Is it in the water?

As you know, by now, when I get on a "roll" about something, I tend not to let up on it, right? I've been bothering you a lot about the idea of "functional aesthetics" in the natural-style botanical aquarium. In other words, creating an aquascape in your tank comprised of natural materials assembled in such a way as to not only be aesthetically pleasing, but to enhance the aquatic environment chemically, biologically, or physically. 

And interestingly, I tend to stumble on stuff that reinforces this idea on a pretty regular basis. I think it's largely because I'm attuned to these kinds of "fun facts" and when I see stuff that reinforces the concept, I'll often jump right into it. 

Such a case occurred the other day when I was visiting a killifish forum on Facebook. One of the participants was discussing some new fishes he obtained, and one was from a rare genus called Episemion. Weird, because it is a fish that falls genetically halfway between Epiplatys and Aphyosemion.

Even more interesting to me was the discussion that it's notoriously difficult to spawn, and that it is only found in a couple of places in The Congo.

And even more interesting was that it is in a region known for high levels of selenium I the soil...And that's VERY interesting. Selenium is known to be nutritionally beneficial to animals and humans at a concentration of 0.05-0.10ppm. It's an essential component of many enzymes and proteins, and deficiencies are known to cause diseases. One of it's known health benefits for animal is that it plays a key role in immune and reproductive functions!

Okay, that helps with the "difficult to breed" part, right?

Selenium occurs in soil associated with sulfide minerals. It's found in plants at varying concentrations which are dictated by the pH, moisture content, and other factors. Soils which contain high concentration of selenium are found in greater concentration in plants which occur in these regions. 


So, I"m doubtful that we know the specific concentrations of selenium in many of the planted aquarium substrates out on the market, and most hobbyists aren't just throwing in that "readily available" tropical Congo soil that you can pick up at any LFS in their tanks, right? 😜

So, how would we get more selenium into our tanks for our killies?

Botanicals could be one way. Like, The Brazil nut...


And the Brazil nut is kind of known to us, isn't it? The Monkey Pot has something to do with tis, right?

And, yes-  it's technically a fruit capsule, produced from the abundant tree, Lecythis pisonis, native to South America -most notably, the Amazonian region. Astute, particularly geeky readers of "The Tint" will recognize the name as a derivative of the family  Lecythidaceae, which just happens to be the family in which the genus Cariniana is know, the "Cariniana Pod." Yeah...this family has a number of botanical-producing trees in it, right?


Hmm...Lecythidae...'s also known as the taxonomic family which contains the genus Bertholletia- the genus which contains the tree, Bertholletia excelsa- the bearer of the "Brazil Nut." You know, the one that comes in the can of "mixed nuts" that no one really likes? The one that, if you buy it in the shell, you need a  freakin' sledge hammer to crack?

Yeah. That one.


Craving more useless Brazil Nut trivia?

Check this out: Because of their larger size size, they tend to rise to the top of the can of mixed nuts from vibrations which are encountered during transport...this is a textbook example of the physics concept of granular convectionwhich for this reason is frequently called...wait for it...the "Brazil Nut effect." (I am totally serious!)

Okay, anyways...woudl it be possible to somehow utilize the "Monkey Pot" in a tank with these fishes to perhaps impart some additional selenium into the water? Okay, this begs additional questions? How much? How rapidly? In what form? Wouldn't it be easier to just grind up some Brazil nuts and toss 'em in? Or would the fruit capsule itself have a greater concentration of selenium? Would it even leach into the water?

Where the ---- am I going with this exercise?

I'm just sort of taking you out on the ledge here; demonstrating how the idea of utilizing botanicals to provide "functional aesthetics" is, at the every least, a possibility to help solve some potential challenges in the hobby. 

Like, this is something that we have done with Catappa leaves forever. You've seen my numerous reviews on them and the alleged health benefits that they are purported to offer fishes. Some is marketing bullshit. Some of it IS legit...SO, could the same assumption be made for botanicals?

I think so. I think it's worth investigating; experimenting...right?

We offer a lot of botanicals here at Tannin Aquatics, many of which find their way into tropical aquatic habitats around the world. Many come from regions where specific soil types are found...perhaps they contain concentrations of various micronutrients or minerals which are beneficial to fishes in ways that haven't been thoroughly studied..or at least, the connection between the two hasn't. 

We often hear from our customers how fishes seem to spawn not long after botanicals are introduced toothier tank, or how they are seemingly healthier and more colorful, etc. Is it just the tannins? The humic substances? Or other compounds found in the botanicals? 

A ton to learn here. The possibilities are endless.

Let's get cracking at it. 

Stay curious. Stay attuned. Stay excited. Stay creative...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


Scott Fellman
Scott Fellman


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