Painting with the broadest strokes...or just grasping? Or something else still?

There is something comforting about the knowledge that you must be doing something right, huh?


Wow, that’s a very arrogant way to start, I know…but this is something that I’ve been thinking about for a while.

Like, I keep hearing from fellow hobbyists-recent converts to our blackwater, botanical-style obsession…and they will proudly relate to me the story that their Apistos, which have been hesitant to do much of anything, suddenly spawned a week after they started utilizing botanicals in their aquarium…

Or that "ugly grey Barb" suddenly started to get really colorful not long after!

Stuff like that.


I mean I probably DO sound like a bit of an arrogant jerk when I say this, but man, there really is something in the water…I think that the humic substances, tannins, and other compounds which are imparted by leaves, seed pods, and wood, too- create environmental conditions that, while maybe not exactly what our fishes might encounter in say, the rain forests of Asia or the jungles of South America, are similar in some respects.

Remember, these environments are replete with botanical materials from the surrounding forests and soils- and all of these materials have some chemical impact on the water.


What specifically is it about the presence of leaves and other botanicals which seems to have some sort of beneficial impact on our fishes? Well, the humic substances (I know, as big a “catch all” term as “tannins”) are documented by science to play an important role in fish health- specifically, cellular repair, stress reduction, metabolism, and disease resistance. I mean, yeah- these are BIG important things for fish health, aren’t they?



These substances aren’t present in just “any old aquarium”, filled with gravel, plants, and a few rocks. The ones we’re referring about come from plant materials- in our case, seed pods, leaves, bark, and other parts of the plants in a given habitat. This is really important. And we know for a fact that they are found in the stuff that us “Tinters” throw into our tanks. 


Now, just throwing botanicals and leaves into your aquarium filled with tap water won’t give you an “Instant Amazon” effect. You’ll need to reduce the pH and carbonate hardness by utilizing proper water conditioning (ie; reverse osmosis/deionization). However, you will be able to impart some of the tannins, humic susbtances, and other compounds into the water to a positive effect, even if you don’t pre-condition your water via RO/DI.

As we’ve said repeatedly- adding botanicals to your water will NOT lower the carbonate hardness. It might knock down the pH by a very small number ( like maybe .1 or .2). What you will get is some tinted water. You’ll get an aesthetic for sure. 


And you will get some benefits of the humic substances. I’m not 100% certain why it is, but one of my scientist friends confirmed for me that humic substances, which are found in all sorts of aquatic environments (ranging from soft, acidic water to full-strength seawater). Which humic substances? What tannins? Like, that’s the $40,000,000 question, right?


I am not aware of any definitive study that examined what humic substances and which specific tannins are present in a given habitat somewhere out there in the tropical streams, rivers, and lakes of the world. Could you imagine if we knew WHICH ones and in WHAT concentration are found in specific locales? It would only be am after of time before we would know how to create synthetic formulations of location-specific “humic/tannin cocktails”, which, when added to pH/hardness-appropriate water, could, in theory, yield conditions extremely close to those you might encounter in nature.


Welcome to the aquarium hobby- 2075 edition, right? So for now, we will jus sort of have to guess…and take a more-or-less “shotgun approach”, and just add leaves and botanicals to our tanks in the hope that some of these beneficial substances will leach out into the water column over time while they’re submerged in your aquarium.


Hey, it’s not as sexy as the “Open-bottle-add-super-specialized-formulation-for-the- Upper-Rio-Negro", but it’s a start, right? I liken it to an artist, painting with a very broad stroke to cover a  lot of blank canvas.

Yeah, we’re artists. And this stuff is really as much of an “art” as it is a “science”, IMHO. There is so much we don’t know yet. Or, more specifically, so much we don’t know in the context of keeping fishes. We need to tie a few loose ends together to get a really good read on this stuff…until we get to the "Dial-a-River” additive approach.


And I”m not all that sad about it. There is something so satisfying about playing with the natural materials, and letting them influence the water- however random or un-scientific that may be- as they have done for eons. Using our experience, observation, and of course, our test kits, when applicable.

And always, our intuition.

Stay curious. Stay bold. Stay excited...

And Stay Wet.


Scott Fellman

Tannin Aquatics






Scott Fellman
Scott Fellman


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