healthy, happy, and active little fishes in my 50-gallon aquarium. I didn't "cheat." I didn't create some dependency on a huge and absurdly complex commercial filter system, or some magic elixir. I'm not slave to massive water exchanges daily. All I did was think about how ecology works in aquatic systems, partner up with Nature, deploy all of the things we've talked about in our botanical method aquarium work for years now, and provide the optimum conditions to allow a (dense) population of fishes to thrive from day one in my tanks.

I compromised when required, and understood many of the nuances involved in keeping large groups of fishes. I studied what occurs I the wild and figured out how to make it work in my aquariums.

You can, too.

It's literally another mental shift. An example of looking at things from (as we say here) a slightly different perspective...

Again, some of you may disagree with this approach vehemently. Some of you may be like, "WTF, Fellman. Freaking irresponsible." Some of you might shrug and say, "Okay, yeah. Whatever. So?" A certain percentage of you might have already thought like this. A smaller percentage may just give the approach a try in the future.

I encourage you to do what you think is best for your fishes.

Regardless of how you stock your tanks, study some of the science behind it. Understand the nitrogen cycle, and the importance of building up an ecology in your aquarium. Shift to considering the entire aquarium a miniature ecosystem, capable of supporting a vast array of life at many levels. Study the needs of your fishes, and figure out the best way to meet them.

Don't take shortcuts for the sake of "gaming the system" (ie; Nature). The "system" will simply kick your ass (and kill your fishes in the process). Don't just take my words as "gospel" here, nor the guy with 40,000 followers on YouTube, the Instagram "influencer", or your cousin Brian.  

Think it through for yourself. 

Responsibly experiment.  That's really the only way to advance this hobby. 

Sorry, Brian.😆

Stay curious, Stay bold. Stay thoughtful. Stay experimental. Stay logical. Stay grounded...

And Stay Wet.


Scott Fellman

Tannin Aquatics 




April 21, 2022


Finding your own lane: The real "Mental Shift!"


Okay, I"m going to use the phrase, "mental shift" for like the 30,000 time here in the last 7 years, but I think that it's pretty important. 

I've seen several friends and fellow hobbyists "find their lane" in the aquarium hobby lately, and it's been truly remarkable to see. Watching others be delighted by things which they might have never even considered, and then seeing how they resonate, is an amazing thing. Truly inspiring.

I was looking at my latest botanical method aquarium the other day, and literally admiring the fungal growth and biofilms emerging from the wood, and lightly coating som of the leaves on the surface of the sedimented substrate. I was savoring the tinted water with a slight "haze", likely the result of a combination of super fine constituents from the substrate, and some organics from the wood and leaves.

And I though to myself, "Damn, this one is looking perfect!"

How far I've come, to the point where what many consider absolutely horrifying and aesthetically nightmarish, is to me, an amazing expression of Nature at it's most authentic. Like, I remember setting in the wood and such in the first days of this tank and being sort of repulsed by how harsh and sterile it felt before the wood was colonized and the water began to tint up and go slightly turbid. It felt...I dunno- a bit "unnatural."

Minutes later, as I was scrolling through what I could only characterize as the bland "sameness" of all of the perfectly manicured, spotlessly sterile-looking "Nature Aquariums" which seem to populate my Instagram feed, I once again had that realization about just how far I'd come as a hobbyist, in terms of what I find compelling, interesting, and attractive. 

To me, there is sheer joy in seeing the things which arise in wild aquatic habitats (biofilms, fungal growths, decomposition, etc.) occurring in my tanks. It's like a little victory when Nature makes Her appearance! I find myself watching videos or glancing at images of the wild aquatic habitats which inspire me, and feeling this incredible sense of satisfaction at the parallels I've experienced- at the "blurring of the lines" between Nature and aquarium that I helped foster.

Now, that's not to say that I don't enjoy looking at the work of the many talented aquascapers out there who specializing in the artistic, highly conceptual stye. I appreciate a beautifully done planted aquarium, Iwagumi, or rocky hardscape as much as anyone. Hell, I've gone so far as to state that if one of my "superstar" aquascaping friends pops into Los Angeles for a few days, and wants to set up one of these tanks up for me in my home, I wouldn't complain!

I just have no desire to do one myself. None whatsoever.

I've found my lane. 

I know what speaks to me; what I enjoy, and why.

That's really powerful. It feels great.

After a lifetime in the aquarium hobby, I've found  the things which I like, and practice them without concern about what anyone thinks, or how I will be judged, or the type of armchair analysis that my aquariums will be subject to. To put it in rather simple, direct terms, I simply couldn't care less what others think of my work. I do it for me. Oh, and to push the limits of the botanical method. And if it inspires other hobbyists to do similar things, that's a huge win.

This is a very healthy attitude for everyone to embrace. I barely hear the accolades we receive for this stuff, and completely disregard any negative comments. Tell me that what we do is "stupid", and "ugly", and "sloppy." (All "criticisms" which I've heard over the years...) I just don't care. I cannot stress this enough. I will, however, push back when someone makes a comment which incorrectly implies that what we do is messy or reckless or dangerous or whatever, because it's just plain wrong. We don't want people perpetuating incorrect information about this stuff.

Those kind of "criticisms" from those who have limited knowledge of a subject, yet feel compelled to shit on others, have for years thwarted hobbyists from trying things outside of the "generally accepted norms", and it's time for that nonsense to stop. Perpetuating myths about various hobby topics which the "critic" has no firsthand experience with hurts everyone. Regurgitation of misinformation is damaging. I see those negative comments as opportunities to educate people about what we do, and why it is incredible...

We all should.

In today's "Insta-famous" world of viral videos and over-the-top ideas, where everyone fancies themselves an "influencer", it's nice to feel that sense of comfort that you get when you know that you're doing exactly what you love the most. I hope that every hobbyist can feel this! It's satisfying, liberating, and incredibly enjoyable.

It's healthy.

Besides, if everyone is an "influencer", who's actually doing stuff? 

I get a lot of questions from hobbyists of all ages who are intimidated or concerned by "them" or "they" on social media. Worried about how their work will be received and analyzed. Hobbyists who are held back because they feel that the comments and criticisms of others are going to somehow "ruin" them.

That's unhealthy.

Realize that, when you're doing exactly what you want- what you love- that none of this stuff matters. Criticisms will keep coming...

I experienced this a lot in the early days of Tannin Aquatics. A number of people literally told me that the idea of utilizing all of this botanical material to replicate habitats like the igapo and varzea and such in closed systems would lead to polluted tanks, wildly fluctuating environmental parameters, and fish death.

Having created numerous systems based on the concept over the years, I pressed on- stubbornly. Because I knew that there was merit and benefit to what I was doing. And, thanks to all of you- the brave hobbyists who also shared our vision- we've seen a worldwide renaissance in the idea of utilizing botanical materials to create functional habitats in our aquariums.

It would have been so easy to just fade away if I listened to the negativity.

But, hey- this is not about me and how cool I am. That was just a personal example of this phenomenon!

I've written about this "negativity" stuff before over the years, and still talk about it in in my lectures, because it's an issue that doesn't always seem to go away.

Why? What causes people to criticize and discourage others so strongly in this hobby? It's kind of weird...

It's like there are some people who simply feel compelled to sabotage the well-intentioned, yet progressive efforts of others. It's like they're afraid to see others succeed or change what's become comfortable for them. I imagine this is what people felt when they first introduced TV and people didn't want to give up their radios, or whatever.

Yeah, I can't help wonder if it's fear. Really.

Fear of change. Fear of not being "the expert" on something. I'm not sure. But it's a thing we have seen many times in the hobby. It's usually just a few loud people, but they can do surprisingly large amounts of damage thanks to the utility of the internet and the power and reach of social media.

So, what's the "antidote" to this nonsense? 

Just don't listen to the noise.

And for those of you who are pioneering new ideas?

Look, there is always someone who has to be the first to accomplish something great and new and different. Someone who can overlook the negativity and "smack talk", to fly in the face of convention while taking that road less traveled. Someone who has to shake off the "taboo" fears created by others. To move forward, despite the "criticisms."

This is how we progress. This is how we will continue to progress in the hobby.

And more important, this is how we inspire a new generation of hobbyists to follow our lead, for the benefit of both the hobby and the animals that we enjoy. Nor can we dispense advice to fellow hobbyists with a dogmatic attitude that discourages progress and responsible experimentation. It will simply stagnate the progress of the hobby we all love.

Just be you. Be cool. be authentic and honest. 

I’m not advocating the abandonment of common sense and healthy skepticism. Everyone should not make a mad dash to the LFS to assemble schools of Black Diamond Stingrays.

What I AM pushing is that we (and by “we”, I mean every one of us in the hobby) should encourage fellow hobbyists who want to experiment and question conventional wisdom to follow their dreams. If someone has an idea- a theory, and some good basic hobby experience, there is certainly nothing wrong with that. Yes, there is the sad fact that some animals might be lost in the process. It sucks. It’s hard to reconcile that…and harder to stand by it when animals are dying.

However, that may be the cost of progress.

The cost of not progressing might be far higher: The loss of countless species in the wild whose habitats are being destroyed, while those of us with some skills, dreams, ideas, and respect for the fishes sit by idly -watching them perish, failing to even attempt captive husbandry and propagation for fear of criticism and failure from the masses.

There has been very real talk over the years about making the importation, and possibly the distribution- of live corals and some fishes illegal in many nations. It's not that unrealistic a possibility. Who knows what opportunities might be missed if we fail to even persue our goals?

So, yeah. it's bigger than just not wanting to post pictures of our new tanks on Instagram or whatever. for fear of criticism. Not making the biggest mental shift of all- the one which enables you to find-and stay- in your own lane- creates a vacuum of progress and progression which can cause stagnation.

So, don't fear the criticisms. Don't worry about the naysayers. Don't fall for the negativity. Don't be discouraged. Ever.

Stay bold. Stay strong. Stay committed. Stay thoughtful. Stay creative. Stay in your own lane...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


April 19, 2022


The filter you use...The filter you have.

When it comes to keeping botanical-method aquariums, I realize that we spend a huge amount of time talking about mindset, mental shifts, preparation, ecology, etc., but scant little time talking about less exciting, more "nuts-and-bolts" stuff, like...filtration.

So let's tackle that today! Now, it's not the first time that we've covered this topic over the years here, but it comes up a lot, so it's worth discussing again.

First of all, what do we mean when we talk about "filtration?" To me, filtration can mean a mechanical, chemical, or biological means to remove unwanted "stuff" from the aquarium water. (Do you like that "stuff" part? VERY scientific, huh?😂)


In a botanical-method natural aquarium, filtration and its companion, water movement, are influential and pretty important in the grand scheme of things. As with any aquarium, it's important to apply filtration that keeps up with the specific needs of your tank and its inhabitants. Of course, with the heavily botanical-influenced aquarium, there is the added consideration of all of those leaves and pods and such.

Are they a "burden", though?

These items not only are part of the "hardscape"- their very nature makes them a component of the bioload of the system- and due consideration needs to be paid to their impact on the closed system's environment. Remember, leaves, seed pods, and the like are "ephemeral"in many respects, slowly decomposing and physically breaking down, releasing not only "bits and pieces", but dissolved organic materials as well. 

That's where filtration comes in.

Now, Nature provides "filtration" in the form of the nitrogen cycle and the bacteria which accompany it. Bacterial biofilms- the bane of many a new aquarist- are actually a true benefit because of what they are comprised of (bacteria, hello!), and for the potential supplemental food source they become...Oh, I"m meandering, yes. We'll get back to that. And of course, fungal growth on the botanicals also serves to physically break down and "process" some of the botanical materials and their accompanying organics.

Now, as fish geeks, we aren't just going to rely solely on bacteria and fungi to do the "heavy lifting" of filtration for our tanks...I mean, we could, in theory. However, in practice, we need some help. That's where "filters" come in. The first consideration is, of course, choosing a filter system of the appropriate size for the tank you're working with. That is kind of a "no brainer", since we typically all know how to do that (ahhh, I'm assuming)- and if we don't, we can easily research this topic on hundreds of sites all over the 'net. 

The other consideration is what you're trying to achieve with a filter system. Is your goal to remove bits of particulate matter from the water column? To chemically adsorb/absorb nutrients or unwanted compounds? Or, is it to facilitate the growth of beneficial bacteria and encourage biological assimilation of organics? Ohh, we'll come back to the last one later, okay?

Let's "cut to the chase" here:

At the end of the day, you can use pretty much ANY type of aquarium filter in your botanical-method aquarium: Cannister filters, inside filters, hang-on-the-back power filters, sponge filters, "matten filters", sump systems, all-in-one aquariums...Hell, even under gravel filters if you're old school! It really doesn't matter. They can all get the "job done"- assuming that the job is to accomplish one of the things I just mentioned.

I think that the "big issue" which forms the basis of a lot of the inquiries we receive from our community about this topic is what kind of filter media you need. This comes up a lot because many hobbyists relish the tinted water, and are rightfully concerned about whether or not popular chemical filtration media like carbon will remove the tint we all love.

Activated carbon.

Personally, I love the stuff, and rarely, if ever have ran an aquarium without it.

My bias towards using carbon in my aquariums comes from years of keeping reef aquariums, and later, co-owning a commercial coral importation/propagation facility, which had thousands and thousand of corals in tens of thousands of gallons of water.

Corals produce copious amounts of slime, mucous, and metabolic waste, not to mention "allopathic compounds" (ie; chemical "weaponry" used to defend their turf against intruders), and carbon, along with admittedly more efficient means, such as ozone and protein skimming, formed a sort of defensive "triad" to keep the animals healthy and water quality high.

Oh, and we also employed water exchanges, of course.

And yeah, we used a "shit ton" of the stuff in our facility! 

For reefers, the benefits of carbon use are really pretty apparent:

It reduces discolorations in the water.

It may bind some organic toxins.

It can be a place for beneficial bacteria to use as a "culture media."

It may remove copper and other trace metals (which bind to organic matter which, in turn binds to activated carbon for removal.

What about for us- the botanical-method aquarium crowd?

As we've discussed many times here, there is a sort of obsession those in our world have about keeping the water in our tanks dark and earthy-looking, and the idea of using chemical media with known adsorbent capability like carbon seems a bit "counter intuitive" to some. Carbon does excel at removal of compounds like phenols and tannins.

I'll often tell people that I use it more-or-less "full time" in my blackwater, botanical method displays, and this elicits the online equivalent of raised eyebrows now and again. "Tinters" will ask, incredulously, "Doesn't this stuff remove the color from the water?"

To which I respond, "Yes, it some extent."

Please DO look at some pics of my tanks, and tell me if I've been removing "too much" tint via my use of carbon!

Yes, carbon can remove some of the tint and probably even some of the valued humic substances and other beneficial compounds exuded by botanicals. It's not selective. That being said, it also can remove impurities, like volatile dissolved organic compounds, urea, some metals, etc. It's valuable stuff. The key is to just not overdo it.

(Activated carbon "pro tip":  Since It will remove the colors imparted by tannins, if you use the amounts most manufacturers recommend, just use less. Like 1/2 or 1/3 the recommended amount. Or, consider the use of other less "indiscriminate" chemical filtration media.

There are a lot of different chemical filtration media out there, and not all of them will remove the color imparted by tannins. "Now, the tough love" part?  I can't stay up on all of them, largely because I don't use them. It's not my job to direct you to the right one, okay? It's yours. Do your homework. You can do it!)

It should be noted that activated carbon does not remove all possible toxins or unwanted chemicals, including the ammonia produced by animals, and nor does it substantially affect carbonate hardness of the water. Other compounds that activated carbon has little or no ability to remove include stuff like calcium, carbon dioxide, fluoride, magnesium, nitrate, nitrite, phosphates, sodium, and iron.

Of course, it's important to use carbon correctly. Ideally, carbon should be placed after the mechanical filtration media in the filter, where water will flow through it with little restriction. Otherwise, the stuff will clog with debris and other solids, significantly reducing its available surface area for chemical adsorption. Make sense?

Oh, and in these scenarios, activated carbon does recruit biofilms and their constituent bacteria, becoming a sort of biological filter. So, although this could be seen as a sort of collateral benefit, if you let your carbon sit too long, in a strange twist of irony, the sudden removal of portions of the natural biological filtration could actually be counter-productive-cause a sudden decrease in water quality!

The reality, in my opinion, is that even carbon is not really a full-on "necessity", if you're on top of other aspects of husbandry, like water exchanges, etc. 

And what about filters in general?

When you break it down, a "filter" accomplishes the things which we discussed previously- Physical removal of materials from the water column, chemical adsorption/absorbtion, facilitates biological activity (ie, the growth of beneficial bacteria), and circulates and/or aerates the water.

Think about this: If we consider the functions that a filter unit/system does, it's not much of a stretch to conclude that a botanical method aquarium, replete with all of these leaves, seed pods, and such, functions in a way as the "filter."

Shiiiit. Woahhh! 💥


Yeah, my thinking has long been that you could actually consider the tank itself (or more properly, the botanical environment within it) as the"biological filter", and simply use aeration/surface skimming and/or circulation pumps to facilitate the gas exchange. Not exactly revolutionary, of course- but an idea that's often overlooked today.

Think about this:

The botanical materials present in our systems provide enormous surface area upon which beneficial bacterial biofilms and fungal growths can colonize. In addition to physically fragmenting botanical materials, these life forms utilize the organic compounds present in the water as a nutritional source.

Oh, the part about the biofilms and fungal growths sounds hauntingly familiar, doesn't it?

Let's talk about our buddies, the biofilms, just a bit more. One more time. Because nothing seems as contrary to many hobbyists than to sing the praises of these gooey-looking strands of bacterial goodness!

Structurally, biofilms are surprisingly strong structures, which offer their colonial members "on-board" nutritional sources, exchange of metabolites, protection, and cellular communication. They form extremely rapidly on just about any hard surface that is submerged in water.

When I see aquarium articles and videos in which biofilms are considered a "nuisance", and suggestions that it can be eliminated by "reducing nutrients" in the aquarium, I usually cringe. Mainly, because no matter what you do, biofilms are ubiquitous, and always present in our aquariums. They are perfectly natural. We may not see the famous long, stringy "snot" of our nightmares, but the reality is that they're present in our tanks regardless.

Attempting to remove them because they look "weird" to us is just...well...stupid!

And wasteful.

The reality is that biofilms are something that we as aquarists typically fear because of the way they look. In and of themselves, biofilms are not harmful to our fishes. They function not only as a means to sequester and process nutrients ( by our own hobby definition, a "filter" of sorts?), they also represent a beneficial food source for fishes. They are shockingly useful.

Now, look, I can see rare scenarios where disproportionately massive amounts of biofilms (relative to the water volume of the aquarium) can consume significant quantities of oxygen and be problematic for the fishes which reside in your tank. These explosions in biofilm growth are usually the result of adding too much botanical material too quickly to the aquarium. They're excaserbated by insufficient oxygenation/circulation within the aquarium.

These are very unusual circumstances, resulting from a combination of missteps by the aquarist. I have seen/heard of this happening literally 3-4 times in over 7 years of running Tannin Aquatics, and every single one was attributable to the misstep I just mentioned.

Typically, however, biofilms are far more beneficial than they are reven remotely detrimental to our aquariums.

Nutrients in the water column, even when in low concentrations, are delivered to the biofilm through the complex system of water channels, where they are adsorbed into the biofilm matrix, where they become available to the individual cells.  

Some biologists feel that this efficient method of gathering energy might be a major evolutionary advantage for biofilms which live in particularly in turbulent ecosystems, like streams, (or aquariums, right?) with significant flow, where nutrient concentrations are typically lower and quite widely dispersed.

Biofilms have been used successfully in water/wastewater treatment for well over 100 years! In such filtration systems the filter medium (typically, sand) offers a tremendous amount of surface area for the microbes to attach to, and to feed upon the organic material in the water being treated. The formation of biofilms upon the "media" consume the undesirable organics in the water, effectively "filtering" it! (extra credit "homework": Research "bioballs")

Biofilm acts as an adsorbent layer, in which organic materials and other nutrients are concentrated from the water column. As you might suspect, higher nutrient concentrations tend to produce biofilms that are thicker and denser than those grown in low nutrient concentrations.

Those biofilms which grow in higher flow environments, like streams, rivers, or areas exposed to wave action, tend to be denser in their morphology. These biofilms tend to form long, stringy filaments or "streamers",which point in the direction of the flow. These biofilms are characterized by characteristic known as  "viscoelasticity."This means that they are flexible, and stretch out significantly in higher flow rate environments, and contract once again when the velocity of the flow is reduced.

Okay, that's probably way more than you want to know about the physiology of biofilms! Regardless, it's important for us as botanical-method aquarists to have at least a rudimentary understanding of these often misunderstood, incredibly useful, and entirely under-appreciated life forms.

And the whole idea of facilitating a microbiome in our aquariums is predicated upon supplying a quantity of botanical materials- specifically, leaf litter, for the beneficial organisms to colonize and begin the decomposition process. An interesting study I found by Mehering, et. al (2014) on the nutrient sequestration caused by leaf litter yielded this interesting little passage:

"During leaf litter decomposition, microbial biomass and accumulated inorganic materials immobilize and retain nutrients, and therefore, both biotic and abiotic drivers may influence detrital nutrient content."

The study determined that leaves such as oak "immobilized" nitrogen. Generally thinking, it is thought that leaf litter acts as a "sink" for nutrients over time in aquatic ecosystems.

Chew on that for a few minutes...

Oh, and one more thing about leaves and their resulting detritus in tropical streams: Ecologists strongly believe that microbial colonized detritus is a more palatable and nutritious food source for detritivores than uncolonized dead leaves. The microbial growth which occurs on the leaves and their resulting detritus increases the nutritional quality of leaf detritus, because the microbial biomass on the leaves is more digestible than the leaves themselves (because of lignin, etc.).

And never forget our friends, the fungi!

Okay, great. I've just talked about decomposing leaves , biofilms, and fungal growths for like the 11,000th time in "The Tint"; so...where does this leave us, in terms of how we want to run our aquariums?

Let's summarize:

1) Add a significant amount of leaf litter, twigs, and botanicals to your aquarium as part of the substrate.

2) Allow biofilms and fungal growths to proliferate.

3) Feed your fishes well. It's actually "feeding the aquarium!"

4) Utilize a "filtration system" which you like, if any.

"So, what filter do you use, Scott?"

Personally, I use a lot of "all-in-one" tanks, which have a built in "filter compartment" in the back, which one could (if he/she/they desires) add chemical filtration media. I generally use...nothing in mine. Okay, well, maybe a small sachet of carbon.

But that's it. 

Again, I feel that it's far, far more important to facilitate biological processes in our tanks than to develop a sort of "dependency" on mechanical and chemical filtration systems. Learning to manage our systems naturally with water exchanges and careful stocking/feeding is far more important, IMHO.

Oh, and decent water movement/circulation and gas exchange. 

If you do your homework about some of the natural aquatic habitats which inspire our work, you'll find that the majority-not all, of course- have some water movement. They're usually not stagnant (although some are).

In an aquarium, we're well-advised to have some water movement, to facilitate gas exchange, provide a little "exercise" for our fishes (that sounded stupidly quaint, but you get the picture), and to avoid thermal, pH and/or nutrient layers in our tanks.

Gas exchange (the process in which carbon dioxide exits into the atmosphere and new oxygen from the atmosphere is dissolved into the water) is really important in aquariums, and aeration from filter returns helps facilitate the process. Fish need oxygen (like 5-6 parts per million) in their water. Now, it's not mandatory to have airstones, filter returns, or surface skimmers to create surface agitation, but it sure helps.

I suppose you could say that the "purpose" of aeration is to "break up" the surface of your water. You’re not going to separate the oxygen molecules from the water and force a gas exchange within the water column, by cranking up an ayirstone- that's not what it does. But it will help break up the surface boundary layer to facilitate gas exchange. I guess that's why I love surface skimmers, or filters which skim the surface boundary layer.

And yes, a wide aquarium with lots of open surface area can accomplish gas exchange without supplemental circulation, too. Not as efficiently as mechanical means, but it works. I mean, hobbyists did this for a generation before air pumps and filters came along, so...


So, yeah- use what works for you, benefits your fishes, and creates the best outcomes for them. There are so many approaches, any of which could work for you. It's no longer a "cookie cutter" recipe for success in the aquarium world; it's okay to experiment a little.

Just understanding that the aquarium is an ecosystem unto itself will help you make more informed, less restrictive decisions about what works best for you and your tank.

The concept of "filtration" is constantly evolving. To me, besides the obvious benefits of utilizing media which can remove impurities and organics on a continuous basis from the aquarium, the most important ones are circulation and gas exchange/aeration. Of course, there are lots of different viewpoints on this topic!

Like so many things that we do in our hobby speciality, considering filtration and its place in our work requires that we look at things from a variety of angles. It's never just a "cut-and-dry" recipe for doing things a certain way; everything requires a little more consideration, doesn't it?

It does.

Stay focused. Stay thoughtful. Stay curious. Stay proactive...

And always Stay Wet.


Scott Fellman

Tannin Aquatics 



April 18, 2022


A Fine "Mess..."

Okay, we need to talk about something...again.

There is this mindset in the hobby that aquariums which embrace the use of natural materials like leaves and seed pods are..."messy" or "dirty." This is not only a completely incorrect assertion- it's just sort of stupid. As we have pointed out for 7 years now, Nature is anything but a clean, organized place.

Yet, for some reason, those not in the know seem to love inferring that aquariums set up with large amounts of botanical materials (intended to be colonized by biofilms and fu gal growths prior to decomposing) are "messy."

This is understandable, I suppose; but to those of us familiar with this methodology, this assertion is kind of laughable.

As you know by now, I am pretty much near-obsessed with the idea of allowing a botanical-style aquarium to "evolve" with little interference on the part of the aquarist. With botanical-method aquariums, I personally believe that they can better handle evolving on their own more so than many typical systems...Not that I'd want to just "let a tank go", mind you...

I'm a fairly diligent/borderline obsessive maintenance guy. I love my weekly water exchanges. However, I think it's very important to understand the reason why we create aquariums like this. What is the goal? What are we trying to accomplish? If we make an effort to understand the way the natural habitats we are enamored with function, it becomes way easier to manage them in a more confident manner.

Hobbyists unfamiliar with our processes and ideas will call this a mess.

We call it "natural."

I mean, when you think about it, the natural, botanical-method aquarium is deliberately set up to replicate a wild aquatic habitat where all of this stuff is taking place already. Leaves, seed pods, etc. are more-or-less ephemeral in nature, and are constantly breaking down in these environments.

Colonization by biofilms and fu gal growths, as well as fragmentation and decomposition of botanical materials is continuous. 

I love the fact that this approach is still seen as somewhat "contrarian" to the more conventional aquarium interpretation of a "natural" aquarium, despite the growing global popularity. I'm fascinated by the "mental adjustments" that we need to make to accept the aesthetic and the processes of natural decay, fungal growth, the appearance of biofilms, and how these affect what's occurring in the aquarium.

So, when I hear our aquariums criticized as "messy" by the (let's call them what they are) uninformed, I sort of laugh. They literally have no idea what they're talking about. 


This is not only a completely incorrect assertion- it's just sort of stupid. As we have pointed out for 7 years now, Nature is anything but a clean, organized place.


 And really, the idea of "doing it like Nature does" has led to an idea which I've been playing with not only at the moment, but for some time now:

In situ "curing" of wood and botanicals.

Something that indeed, goes against our "typical" practice, and certainly is different than my more "conventional" approach of boiling leaves and pods, and curing wood in a separate container of water. Rather, just "rinse and drop!" Hardly precise. And rather at odds with even our own"conventions" and practices that we've touted here!

Yet, playing with this approach has given me some of my favorite tanks ever!

It takes time, and a willingness to wait and observe and open yourself up to a bit of a "mess" at the beginning- at least in the "conventional" aquarium sense. To me, it seems like by doing this, you're actually letting Nature do Her thing!

It's not revolutionary...However, it is "evolutionary" for me, in that it more completely embraces my philosophy of building up a microcosm from scratch in an aquarium. This approach might be the ultimate expression of that. Think about this: Why do we "cure" wood outside of our display aquariums?

Well, typically, it's because we don't want the silt, sediment, biofilms and fungal growth which inevitably appears on wood when we submerge it for the first time, in our tanks.  I get that. And we want leaves and botanicals to sink right to the bottom. Also, not everyone is fond of the tannins released during this process, too. And the other materials, which we (present company include) have historically referred to as "organic pollutants", are seen as "undesirable." 

I get all of those.

Yet, if we give these materials a good rinse, maybe a scrub, or even a light boil, and then let 'em settle into the there any harm?

My experience tells me that there isn't. 

Yeah, when you really think about it, all of these materials and compounds exuded by wood and botanicals are food to various organisms, right? And when we remove this stuff, we're essentially depriving someone along the food chain their sustenance, right?

So, maybe there is some value to curing stuff "in situ" under carefully monitored circumstances. What will likely happen?

Well, you'll recruit a lot of biofilm and fungal growth initial. Maybe get some cloudy water for a bit as materials leach out and either settle, or are consumed by a growing population of microorganisms within the tank.

Yeah, the growth and proliferation of organisms of all types will contribute not only to the biological stability of the system over the long haul, I believe that it'll form the basis of a literal "food web" in the aquarium. Allowing this to happen, despite our human impatience- or even our initial aversion to the looks of the process- enables us to truly embrace the function of Nature.

In Nature, terrestrial materials covered by water are the basis for almost every aquatic ecosystem. The processes of decomposition and colonization- and utilization- of these materials by an enormous variety of organisms- is truly what "powers" these ecosystems. 

It works exactly the same in an aquarium...If we let Nature do her work without excessive intervention.

Yeah, let it be. Literally.

It'll take a while before it's "ready" for fishes. Is that a downside? I don't think so.

Now, sure, I realize that an aquarium is not an open, natural aquatic system, and that there are different inputs and export mechanisms, but in principle, an aquarium is subject to natural "laws" and functions like many other natural aquatic systems, right?

I'm really having trouble grasping exactly what the problem is with this approach- other than the obscene amount of patience we have to deploy as hobbyists waiting for our tanks to settle in and be "just right" for fishes. "Messy?"  Is it just the look? Is it because we've always been told NOT to start aquariums this way? Maybe? I mean, the aquariums that we play with own our world are not exactly "conventional", right?

So what should the way we establish them be?

It just takes longer, that's all.

Aquarium hobbyists have (by and large) collectively spent the better part of the century trying to create "workarounds" or "hacks", or to work on ways to circumvent what we perceive as "unattractive", "uninteresting", or "detrimental." And I have a theory that many of these things- these processes- that we try to "edit", "polish", or skip altogether, are often the most important and foundational aspects of botanical-style aquarium keeping!

It's why we literally pound it into your head over and over here that you not only shouldn't try to circumvent these processes and occurrences- you should embrace them and attempt to understand exactly what they mean for the fishes that we keep.

They're a key part of the functionality.

Now, I've had a sort of approach to creating and managing botanical-style aquariums that has drawn from a lifetime of experience in my other aquarium hobby  "disciplines", such as reef keeping, breeding killifish and other more "conventional" hobby  areas of interest. And my approach has always been a bit of an extension of the stuff I've learned in those areas.

I've always been fanatical about NOT taking shortcuts in the hobby. In fact, I've probably avoided shortcuts- to the point of making things more difficult for myself at times! Over the years, I have thought a lot about how we as botanical-method aquarium enthusiasts gradually build up our systems, and how the entire approach is about creating a biome- a functional little closed ecosystem, which requires us to support the organisms which comprise it at every level.

Just like what Nature does.

It takes a little bit of mental shifting, a little bit of courage, a bunch of attitude, and the ability to overlook some aesthetics which you've been programmed by the hobby to be freaked out about.

You up for that? 

Oh, and for those who think that what we do is "messy?" Chew on this thought:

It's perfectly okay to make a little "mess" sometimes. It can lead to something beautiful. THAT is a fine "mess", indeed.

Stay brave. Stay open-minded. Stay creative. Stay patient. Stay engaged...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


April 14, 2022


Iagpo, Igarape, Varzea...and the abundance within them

If you've followed Tannin Aquatics for any length of time, you know all to well that we're pretty much obsessed with some of the ephemeral aquatic habitats of South America, ranging from flooded forests to seasonally inundated grasslands, and even temporary streams which flow through the forest.

We're drawn to these habitats because they are inspiring examples of how the terrestrial and aquatic environments work together. 

In these wild habitats, the leaves, branches, soils, and other botanical materials which are present during the dry season, remain in place, or are added to by dynamic, seasonal processes. For the most part, the soil, branches, and a fair amount of the more "durable" seed pods and such remain present during both phases.

The formerly terrestrial physical environment is now transformed into an earthy, twisted, incredibly rich aquatic habitat, which fishes have evolved over eons to live in and utilize for food, protection, and complex, protected spawning areas. 

All of the botanical material-shrubs, grasses, fallen leaves, branches, seed pods, and such, is suddenly submerged; often, currents re-distribute the leaves and seed pods and branches into little pockets and "stands", affecting the (now underwater) "topography" of the landscape.

Leaves begin to accumulate. Detritus settles on the substrate, leaves, and fallen branches.

Soils dissolve their chemical constituents- tannins, filmic, and humic acids- into the water, enriching it. Fungi and micororganisms begin to colonize on the fallen tree trunks, seed pods, and leaves, breaking down the materials. Biofilms form, crustaceans and aquatic insects multiply rapidly. Fishes are able to find new food sources; new hiding areas to spawn.

Life simply flourishes.

And it is part of a sequence. A pattern...A journey. Perhaps what could best be called an evolution- which Nature has carefully set up and managed over eons. 

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


Igapo forests have a pretty significant amount of trees; one study found that over 30 species of trees are found in these areas, creating coverage of something on the order of 30%, and are known to have soils that are acidic in nature, yet low in nutrient content (because they don't receive a seasonal influx of nutrients like regions called "varzea", which are flooded by sediment-laden "whitewater" rivers).

The water depth in these habitats can vary from as little as 6-8 inches ( 15.24cm- 20.32cm), to almost 20 feet (6.96m)!  And of course, they have a lot of tannins, filmic, and humic substances in them from all of the soil and plant materials.

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

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

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

These inundated forest floors are fascinating subjects for aquarium replication! You get all sorts of interesting interactions, interdependencies, and relationships in one convenient package, lol.

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

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

Replicating the dynamics and some of the characteristics in these habitats is something that we've been experimenting with for several years, with impressive and intriguing results.

We've tackled our "Urban Igapo" idea a bunch of times here in "The Tint", with the technique being described and studied quite a bit. Now, the repetition of wet and dry "seasonal cycles" in the aquarium, although fascinating and the most novel takeaway from this approach, is but one way to apply the idea of evolving a "dry forest floor" into an aquatic habitat.

This is one of the most incredible and fascinating ecological dynamics in Nature, and it's something that we as a hobby have not attempted to model to any extent, until we started messing around with the idea of replicating it around 2017. Again, we're not talking about replicating the 'look" of a flooded forest after it's been flooded...That has been done for years by hobbyists, particularly in biotope design contests. An "aquascaping" thing. 

This is a bit different. 

We're talking about actually replicating and flooding the forest floor! Replicating the cycle of inundation. It's a functional approach, requiring understanding, research, and patience to execute. And the aesthetics? They will follow, resembling what you see in Nature. And that's certainly "different" than what many might expect. But the primary reason we've been playing with replicating these habitats is NOT for aesthetics... 


The approach and process is straightforward: You utilize a sedimented substrate (um, yeah, we do make one 😆) to create a "forest floor." And then, you add leaves, botanicals, and perhaps, some terrestrial grass seeds, and even riparian plants.

You'd set whatever "hardscape" you want- driftwood, etc. in place. Of course, you'd have to water your little forest floor for some period of time, allowing the vegetation to sprout and grow. Based on the many times of played with the "Igapo" idea, this process typically takes around 2-3 months to establish the growth well. 

And then what? Well, you'd flood it!

You could do this all at one time, or over the course of several  days or weeks, depending upon your preference. I mean, shit- you've waited a couple of months just to add water to your tank...what's another few days? 😆 Now, sure, there's a difference between a 5-gallon tank and a 50- gallon tank, and it takes a lot longer to fill, so it's up to you how you want to approach this!

So, yeah, the execution of this type of aquarium is not all that difficult.

And what you'll initially end up with is a murky, tinted environment, with little bits of leaves, botanicals, and soil floating about. Sounds like a blast, huh? And when you think about it, this is not all that different, at least procedurally, from the "dry start" approach to a planted tank...except we're not talking about a planted tsmnk here.. I mean, you could do aquatic plants...but it's more of a "wholistic biome" approach...

The interesting thing about this approach is that you will see a tank which "cycles" extremely quickly, in my experience. In fact, Iv'e done many iterations of "Urban Igapo" tanks where there was no detectible "cycle" in the traditional sense. I don't have an explanation for this, except to postulate that the abundance of bacterial and microorganism growth, and other life forms, like fungal growths, etc., powered by the nutrients available to them in the established terrestrial substrate simply expedites this process dramatically.


That's my theory, of course, and I could be way, way off base, but it is based on my experience and that of others in our community over the past several years. I mean, there is a nitrogen cycle occurring in the dry substrate, so when it's inundated, do the bacteria make the transition, or do they perish, followed by the very rapid colonization by other species, or..?


An underwater biome is created immediately with this approach. Doing this type of "transition" is going to not only create a different sort of underwater biodiversity, it will have the "collateral benefit" of creating a very different aesthetic as well. And yeah, it's an aesthetic that will be dictated by Nature, and will encompass all of those things that we know and love- biofilms, fungal growth, decomposition, etc.

From an aquarium perspective, the unique ecology of these types of habitats lend themselves very well to aquarium replication. Because they encourage an explosion of life forms- a "bloom", if you will- at all levels, something which we should all celebrate. 

Nature celebrates "The Bloom", too.

And yeah, there is something truly remarkable about natural processes playing out in our own aquariums, as they have done for eons in the wild.

Remember, it's all part of the game with a botanical-influenced aquarium. Understanding, accepting, and celebrating  that "the bloom" is all part of that "mental shift" towards accepting and appreciating a more truly natural-looking, natural-functioning aquarium. The "price of admission", if you will- along with the tinted water, decomposing leaves, etc., the metaphorical "dues" you pay, which ultimately go hand-in-hand with the envious "ohhs and ahhs" of other hobbyists who admire your completed aquarium when they see it for the first time.


The reality to us as "armchair ecologists" is that the presence of these organisms in our aquariums is beautiful to us for so many reasons. It's not only a sign that our closed microcosms are functioning well, but that they are, in their own way, providing for the well- being of the inhabitants! 

An abundance, created by the explosion of life in our tanks, filed by botanical materials.

The "mental stretches" that we ask you to make to accept these organisms and their appearance really require us to look at the wild habitats from which our fishes come, and reconcile that with our century-old aquarium hobby idealization of what Nature (and therefore our "natural" aquariums) actually look like.

Sure, it's not an easy stretch for most. Seeing it in Nature and seeing it in your home aquarium are two very different things...

It's likely not everyone's idea of "attractive", and you'd no doubt freak out snobby contest judges with a tank full of biofilms and fungi, but to most of us, we should take great delight in knowing that we are providing our fishes with an extremely natural component of their ecosystem, the benefits of which have never really been studied in the aquarium in depth.

Why? Well, because we've been too busy looking for ways to remove the stuff instead of watching our fishes feed on it, and our aquatic environments benefit from its appearance!

We've had it all wrong, IMHO. 

It's okay, we're starting to come around...

Welcome to Planet Earth.

Yet, there are always those doubts...and some are not willing to sit by and watch the "slime" take over...despite the fact that we know it's okay...

Celebrate "The Bloom." Savor the abundance.

Blurring the lines between Nature and the aquarium, from an aesthetic sense, at the very least- and in many respects, from a "functional" sense as well, proves just how far hobbyists have good you are at what you do. And... how much more you can do when you turn to nature as an inspiration, and embrace it for what it is.

The same processes which occur on a grander scale in Nature also occur on a "micro-scale" in our aquariums. And we can understand and embrace these processes- rather than resist or even "revile" them- as an essential part of the aquatic environment.

And the beauty of it all is that your aquarium will evolve over time, as the botanical materials break down and impart their chemical constituents into the water. The water clears, taking on a deep tint..all of the aesthetics that we seem to crave when we get into this type of aquarium in the first place.

It just takes a little time...and a lot of patience on your part.

So it really doesn't matter which habitat you're attempting to replicate in your aquarium- it's more of a matter of how you do it. And how you react when you do it.

Either way, as the sayings goes...just DO it.

Stay creative. Stay inspired. Stay observant. Stay patient. Stay bold...

And Stay Wet.


Scott Fellman

Tannin Aquatics


April 13, 2022


Working with "the establishment!"

The last few pieces we've shared here on "The Tint" have apparently really resonated with a lot of you! We've received a lot of comments, questions, and thoughts about deploying patience and observation during the establishment of new botanical method aquariums. I'm very pleased to hear this, because the fact that so many people have been "buying in" to these philosophies is indicative a of a "mental shift" of sorts in our hobby movement.

As I've said numerous times here, botanical method aquariums are not an "aquascaping style"- they are a representative of a methodology which embraces natural materials and processes to "finish" what we start- to not only help create and enrich the ecosystem- but to change the aesthetics as it does.

This "handing off" to Nature to take over what we've started in the earliest days of our tanks is a hugely important step in what we do. In fact, I dare say that this is a foundational part of our approach. I can't stress it enough. And honestly, I admit that it's really hard to do sometimes. You've earnestly done the work to get your new aquarium up and running, and then it starts getting a bit turbid and tinted, and biofilms and fungal growths start appearing- and we tell you to "keep your hands" out and just...enjoy!

For those patient souls who admire and appreciate the process of Nature, and therefore embrace the aesthetics as the aquarium establishes itself, it's a time to savor all that is unfolding. For those who are perhaps a little less patient, maybe unsure, and eager to see clear (but tinted) water and perhaps a less "disheveled" start to their new tank, it can test their patience and faith in the approach for sure!

Interestingly, one of the most frequently asked questions that we receive about newly established botanical method tanks is how to get them to look "broken in" and "established" more quickly! 

Okay, let me be clear about a few things. I don't advocate circumventing the processes which help establish our botanical method aquariums. I do, however, understand that many enjoy the "look" of these tanks, and want to enhance the aesthetic experience whenever possible.

The strange inconsistency is that it would be better to embrace the aesthetics which arise when we create these types of tanks. So my advice on how to get the "look" you like is to go "all-in" and embrace the extensive use of the materials which we use to create them.

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

"Well, what are they, Fellman?" 

So you could use some botanicals and partially decomposed leaf litter, substrate, and even water from an established botanical-method tank to give you a bit more of an "evolved" vibe and definitely some microbial populations and therefore, some function. This is completely consistent with the concept of adding sand from an established, healthy aquarium, which has been used by aquarists for decades. 

And, if doing this for purely "functional" reasons as opposed to just trying to "hack" the "look"- I can actually see tremendous merit to this idea. Hell, adding sand or gravel/decomposing leaves and such from an established tank to "jump-start" a new one has been standard practice in marine aquariums for decades, and in freshwater as well.

Doing this with botanical materials- rich with detritus, biofilms, fungal growth, and beneficial bacteria- is simply the botanical-style version of this time-honored process, right? It makes perfect sense.


Yet, there is no substitute for patience and the passage of time.

Looking back on some of my favorite tanks that I've executed in the past few years, even though they look awesome from the start, it becomes increasingly obvious to all that these systems really don't hit that complete "look and feel" that we expect until long after they have evolved naturally...however long that is.

Stuff needs to acquire a "patina" of biofilm, a "stain" from the tannins, and decomposition of botanical materials needs to really begin before one of these systems turns "functional" as well. 

It takes time. Fungal growths establish. Bacterial populations grow. 

Every new botanical-style tank looks cool from day one...A lot of people love the clean and fresh-looking leaves, and seed pods that are squeaky clean. More and more of of us love the look of softening and decomposing leaves and botanicals. And yet, the long-established systems are the ones that really stand out.

After 6 months, that's when things get really special.


That's when the bulk of the "settling in" is done. The bacterial, fungal, and microorganism populations have increased, and nutrient imports and exports have balanced out and stabilized. The tank looks great, smells earthy and pleasant, the substrate is rich and ecologically diverse, and the fishes take on a very relaxed demeanor.

I've long held that my fave botanical-style, blackwater aquarium of all was the one I did about 3 years aquarium utilizing mangrove wood, extensive leaf litter, and catappa bark throughout. This is probably the only tank in recent years that I've truly regretted changing and moving on from! 😂 

And it wasn't all sexy and dark and established-looking from the get-go.


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

However, a few months in, biofilms started forming. The wood acquired that "patina" we talk about so much. Leaves and botanicals broke down...And the water took on the most earthy-looking, deeply mysterious color I've seen in a blackwater aquarium. A very slight "turbidity" or "flavor" as one of my friends called it- that was as compelling as it was beautiful.

Yeah, by some standards, the water in the tank could be described as almost "turbid"- taking on an appearance as though there were fine materials in the water column. Yet, the tank had a real magical appearance with the LED lighting; the fishes were as colorful, relaxed and happy as any I've ever seen, and the water parameters were spot-on and consistent for as long as the tank was set up. IN fact, I had three spawns of Rummy Nose Tetras in that tank!

This tank had a certain "something":

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

In Nature, many habitats go through periods of time where they are inundated by a flow of sediments, detritus, etc., and this has a big impact not only on how they function and support the life forms which reside in them, but in how they look as well.

This is very analogous to the way in which our botanical method aquariums "break in" and establish themselves that it's not even funny! Many of the same ecological and hydrological processes which impact wild habitats appear to shape our botanical method tanks at home, too.

And it is part of a sequence. A pattern...A journey. Perhaps what could best be called an evolution- which Nature has carefully set up and managed over eons. 

In our own aquarium work, we can replicate this sequence and's not that hard to do. The really difficult part is the waiting. Acquiring the patience that we must deploy as we watch our aquariums evolve, uninterrupted- under the steady hand of Nature.

That's the magic.

It's a process- the part of the journey which every botanical-method aquarist needs to embrace and understand. And sure, if you can accept the "look" during the "establishment phases"-  

Of course, an aquarium which utilizes botanicals as a good part of its hardscape follows a set of phases, too. And I've found that once a botanical method aquarium (blackwater or brackish) hits that sort of "stable mode", it's just that- stable. You won't see wildly fluctuating pH levels, increasing nitrates, phosphates, etc. To a certain degree, the aquarium has achieved some sort of "biological equilibrium."

Now, one thing that's unique about the botanical method approach is that we tend to accept the idea of decomposing materials accumulating in our systems. We understand that they act, to a certain extent, as "fuel" for the micro and macrofauna which reside in the aquarium. The idea of leaving this material in place over the long-term is a crucial component of this approach, IMHO.

When we do that- when we make those mental shifts and accept that our aquariums aren't really "finished" in 5 days- or 50- we have suddenly begun to understand this whole "botanical-method aquarium thing."

Suddenly, the day-to-day appearance of the aquarium during its establishment phase is not something which you "endure"- it becomes an intriguing part of the journey. Yeah, a mental shift of the highest order- appreciating your aquarium during every phase of its existence.

That's how you work with "the establishment..."

Stay strong. Stay committed. Stay creative. Stay bold...

And Stay Wet.


Scott Fellman

Tannin Aquatics