December 05, 2018


The names may have changed...but the song remains the same...

Things are changing fast.

The world of blackwater/botanical-style aquariums is exploding, with new techniques, applications, and ideas...


And along with the new ideas, comes new interests. New excitement. New breakthroughs. And new responsibilities that we, as "thought leaders" (hey, YOU called us that!) in this tinted world, need to accept.

We've been making changes...We're going be making tons of changes this year.

You might have noticed that, in addition to the evolving new look of our site, we've changed most of the names of our botanicals.


Now, why would we do this? Everything has been going amazing. We have a growing global following, all the "cool kids" are dabbling with our stuff- the brand is exploding...Why would we do something radical like that?

Well, it's simple. I mean, I think it's pretty simple.

When we first started Tannin, it was fun to sort of create a "flavor" for our site and come up with exotic names for the materials we sourced. We made up a lot of fun Portueguese names for the botanicals. Why Portueguese? Because that's the language spoken in Brazil, where there happens to be that cool region called "Amazonia" that we're kind of intrigued by, and...

Well, yeah- it made sense at the time. Helped define us. Distinguished this stuff. Helped popularize botanicals. Romanticized it a bit.

But here's the thing.

It was kind of...stupid.

What? You heard me.

Let me digress.

I came from the world of reef aquarims and coral propagation...You know, the expensive, hyped $100-per-square-centimeter coral frags that have, well- silly names and equally silly prices. I used to laugh at that stuff. The names...the over-romanticizing of them...

Yet, in an odd way, it sort of made sense to do this with botanicals to create more interest in them initially- to make 'em more relatable; to give context and identity...

And it did. For a while.

In fact, I think- I think- we were actually the first to even utilize the term "botanicals" to describe this stuff...I don't think that, prior to 2015, you even heard about botanicals described as..."botanicals!"

So I think it's kind of cool that it perhaps helped get things more popular...

Yet, at times,  I kind of wish that I "kept it real" from the start, because not only are the actual names and scientific ones intriguing, they're more helpful when you're the real hardcore type, trying to figure out what belongs in a specific aquarium...That sort of thing! However, it did serve to create a "vibe" and a buzz around Tannin and what we do initially...Fostering new excitement in a hobby sector that was obscure at best, and virtually non-existent at worst.

Fast forward to late 2018, and we have a full-blown hobby movement with botanicals! People all over the world are into this! We're at a new "maturity" level in the practice of utilizing botanicals and creating more natural, "functionally aesthetic" aquariums...And with this "maturity" comes more responsibility for us as a "thought leader" in this area. A responsibility to educate, inspire, and inform. A responsibility to be more accurate and authoritative.

Yeah, time to ditch the cutesy names.

It was getting a bit too much, even for me. Although it might be a bit easier to pronounce and remember the cute names, it is better in the long run to embrace the more accurate nomenclature. This botanical movement is bigger than any one company. More important than any one brand or person. 

We offer botanicals. Nature "makes" them. And we are a brand which stands for something. And the brand supersedes the individual "product names." And the botanical-style/blackwater aquarium movement supersedes any one brand...

And a few other vendors doing this botanical thing now, too- which is great. Where it is a bit funny, however, is that a few of 'em are using the very names that we coined to describe similar materials that they are offering-even though they're essentially "meaningless"...And in at least one instance, someone "translated back" our silly botanical names into English to name his offerings...A 360 degree cycle of absurdity. We're not going to continue to perpetuate this silliness. 

It was inevitable, I suppose.

And I realized that if I didn't step up and show some real leadership and confidence now, this could turn into the world's goofiest "coral frag swap" all over again, with out of control names, absurd claims, "limited edition" botanicals and such. And this wouldn't be helpful... I mean, here we are at Tannin, with over 700 blogs all about the most arcane aspects of the botanical/blackwater aquarium hobby- pushing and poking around the hobby in lots of crazy ways- hopefully educating and inspiring...

And then, there we were, calling a Dregea volubillsis pod a "Concha Pod."

Cute. Entertaining. But not helpful. 

As I've said a million times, no one invented this stuff. 

We curated it. Studied it. Loved it. Sourced it. Shared it. But we didn't invent it. NO ONE DID.

Now I admit, I am rather fond of a lot of the names we came up with...some of these materials simply never had a "common name", so we invented ones that fit our vibe. When I embarked on this road to transitioning to more appropriate names,  it took a lot of research and talking to my suppliers in the countries of origin to find out if there is a common or popular name for some of these materials..

And when applicable, we'll use them. Or, we'll go by the genus/species name and call them "_______ Pods." 

It will be a bit confusing at first, I admit.

And I could have gradually phased into it. But in the end, if you want to continue to be the leader, you need to act like one. We cut a path into this area before there was one...Now it's time to push out a little farther. As you've likely already noticed, we've started to change our look- and now we're upping our game all around. 

Time to grow up.

And we're doing this "cold turkey"- for better or worse. Just a few more to change...

Now, I admit- some of you may not like it at all. Some of you will cheer..and some of you couldn't give a ----.

Ahh, the risks you take when you want to lead.

What's in it for YOU? 

Well, after the initial confusion and realization that "That is now THIS", you get to have a better knowledge of the botanicals you use in your tanks. You can research places of origin, the growing habits of the plants they come from, etc. And when you learn about these materials, you can help unlock more ideas about how best to utilize them in our aquariums.

Or, you can just enjoy them, look at the pic for ID when you purchase them, and learn along with us to use their more correct names.

Simple as that.

So, if there IS a common name- ie; "Monkey Pot", "Coco Curl", etc.- or a logical common descriptor- like "Jacaranda Pod", Alder Cone, etc.- we'll use that. Some old faves, like "Jungle Pod" might hang on for a bit. However, some really popular ones, like "Savu Pod", have simply mutated into "Cariniana Pod" (the genus name).

Maybe not quite as sexy...or even as memorable.

I mean "Clown Killie" is probably easier to remember and more "fun" than Epiplatys annulatus, but in the long run, the hobby- and the hobbyist, benefit more from the accurate description, IMHO. I mean, you could probably call a number of species "Clown Killie", creating far more confusion than education and progress.

However, we'll all be better off for it in the long run. And the picture will always help,  just like it did when we first marketed Aegle marmelos as "Sino Xicara."

And what about our competitors who "appropriated" our absurd botanical names? I get a lot of questions about this from you guys. My answer? Maybe they'll keep 'em for a while...or simply do what some of them been doing all along, and just copy the new naming convention...I suppose it's inevitable; likely better for the hobby in the long run, too. As one of my friends told me, they can copy names, but they can't copy our brand; what it stands for; what we've done.

That's pretty satisfying!


Here's a list of some of the most noticeable changes we've made:

"Savu Pod"= Cariniana Pod 

"Capsula Pod"= Dysoxylum Pod

"Casulo Pod"= Kurrajong Pod

"Lampada Pod"= Mokha Pod

"Sino Xicara"= Kuruchi Pod

"Encontro Pod"= Kielemeyera Pod

"Concha Pod"= Dregea Pod

"Estalo Pod"= Parviflora Pod

"Manta Pod"= Cuspa Pod

"Flor Rio Pod"= Latifolia Pod

"Teardrop Pod"= Pyrifolium Pod

"Tartaruga Pod"= Jacaranda Pod

"Ceu Fruta"= "Skyfruit" Pod

"Rio Fruta"= Nypa Palm Pod

"Ra Cama Pod"= Afzelia Pod

"Pequeno Pod"= Schima Pod

"Rio Passaro Pod"= Nypa Palm Flower

"Milho Pod"= Pandanus Pod

"Descasca Pod"= Swietenia Pod


Yeah, WAAAY less romantic. Way less sexy. Way more accurate. Way more useful.

Other than that, not much has changed, lol.

Song remains the same.

So, keep pushing the limits. Keep learning new things. Keep playing with botanicals and all of the fun ideas that go with them.

Stay curious. Stay excited. Stay creative. Stay bold. Stay innovative...

And Stay Wet.


Scott Fellman

Tannin Aquatics




December 04, 2018


The art of "Active Monitoring..."

When we think about our botanical-style aquariums over the long term, they will evolve in many ways, much like a natural river or stream, without much intervention on our part.

As water flow decreases, plants might grow differently. As the substrate begins to take on a "life of its own",  with more life forms growing in its matrix, fishes will forage for supplemental food items in it. 

As wood begins to soften, releasing more tannins into the water, the water darkens. Leaves and botanicals start to decompose, enriching the environment with humic acids, tannins, and other organic materials, further spurring plant growth, etc. Algae, although often dreaded, grow based on the available nutrients, waxing and waning. Biofilms emerge, providing supplemental food for the aquarium's inhabitants.

And you'll be involved. You'll interact with your aquarium; play some role in it's evolution, progress, and growth. Hopefully, you'll strike a balance between too much and too little. Or better yet- an understanding as to why they appear, and what it really means to your tank. No two aquariums are alike, and this is a foundational piece of aquarium keeping.

All part of a little "dance", that, although important to monitor, is not necessarily something that we as hobbyists have to intervene in. We do quite a bit when we simply perform our regular water exchanges, filter media replacements/cleanings, and occasional plant trimmings.

In fact, I sometimes wonder if that is ALL we need to do?

So why not simply enjoy what's happening in your aquarium as it evolves?

I know that I perennially overthink stuff, instead of merely enjoying it. "Active monitoring" is a great way to run a tank, IMHO. You do the necessary functions to keep things stable and consistent, and little more.

Just observe; enjoy.

Watching a display aquarium evolve and sort of "find itself" naturally over time is proving to be one of the most enjoyable discoveries I've made in the hobby in decades. By simply following established maintenance routines, and monitoring what's occurring in the tank, as opposed to constantly trying to "pre-empt" problems, I've had more stability, more growth...more success than ever before.

Accepting that there is most definitely a "dance" in our aquariums, and becoming an "active monitor" instead of an "active intervener" has added a new and rewarding aspect to my love of the hobby.

I think that it not only makes you a more engaged hobbyist, it gives you a remarkable appreciation for the long term evolution of an aquarium; an appreciation for the pace by which nature operates, and the direction which your aquarium goes.


"Monitoring" versus "intervening"...An interesting, if not critical- choice on the path towards aquarium success.

Stay focused. Stay observant. Stay patient. Stay engaged...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

December 03, 2018


Looking under the leaves...extracting some useful blackwater knowledge!

As we delve deeper and deeper into the dark and seedy (LOL) world of botanicals, it's kind of interesting to learn a few things about them that you might not know. Literally, diving just underneath the surface, you can find a lot of good information which can help you create and maintain more successful blackwater, botanical-style aquariums.

And a lot of this starts with an understanding of the botanicals themselves, and how they impact the aquatic environments in which they end up.

Many seed pods and similar botanicals contain a substance known as lignin. Lignin is defined as a group of organic polymers which are essentially the structural materials which support the tissues of vascular plants. They are common in bark, wood, and yeah- seed pods, providing protection from rotting and structural rigidity.

In other words, they make seed pods kinda tough.

That being said, they are broken down by fungi and bacteria in aquatic environments...Here's a thought to consider: Inputs of terrestrial materials like leaf litter and seed pods can leach dissolved organic carbon, rich in lignin and cellulose.  Factors like light, mineral hardness, and the bacterial community affect the degree to which this material is broken down into its constituent parts in this environment.

Hmm...something we've kind of known for a while, right?

So, lignin is a major component of the stuff that's leached into our aquatic environments, along with that other big "player"- tannin.

Tannins, according to chemists, are a group of astringent biomolecules that bind to and precipitate proteins and other organic compounds. They're in almost every plant around, and are thought to play a role in protecting the plants from predation and potentially aid in their growth. As you might imagine, they are super-abundant in leaves. In fact, it's thought that tannins comprise as much as 50% of the dry weight of leaves!

And of course, tannins in leaves, wood, and plant materials tend to be highly water soluble, creating our beloved blackwater as they decompose. As the tannins leach into the water, they create that transparent, yet darkly-stained water we love so much!  In simplified terms, blackwater tends to occur when the rate of "carbon fixation" (photosynthesis) and its partial decay to soluble organic acids exceeds its rate of complete decay to carbon dioxide (oxidation).

These waters tend to be home to much, lower populations of insects and microorganisms as a result of the presence of tannins, but, as we've discussed before, they still host abundant life and different kinds of "food webs" to support the resident fishes and aquatic fauna which reside in them.

Interesting tidbit of information from science: For those of you weirdos who like using wood, leaves and such in your aquariums, but hate the brown water (yeah, there are a few of you)- you can add baking soda to the water that you soak your wood and such in to accelerate the leaching process, as more alkaline solutions tend to draw out tannic acid from wood than pH neutral or acidic water does. Or you can simply keep using your 8.4 pH tap water! 

"ARMCHAIR SPECULATION": This might be a good answer to why some people can't get the super dark tint they want for the long term...If you have more alkaline water, those tannins are more quickly pulled out. So you might get an initial burst, but the color won't last all that long...

As we know from my repeated rantings here, blackwater aquatic systems tend to have low conductivity and low levels of dissolved solids. Or, more precisely, a low content of suspended sediments, but a high content of dissolved organic matter. Soils and detritus provide the fuel for the aquatic eco systems in these rivers, such as the podzols that we've discussed here before.

And fishes, of course, actually play a part in the process of "evolving" the blackwater ecosystem. 

And, in "iagapos "(those seasonally flooded forest areas which lead to blackwater environments), these soils are conducive to good terrestrial plant growth. Fishes which reside in these habitats feed off of the materials, like fruits and seeds, which fall from the trees, or otherwise end up in the water during periods of inundation.

Interestingly, seed dispersal by fish (a process known technically as "ichthyochory") is thought to play an important role in the maintenance of the diversity of trees in these seasonally inundated forests along the main rivers of the Amazon! 

That's another interesting little tidbit of information! The terrestrial environment has significant impact on the aquatic habitat. And, in this area, aquatic life influences the land!  

That makes sense, right?

Fishes which consume matter found in the substrate (detritivores) and other materials in the substrate (omnivores) also play a fundamental role in the transportation of organic carbon, which is a source of energy for downstream fish communities. Through their foraging activities, these fishes enhance the "downstream transport" and processing of organic material and ensure the proper functioning of the aquatic system and its biological community.

These interdependencies are really complicated- and really interesting!

And it just goes to show you that some of the things we could do in our aquariums (such as utilizing alternative substrate materials, botanicals, and perhaps even submersion-tolerant terrestrial plants) are strongly reminiscent of what happens in the wild. Sure, we typically don't maintain completely "open" systems, but I wonder just how much of the ecology of these fascinating habitats we can replicate in our tanks-and what potential benefits may be realized?

Yes, I think just having a bit more than a superficial understanding of the way botanicals and other materials interact with the aquatic environment, and how we can embrace and replicate these systems in our own aquariums. The real message here is to not be afraid of learning about seemingly complex chemical and biological nuances of blackwater systems.

It can seem a bit  intimidating at first, but if you force yourself beyond just the basic hobby-oriented material out there on these topics (hint: there aren't many!), there is a whole world of stuff you can learn about!

And the information you can gain from this process just might have an amazing impact on your aquarium practice; that might just lead to some remarkable breakthroughs that will forever change the hobby!

And it all starts with looking under those leaves! You never know what you might find!

Stay curious. Stay undaunted. Stay diligent. Stay open-minded...

And Stay Wet.


Scott Fellman

Tannin Aquatics 







December 02, 2018


Mixing it up in the litter bed...following the food- and thriving.

I'm obsessed with leaf litter in the wild and in the aquarium. I think it's because it's literally an oasis of life. Compelling, diverse, and productive.

Many tropical rivers and streams are characterized by large quantities of leaf litter and decaying botanicals on the bottom, with typically clear (but tinted) water. As discussed many times in this column, leaf litter is used as shelter, spawning ground, feeding area, and in some instances, as supplemental food itself. This is a highly productive habitat in nature that also just happens to look really cool in our aquariums, performing exactly the same function!

And fish population density is often correlated with the availability of food resources- and, as we've discussed many times here, leaf litter beds are highly productive food resources! 

In wild habitats, there have been many instances where researchers have counted literally hundreds of fishes per square foot inhabiting the matrix of botanical materials on the bottom of stream beds, which consists primarily of leaf litter.  As dead leaves are broken down by bacterial and fungal action, they develop biofilms and associated populations of microorganisms ("infusoria", etc.) that are an ideal food source for larval fishes.

When you take into account that blackwater environments typically have relatively small populations of planktonic organisms that fish can consume, it makes sense that the productive leaf litter zones are so attractive to fishes!  That being said, leaf litter beds are most amicable to a diversity of life forms These life forms, both planktonic and insect, tend to feed off of the leaf litter itself, as well as fungi and bacteria present in them as they decompose.

The leaf litter bed is a surprisingly dynamic, and one might even say "rich" little benthic biotope, contained within the otherwise "impoverished" waters. And, as we've discussed before on these pages, it should come as no surprise that a large and surprisingly diverse assemblage of fishes make their homes within and closely adjacent to, these litter beds. These are little "food oasis" in areas otherwise relatively devoid of food.

The fishes are not there just to look at the pretty leaves!

Major rivers like the Rio Negro are often called "impoverished" by scientists, in terms of plankton production. They show little seasonal fluctuations in algal and bacterial populations.  This is a fact borne out by many years of study by science. However, "impoverished" doesn't mean "devoid" of life. And in many cases, these populations of food organisms do vary from time to time- and the fish along with them.

Other blackwater systems do show seasonal fluctuations, such as lakes and watercourses enriched with overflow in spring months. At low water levels, the nutrients and population of these life forms are generally more dense.

Creatures like hydracarines (mites), insects, like chironomids (hello, blood worms!), and copepods, like Daphnia, are the dominant fauna that fishes tend to feed on in these waters.  This is interesting to contemplate when we consider what to feed our fishes in aquariums, isn't it? 

There's a lot of food out there, for the fishes willing to look for it...which, pretty much all of them devote most of their lives to doing, lol

It's not really that much different in the aquarium, is it? I mean, as the leaves and botanicals break down, they are acted upon by fungi and bacteria, the degree of which is dependent upon the available food sources. Granted, with fishes in a closer proximity and higher density than in many wild systems, the natural food sources are not sufficient to be the primary source of food for our fishes- but they are one hell of a supplement, right?

That's why, in a botanical-rich, leaf litter dominated aquarium, you see the fishes spending a lot of time foraging in and among the litter...just like in nature. 

There is something oddly compelling to us when we look at both aquariums and natural biotopes with a diverse, interesting botanical structure. You set the stage with wood, plants, and then enhance it even more with botanical materials. 

Nature does the rest. 

The fishes will follow.

Stay engaged. Stay excited. Stay focused. Stay patient...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

November 30, 2018


Why I hate Cory Hopkins. (Or, not being able to see the forest for the trees...)

You know how it goes in our hobby.

We get into some obscure interest. We develop technique and approaches and ideas to execute.

And sometimes, in our zest to just "do"- we overlook the entirely obvious. Someone comes along with an idea that sort of throws us into a spin!

Enter Cory Hopkins.

I hate him.

I hate him because not only is the guy one of the top aquascapers in the world- he's a botanical-style aquarium savant, and an innovator! Cory has executed some of the most exciting and compelling BWBS aquascapes we've ever seen, helped us source some of our most popular botanicals, and experimented with all sorts of ways to play with said botanicals in unique ways in aquariums.

So, why do I hate the guy? Really?

Let me explain.

Well, I think I hate him because he figured out a great way to do something that we just take for granted...Yeah, he made the first great innovation to the art of botanical preparation.

The process of prepping leaves, as I tend to execute it, has been to boil or steep them for anywhere between 10-20 minutes. It's not a difficult process, but it takes a bit of time and effort to do this.

So what does Cory, the self-professed "lazy" guy- the world-class 'scaper; the "sourcer" and tinkerer of cool botanicals, do? 

He develops a freakin' "hack."

He throws the damn leaves in a Pyrex bowl, hits "5 minutes" or whatever, walks away, and boils the damn microwave...


Yeah. A hack. A shortcut. A very, very cool idea. Simple. Effective. Shockingly innovative.


Why didn't I think of this?


It's so obvious. So simple. So...

And it works. Of course.

I know this 'cause, yeah- I tried it myself, damn it. At 10:00PM.

Now, I haven't tried this with pods...but I can't see why it wouldn't work...just needs longer periods of time, right? If a microwave could expedite the process, then...


Cory- I hate you. I hate you because I can't believe I haven't thought of this idea myself already.

So to you, Cory my friend. Keep creating great 'scapes. Keep blowing our minds with your botanical ideas...Keep being "lazy."

You just might change the world...Well, our world, anyways.

In the mean time, I will keep hating you- but in the nicest, most respectful way possible! 😆

Stay bold. Stay innovative. Stay curious. Stay diligent...

And Stay Wet.


Scott Fellman

Tannin Aquatics.


November 29, 2018


The "Asian Transformation..." Already underway. Already exciting.

The world of tropical fishes is as broad and diverse as the environments from which they come- and few regions offer as much diversity in this respect as Asia. The sheer number of habitats and the fishes which live in them in Asia is staggering. And so many of them are blackwater or otherwise "botanically-influenced" habitats that the opportunities for us to experiment with them in our aquariums is almost limitless!

From a standpoint of fishes, Asian species have never been more available in the trade, nor the selection more diverse. With many being captive-bred, the opportunity for us to try species that were previously obscure or otherwise under-appreciated in the hobby is easier than ever before!

I credit some of this to the exploding popularity of planted aquariums, which has resulted in more interest in small, "plant-compatible" species. And with more interest in different fish and plant species comes more interest in replicating some of the wild habitats from which they come!

And, oh, yeah- planted blackwater aquariums are an exploding area of interest within our botanical-influenced world! There are numerous species which do very, very well under these types of conditions- so much to be done here! Yes, the Asian blackwater habitats often contain terrific plants, like various Cryptocoryne, Bucephelandra, etc. And many of these plants do better in aquarium designed to meet their requirements.

PREDICTION FOR 2019: I think we will see a lot more interesting setups featuring plants and mixes of plants and other elements as more and more aquarists play in this area. And with more experimentation will come more understanding of the plants that come from other blackwater habitats around the world.

We've seen a big surge in the popularity of wild Betta species and lesser-known Gouramis. Having the experience in playing with Tetras and other South American blackwater fishes has given ideas and let's face it- a confidence boost- to many hobbyists who have been keeping the compelling Asian fishes for years, and were looking for something a bit different for them.

The same mindset that we've been applying to South American fishes: The mindset that makes us say to ourselves, "What if I keep this fish in an environment similar to the one where they come from I the wild?" (okay, well- I say that to myself!)

This is interesting and exciting.

Some forgotten favorites, like Barbs, are starting to see an uptick in popularity again. And what better way for us to appreciate their fantastic colors and behaviors than to provide them aquarium conditions similar to what they evolved in?

I  think we'll see some very interesting developments in breeding some of these fishes. Now, Im not saying that no one has ever bred Snakeskin Barbs or Tiger Barbs. What I am saying is that we generally have no problem keeping and breeding them under "typical" aquarium conditions- but that we'll potentially have far more interesting results with them when we maintain them under the conditions that we provide in blackwater, botanical-style aquariums. 

Some of the Barbs that where perhaps less appreciated and (how do we say it nicely) "more subtly colored" when kept under harder, more alkaline conditions will show substantially more attractive coloration when they are exposed to the manifold benefits which a BSBW aquarium can provide!

And of course, the health, appearance, and breeding possibilities for the fishes we collectively refer to as Rasbora have long benefitted from the use of leaves and other botanical materials in their aquariums. Only now, we have a more "focused" ability and desire to provide them with natural conditions in our aquaria. And of course, the opportunity to replicate many of the unique environments from which these fishes come, along with...aquatic, yeah. Who wouldn't be excited about this stuff?

Ohh, and what about the implications for keeping some of the oldest of the "old school" fishes- and among the most under-appreciated- the Gouramis? Think of the incredible potential here...Many of these fishes come from habitats which are not only fascinating- they're vanishing. Endangered by environmental changes, man's encroachment into them, and other artificial pressures. Learning about these habitats, and attempting to replicate their form and function in the aquarium may prove to be critical to the long-term survival of many species in both the wild and the aquarium.

(The call of the Gouramis is real! Pic by Luke Bescoby)

PREDICTION FOR 2019:. This could be the dawn of a new era for the Gouramis! These "staples" of the aquarium trade will be seen in a new and better light...appreciated as much for their interesting habits and fantastic colors as they are for the way they can thrive under BWBS aquarium conditions.

And of course, the always-popular dwarf shrimp have long benefitted from botanical-style aquarium conditions. It's something that's been known for a long time, but being able to tie it together with what we do simply opens up more and more opportunities for success.

And then there are the Loaches. 

Who hasn't kept an entertaining and attractive Loach or two over the years?

Yeah, such a diverse and fascinating group of fishes. Many, many species are already in the hobby. New species are being described (and re-described, in some cases) on a regular basis, and are popular fishes already, of course. However, with more of an emphasis on providing them with more naturalistic (both functionally AND aesthetically) conditions in the aquarium, you open up numerous possibilities for breakthroughs in their husbandry and breeding. 

I know, it's a theme we are seeing again and again. However, it's quite an exciting one, filled with opportunities for almost any hobbyist who's willing to do a little research and devote some time and effort; to be a part of the building potential breakthroughs on yet another group of fishes which have "just sort of been there" in the hobby for decades.

PREDICTION FOR 2109: A growing interest in Loaches in botanical-style aquariums. 

I can go on and on and on with "predictions"- many of which are just as likely to be "hopes" as to what I'd like to see, lol.  The "transformation", if you will of the way we look at Asian-themed aquariums is already underway, but the interest and excitement in our community is growing daily. That being said, I can promise that we at Tannin Aquatics will do our part to pump out some inspiring and hopefully- motivating- Asian-aquarium-themed content which will encourage experimentation!

And we'll be releasing more and more interesting botanicals, hard goods, and other aquascaping materials in the coming weeks that will enable you to create some compelling and interesting aquatic displays! Stay tuned!  Add these to the many Asian-origin botanical materials we already offer, and you'll have a real "arsenal" of natural materials to create a compelling Asian-themed aquascape/environment for your fishes!

Yes, it's literally a whole new world to explore! One filled with exciting possibilities for aesthetics, husbandry breakthroughs, and increased knowledge of the (often threatened) wild environments and fishes of Asia. 

Who's in? Who's ALREADY in? 😆

Stay excited. Stay curious. Stay creative. Stay engaged...

And Stay Wet.


Scott Fellman

Tannin Aquatics



November 28, 2018


World in a box.

It's fun to see how the paradigms have shifted in the aquarium hobby over the past few years, particularly when it comes to our embrace of more natural, blackwater/botanical-style aquariums.

We've gone from tentatively keeping fishes in aquariums that more carefully embrace some natural conditions they evolved under, to full-blown replications of their environments, tinted water, decomposition, and all.

We've begun to understand that it's not all about creating the most scrupulously clean environment possible for the animals under our care- it's about maintaining the best possible dynamic for their overall health, growth, longevity, and hopefully- reproduction. Creating and fostering processes and conditions that create a biological balance within our little (or not so little) glass and acrylic boxes we call "aquariums."

I've seen this a lot in the "reef" side of the hobby: Within the past 10 years in the reef hobby, we've went from a doctrine of "You should have undectable nitrates and phosphates in your reef aquarium because natural reefs are virtual nutrient deserts!" to "You need to have a balance between too much and too little."

We've come to understand that reef aquariums- like any type of aquarium- are biological "microcosms", which encompass a vast array of life forms, including not just fishes, corals, and invertebrates, but macro algae, benthic animals (like worms, copepods, and amphipods), planktonic life, and more.

Reefers came to understand- as freshwater pioneers did generations before- that just because a reef has undetectable phosphates and nitrates in the waters surrounding it, our aquariums don't have to run that way. Corals need nutrients and food, and an aquarium is not a natural reef; an open system with uncounted millions of gallons of water passing through it hourly.

And they change and evolve on a continuous basis. 

I used to feel that the whole idea of keeping an aquarium was to keep it pristine and untouched, like the day it was set up...sort of like a new know...don't get that first scratch on it! Like, I was afraid to do stuff  in my tanks that would stir up the sand or to move stuff around too much. Disrupt the system to the point of no return.

I was worried it would stress the fishes too much, or whatever. As if nature isn't filled with all sorts of natural occurrences which our fishes need to compensate for in some manner? Now, I realize that in nature, a fish can escape pretty far away from a disturbance, but still..a disturbance is a disturbance, right? And fishes survive all sorts of "disturbances", right?


The "earthy, organic and natural" vibe that we talk about so much here seems to be catchy! Unlike some of the more "sterile", rigidly-styled variations of "natural" aquariums that have been embraced by many for so long, this "style" of aquarium really seems to lend itself to a far more "realistic" presentation in the eyes of many, and provides the freedom of expression that only nature can provide.


Seeing the wonderful pics of wild blackwater habitats being shared by our friends has created a powerful and compelling message for many that these aquariums are some of the more accurate depictions of natural aquatic habitats than many had previously realized.

Unique. Vibrant. Brimming with life.

We've started to make the effort to really understand the differences- and similarities-between the natural environment and the little worlds we create in our own horns for our fishes. We're starting to blur the lines between nature and aquarium in ways not previously considered or thought about. 

A melding of the look and function of nature in our aquairums.

"Functional aesthetics."

And it starts by understanding how aquatic environments function in nature and in our aquairums.

With biotope and theme aquariums quite the rage, we've come to really appreciate the acceptance of this mind set...that an aquarium is a microcosm- a functioning little biological community, with a full compliment of life forms. Yes, I know, it's not new...Just something that was, IMHO, forgotten- perhaps tucked under the rug for a bit as we pursued different avenues within the hobby...

However, it's coming back. 


What many fish breeders knew for so long- that blackwater conditions created by tannins and humic substances can lead to healthier fishes and more prolific, viable spawns- is being experienced and shared by more "casual" hobbyists, which will have great long-term implications for sustainability of the animals we cherish. Maintaining these types of conditions "full-time"- not just when we want to spawn our fishes- is a big step.

An evolution of sorts.

It is important to understand that all natural bodies of water contain humic substances. From Ocean water, to the Mississippi river, to the Amazon River, to ice covered lakes in Antartica. This should be a lesson to everyone. Life has a way of producing what is needed to prolong life. If humic substances are found in lakes covered by hundreds of feet of ice in Antarctica, there is a reason they are there. It's because they are a foundational necessity.

In some environments, such as our beloved blackwater environments, they make life possible-allowing fishes to survive in very low pH conditions. Fish could not exist in these conditions without them. In other environments, such as Central American aquifer-fed streams, or African Rift Lakes, they make life better.

This is perhaps best stated in a March 2008 Study conducted by Humboldt University at Berlin, Institute of Biology, Freshwater and Stress Ecology, Germany, in which they came to the conclusion that, “It appears that dissolved HS have to be considered abiotic ecological driving forces, somewhat less obvious than temperature, nutrients, or light.”

The body of scientific evidence to support the manifold benefits of these compounds is compelling enough for us to make a strong conclusion:

Humic substances, once considered a "fringe" aspect of the aquarium hobby- products previously employed only by blackwater enthusiasts- should instead be considered an essential component of every aquarium, almost as important as temperature and food.

So, yeah, utilizing leaves, wood, and botanicals in all sorts of aquariums is not only beneficial, it helps in many ways to replicate the physio-chemical conditions under which fishes are found. 

Sure, there is so much we need to learn. So much to experiment with. However, we're finding out ways to apply what we do in our botanical aquarium world to a variety of hobby practices. 

Like planted aquairums. 

The area of planted blackwater aquariums is really starting to take off! And it's understandable: Lots of plants come from, and can do very well in blackwater habitats! And we're finding out all sorts of ways to utilize aquatic plants in blackwater aquariums-something which is going to have broad implication for the planted aquarium hobby. Something that has crossover potential for all sorts of aquarium work!

As we've said so many times before, the idea of blackwater/botanical-style aquariums is not just about a cool aesthetic. It's about understanding and embracing natural processes, and appreciating the many benefits they provide for the fishes we treasure so much.

It's about creating and managing a world in a box.

Make your contribution to the evolving art and science of blackwater, botanical-style aquariums. Everyone can make a difference. Everyone can break new ground in this exciting hobby specialty.

Stay involved. Stay excited. Stay experimental. Stay bold. Stay open-minded...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

November 27, 2018


Elevating the bottom...Another look at the evolving art and science of "substrate enrichment"

Okay, that was a weird title, huh? Almost sounds a bit obscene;'s not what you think!

I'm really into aquarium substrates.

LIke, obsessively so.

Specifically, creating substrates that are a reasonable representation of the bottom of habitats as diverse and unique as streams, ponds, temporal pools, peat bogs, and igarapes, as found in the tropical regions of the world. Each one of these habitats has some unique characteristics, and each one presents an interesting creative challenge for the intrepid hobbyist. Until quite recently, the most common materials we had to work with when attempting to replicate these substrates were sand, natural and colored gravels, and clay-comprised planted aquarium substrates.

And, since, as mentioned above, I'm a bit obsessed with substrates, that's why we offer a variety of other materials into your botanical-style aquarium substrate! 

If you're truly adventurous, this opens up a lot of cool possibilities for interesting functional and beautiful tanks. The bottom itself becomes a big part of the aesthetic focus of the aquarium, with the botanicals mixed into, or becoming the substrate- the world opens up!

These materials form an attractive, texturally varied "microscape" of their own, creating color, biodiversity, and interest. In fact, I dare say that one of the next frontiers in our niche would be an aquarium which is just substrate materials, without any "vertical relief" provide by wood or rocks.

Well, that's just me, of course... 🤓

Scientists have identified a number of different soil classes throughout the world. In the Amazonian region, a type of soil known as "Podzol" is associated with with black water rivers and lakes. "Podzols" are soils characterized by a whitish-grey subsurface, bleached by organic acids. They have an overlying dark accumulation of brown or black illuviated humus.These soils support the rainforests surrounding blackwater streams, yet are the most infertile soils in Amazonia. Now, this makes a certain degree of sense, right, because we've long been told how "nutrient poor" blackwater systems are, and it starts with the substrate, right?

Even though it's nothing like the super fertile "garden forests" we imagine, there is a lot of terrestrial vegetation over this soil.  Locally called Varrillal which translates to “land of twigs”, it's a "stunted" forest, comprised of abundant thin, relatively short trees. A significant "root mat" covers the soils, and it's thought that most of the nutrient exchange must occur in this root mat, which keeps the remaining nutrients held within the system- hence the low nutrient levels. And it's another explanation for the relatively nutrient poor water in blackwater systems, right? The terrestrial plants are "hogging" all of the good stuff! (what little of it there is, anyways)

And then there are the aesthetics...

If you've seen pictures and videos taken underwater in tropical streams (again, I'm pulling heavily from the Amazonian region), you'll note that there is a lot of loose, soil-like material over a harder mud/sand substrate. Obviously, using an entirely mud-based substrate in an aquarium, although technically possible- will result in a yucky mess whenever you disturb the material during routine maintenance and other tasks. You'd need to "cap" it with more substantial materials to hold it in place. Anyone who's done a "mudded substrate" planted aquarium knows this!

So, how does the "tinter" create a more interesting, functionally aesthetic substrate in the aquarium?

Well, you could start with a thin layer of aquarium-grade sand, and build from there. I am a big fan of some of the finer sand materials, such as CaribSea's "Sunset Gold." This substrate , IMHO, faithfully represents (in appearanc,e) the podzol-comprised materials found in Amazonian regions. 

You could mix in stuff like our "Fundo Tropical", a course coconut-based material, or its counterpart, "Substrato Fino" (a very fine-grained version). These materials  have the added advantage of staying "down" nicely once you prepare them for use (boiling is the preferred method). They also last a very long time, becoming essentially inert after they releases their initial tannins into the water column. The intricate "matrix" it forms will become a very useful foraging area for many fishes, hosting small benthic life forms, just like natural stream bottoms do.

To this milieu, you could add materials like our "Mixed Leaf Media", a mix of several types of crushed tropical leaves, or "bits and pieces" of stuff like catappa bark, oak twigs, etc. These have that "functional aesthetic" benefit of looking very natural, while simultaneously imparting tannins and supporting the aforementioned life forms.

That's a lot of decomposing stuff, huh?

"Hey, Scott. Your proposing that I add a shitload of stuff that may trap detritus, uneaten food, solid fish waste, etc.- and some of it will break down in the process! Sounds like a recipe for a lot of debris in the system!" 

(Oh, just say it- you wanted to tell me it's a maintenance liability and sort of a mess if you're not meticulous and diligent in maintaining it). It's important to have adequate water movement, creation, and overall good husbandry when attempting such a substrate.

Well, yeah.

This kind of combination of natural materials can create a potentially messy substrate area if you are not a careful feeder, over-stock your aquarium, and tend to let things go. So, just be conscientious about maintenance!

That being said, I've found that, much like in nature, the materials that we place on the bottom of the aquarium will become an active, integral part of the ecosystem. From a "functional" standpoint, bottoms comprised entirely of, or supplemented with a variety of botanical materials form a sort of "in-tank refugium", which allows small aquatic crustaceans, fungi, and other microorganisms to multiply and provide supplemental food for the aquarium, as we've touched on before.

Stability and ease of maintenance are the (surprising?) benefits of such an enriched substrate, in my experience! 

It's certainly no stretch to call our use of botanicals as a form of "active substrate", much like the use of clays, mineral additives, soils, etc. in planted aquariums. Although our emphasis is on creating specific water conditions, fostering the growth of microorganisms and fungi, as well as creating unique aesthetics, versus the "more traditional" substrate materials fostering conditions specifically for plant growth.

About the most I could hope for in a quick piece like this is to pique your interest in taking a fresh look at the substrates that we typically give little to no "play."

I hope I've done that!

Let's see some experiments. Let's see some cool-looking 'scapes which aesthetically AND functionally represent the unique tropical substrates which form a highly important part of the fascinating ecosystems we love so much!

Stay innovative. Stay dedicated. Stay curious. Stay excited. Stay diligent...

And Stay Wet.


Scott Fellman

Tannin Aquatics 



November 26, 2018


A detour on the way to "benign neglect?" Or just a validation...?

Like most of you, I'm a borderline obsessive aquarist...Like, I constantly observe, test, tweak each and every tank, every day. That being said, I have learned over the years that a well thought-out aquarium doesn't need endless doting attention on a non-stop basis. In fact, because of a busy travel schedule, "company building", and just life in general over the last few years, I even might have missed a water exchange or feeding or two..or three...or...

Yeah, I'm not proud of it- but I won't deny it, either. In my world, missing water exchanges and feedings and such were, for many years, a sort of "scarlet letter" that you ended up wearing for all to see (well, even if no one else just felt, I dunno...guilty!).

Now, I always hung around reefing friends who were obsessed with- even proud of- their "ability" to run a "successful" system without water exchanges and such. They'd actually use a sort of "reverse mentality", in which you'd hear them proudly brag about stuff like, "I never run a protein skimmer on my reef." Or, "I haven't done a water change in like a year!"  I mean, that was stuff that would make my head spin... I was like, "If you're gonna be a loser aquarist- don't brag about it!"

I take a dim view of some stuff (shocker, I know...)!

Yeah, I was/am all about continuous, regular maintenance and dedicated husbandry practices-particularly water exchanges, for which there is simply no substitute for, or no valid reason NOT to execute, IMHO. However, there is one "basic" aspect of aquarium keeping that I have always employed a bit of an "intentional avoidance" of:


"WTF, Fellman. Skip a goddam water change...But feeding? Really?"

Yes. Really.

But before you flame me for being hypocritical or lazy, or even guilty of "benign neglect"- hear me out. It's not really about being lazy. It's an intentional thing. I plan for it. In fact, you do too, even though you may not think about it.

Of all of the things we do in our blackwater/botanical-style aquariums, one of the few "basic practices" that I think we can actually allow nature to do some of the work on is to provide some sustenance for our fishes.

Think about it: We load up our systems with large quantities of leaves and botanicals, which serve as direct food for some species, such as shrimp and perhaps Barbs and Loaches.

These materials famously recruit biofilm and fungal growths, which we have discussed ad nasueum here over the years. These are nutritious, natural food sources for most fishes and invertebrates. And of course, there are the associated microorganisms which feed on the decomposing botanicals and leaves and their resulting detritus.

Now, we have briefly talked about how decomposing leaf litter does support population of infusoria- a collective term used to describe minute aquatic creatures such as ciliates, euglenoids, protozoa, unicellular algae and small invertebrates that exist in freshwater ecosystems. Yet, there is much to explore on this topic. It's no secret, or surprise- to most aquarists who've played with botanicals, that a tank with a healthy leaf litter component is a pretty good place for the rearing of fry of species associated with blackwater environments!

It's been observed by many aquarists, particularly those who breed loricariids, that the fry have significantly higher survival rates when reared in systems with leaves present. I'm sure some success of this could be attributed to the population of infusoria, etc. present within the system as the leaves break down. Biofilms, as we've discussed many times before, contain a complex mix of sugars, bacteria, and other materials, all of which are relatively nutritious for animals which feed on them.

It therefore would make a lot of sense that a botanical-influenced aquarium with a respectable growth of biofilm would be a great place to rear fry! Maybe not the most attractive place, from an aesthetic standpoint- but a system where the little guys are essentially "knee deep" in supplemental natural food at any given time is a beautiful thing to the busy fish breeder!

And yeah, my experience indicates it performs a similar role for adults.

In the wild, creatures like hydracarines (mites), insects, like chironomids (hello, blood worms!), and copepods, like Daphnia, are the dominant fauna that fishes tend to feed on in these waters.  This is interesting to contemplate when we consider what to feed our fishes in aquariums, isn't it?

Anyways, these life forms, both planktonic and insect, tend to feed off of the leaf litter itself, as well as fungi and bacteria present in them as they decompose. The leaf litter bed is a surprisingly dynamic, and one might even say "rich" little benthic biotope, contained within the otherwise "impoverished" waters.

And, as we've discussed before on these pages, it should come as no surprise that a large and surprisingly diverse assemblage of fishes make their homes within and closely adjacent to, these litter beds. These are little "food oases" in areas otherwise relatively devoid of food. The fishes are not there just to look at the pretty leaves!

And of course, it goes without saying that nature works in the aquarium (if allowed to do so) in a similar manner in the aquarium. The leaves and botanicals we add to our tanks do what they've done in nature for eons: They support the basis for a surprisingly rich and diverse "food web", which enables many of the resident life forms- from bacteria, to insects...right up to our fishes- to derive some, if not all of their sustenance from this milieu.

Confession time?


I've created botanical tanks for years with part of the intention being to see if I can support the resident fishes with minimal external food inputs. My rationale was that, not only will the leaves and botanicals foster such food webs as they do in nature, but that the lower amount of external food inputs by the aquarist helps foster a cleaner system, which is especially important when one takes into account the large amount of bioload decomposing leaves and botanicals account for in the aquarium!

And guess what? It works. Just fine.

A beautiful case in point is my latest little office aquarium; that little "nano" tank which is 'scaped only with Texas Live Oak Leaves, Yellow Mangrove Leaves, and Oak Twigs.

Now I know this tank isn't everyone's idea of aesthetic perfection..I mean, it's essentially a pile of leaves...However, to the fishes and other life forms which reside in the tank, it's their world; their food source.

I maintain a shoal of 25 "Green Neon Tetras", Parachierdon simulans, in this tank. This tank has been up and running about three months without a single external food input since the fish have been in the tank. They are subsisting entirely on the epiphytic matter and microorganisms found in the leaves...Nothing else.

And they are as active, fat, and happy as any Green Neons I've veer seen.

In fact, they've almost doubled in size since I obtained them. Some of the fishes were shockingly emaciated and weak upon arrival, were rehabilitated somewhat in quarantine, but weren't 100% when released into the display (yeah, I know- NOT a "best practice", but intentional for this experiment). At this point, I can't tell them apart from the rest of their tankmates!

Now sure, this is a relatively small population of little fishes in a small tank. The environment itself is carefully monitored. Regular water exchanges and testing are employed. All of the "usual stuff" we do in an aquarium...except feeding.

Of course, I don't think that such a success could be replicated with fishes like cichlids or other larger, more predatory type fishes, unless you utilized a large aquarium with a significant "pre-stocked" population of crustaceans, insects, and maybe even (gulp) "feeder-type" fishes. I mean, you could do this...

However, it is really a more successful approach with fishes like characins, Rasbora, Danios, some catfishes, Loaches, etc.

So yeah, this practice is entirely replicable, and can be successful with many fishes. It's a bit "contrarian" to standard aquarium practice, I suppose, to some extent. However, it's not all that "radical" a concept, right? I mean, it's essentially allowing Nature to do what she does best- cultivate an ecosystem...which she will do, if given the "impetus" and left to her own devices. 

It's not really "benign neglect." It's the facilitating of a process which has been going on for eons...a validation of what we experiment with on a daily basis in our "tinted" world.

We invite you to experiment for yourself with this fascinating and compelling topic!

Stay curious. Stay diligent. Stay patient. Stay skeptical. Stay proud...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

November 25, 2018


How many leaves does it take..? Hint? We're $#@&ing clueless...

What a cheerful, confidence-building title, huh?

Well, it's honest, at least!

I suppose one of the most commonly asked questions I get here is, "How many ________ does it take to tint my water?"

And my most common response?

"I have no idea!"

Pretty much NOT the response that you'd expect from someone who curates, obsesses over, and sells leaves for a living, I know. But here's the thing: There are a ton of variables, such as the composition of your water, the size of the aquarium, water movement, where you incorporate them in your system (i.e., in a filter chamber, canister, reactor, or the display itself), and wether or not you utilize some form of chemical filtration (such as activated carbon, etc.), and exactly WHAT your goal is for using them in your aquarium, just to name a few.

Leaves are really tricky little bastards, when it comes to "how many?"

I can tell you, as a sweeping generality, that it typically takes me at least 2-4 ounces of Texas Live Oak leaves, Yellow Mangrove Leaves, or a dozen or more Guava and Jackfruit Leaves to get a decent level of "tint" in an aquarium of say 30-50 U.S. gallons, when simply placed in the tank. Catappa leaves? Well, it typically takes about 10-12 medium-sized ones to do the job in my tank. 

Guava, Jackfruit, and some other leaves tend to impart a less significant tint to the water in my experience- an almost yellowish-gold color, so you can use more of them, especially in conjunction with Catappa, to achieve a great affect!

And the pH thing?

Now, I"m starting with RO/DI water with essentially no carbonate hardness and a very "flexible" pH. Not only do the botanicals influence the color, but they can influence the pH under these circumstances. Simply adding catappa or other leaves to your hard, alkaline tap water will have little to no effect, other than to impart some color and maybe increase your TDS a bit.

However, the tannins, which are the substances which tint the water, cannot "overcome" the Calcium and Magnesium ions, and drive down the pH significantly in water with high levels of these carbonate hardness present. It simply is putting more materials into the water (which are often detectible by TDS meters in aquariums).

Remember, there are multiple factors in play, and multiple goals you might have for adding leaves to your tank. If it's just about the aesthetics of having leaves in the tank, and you want clear water, use activated carbon in your filter and call it a day! If you're all about a deeply tinted and low pH environment, you need to eliminate activated carbon in large quantities, employ RO/DI water, and likely use quite a bit more of these materials than I am talking about here.

You have to experiment. There is simply no "recipe" out there that can give you "Instant Amazon" conditions by adding "a little of this and a bit of that" to your tank, despite what "experts" or vendors will tell you. There just isn't. Period. 

I could talk until "the cows come home" about how much of this and that I use in my tank- but I may have a combination of factors that are vastly different from the environment in your aquarium. Sure, you can get a general idea- but your results will vary. Every tank is different. I think it's more about understanding the general "practices" involved versus how many of whatever to add.

In my display tank in my home, I use a rlot of Yellow Mangrove and Texas Live Oak, with a bunch of Borneo Catappa Bark and Oak twigs to achieve a nice color that I like. I also have a pH of around 6.6 and undetectable carbonate hardness; a TDS of around 10 (interesting....). Oh, and I use a hardscape comprised of "Spider Wood", which, especially when "fresh", imparts hella tint to your water! I'd almost call the use of wood a "hack" when it comes to visual tinting of water...

But that's me.

Back to the subject of chemical filtration in blackwater tanks for a bit...

Now, I've already touched on the issue of chemical filtration and its impact on removing the tint and tannins associated with leaves and botanicals. It's entirely possible to minimize or render the ph-lowering and water-tinting capability of tannins released by leaves with activated carbon, Purigen, or other chemical filtration media. Tannins are rather weak acids, yet they can lower the pH of water when their is less "buffer" in the system (i.e.; lower general hardness). Just how much tannins can lower pH in a given system depends upon how much buffering capacity the water has. 

With "harder" water (i.e., water with a greater buffering capacity), you can have the tinted water look from leaves and wood, without the pH reducing effects, particularly if the tannic acids are absorbed by the aforementioned chemical filtration media. So, in other words, you can have the aesthetics of blackwater while running your aquarium at a higher pH if the hardness is sufficient. Once you remove tannins in a lower hardness system, your pH should rise, too, since you're removing the acids.

Woah. Head spin time. 

Bottom line is this: You can use chemical filtration media in "tinted" tanks. However, depending upon the amount of media, quantity of tannin-producing items (leaves, wood, botanicals, etc.) and the capacity of the aquarium, the impact will be variable. I run chemical filtration media (Purigen and activated carbon) in my tanks, and I still have nice tint and pH relatively stable, as mentioned above. It's a fine line between "too much" and "too little", and you will simply have to experiment to find what works best for you!

And more water chem talk?

Again, I attribute my relatively stable soft, mildly acidic conditions to the use of reverse osmosis/deionization (RO/DI) to pre-treat my tap water. RO/DI units are a bit pricy at first, but IMHO, they are an essential piece of a equipment and a very wise investment for the aspiring BWBS hobbyist!

Remember-  Botanicals and leaves will NOT soften your water. It's perhaps the most misunderstood thing of all about botanicals? Maybe. I think it's easy to see how this one got started and tends to hang around a bit. Most botanical materials contain tannins and humic substances, which can drive down the pH in water with little to no carbonate hardness.  And of course, the tinted, soft acidic water in many natural habitats often has an abundance of leaves and botanicals present. I think that this gave a lot of hobbyists the impression that you could simply add some of these materials (leaves, etc.) into your tap water and create "Rio Negro-like" conditions easily!

This can only be accomplished with reverse osmosis or ion exchange( a process in which calcium and magnesium ions are "exchanged" for sodium or potassium ions.)

Reverse osmosis is a water treatment process which relies on a membrane which has pores large enough to admit water molecules, yet "hardness ions" such as Ca2+ and Mg2+ remain behind and are flushed away by excess water. The resulting product water is thus called "soft water"-free of hardness ions without any other ions being added. 

Get an RO/DI unto and be done with it...

And it is now widely accepted by science that humic substances (such as those present in botanicals) are thought to have a wide range of health benefits for fishes in all types of habitats. We've covered this before in a great guest blog by Vince Dollar, and the implications for the hobby and industry are profound. Although they are not the "cure all" that many vendors have touted them as, leaves and other botanicals do possess a wide range of substances which can have significantly beneficial impact on fish health.

How often do you need to replace your leaves and botanicals  Well, another great question for  which there is no "rule" involved. The reality is that you can simply add new leaves on a regular basis, so you'll always be making up for the ones that have decomposed. Some hobbyists like to remove the decomposed leaves, preferring a more "pristine" look.

It boils down to aesthetics, really.

This tinted world we play in, with its cool aesthetics, confounding chemistry, and abundance of assumptions and "aquarium hobby urban myths" is really something, isn't it? You just read almost 2,000 words telling you that there is no single way to achieve your goal...not exactly earth-shattering, but entirely symbolic of this fascinating world were in!

Be bold and experiment...find your path to tinted Nirvana!

Stay curious. Stay diligent. Stay engaged. Stay skeptical. Stay excited. Stay open-minded...

And Stay Wet.


Scott Fellman

Tannin Aquatics