Benefitting from the breakdown...

As we are all aware by now, a derivative of the old expression, "What goes up must come down!" sort of applies to the botanical-style, blackwater aquarium. In our case, "What goes down must BREAK down" is the tagline!

Yeah, as we know, the very essence of our "practice" is the understanding and acceptance that terrestrial botanical materials, when exposed to water, begin to soften and decompose, not only releasing their constituent tannins and other organics into the water, but physically reducing to smaller, finer particles. It's among the most accepted and well-understood processes in aquarium keeping, and of course, in nature. The breakdown of materials by the action of water, bacteria, and organisms is part of the wonderful function of aquatic environments.

From the minute we place a leaf, seed pod, other botanical, or even a piece of wood into our aquariums, various forces act upon them to begin softening and breaking them down. And of course, this process is aided by fishes and shrimp, which tend to graze upon these surfaces, either feeding on the biofilm and algae which populate them, or the tissues of the materials themselves. 

Ultimately, what you will end up with is extremely fine, detritus-like material that will accumulate either in pre filter sponges, filter pads, or in the substrate of the aquarium. Essentially, you've involuntarily created a sort of "aquatic mulch" by allowing botanicals to "do their thing" and break down in the aquarium. I can't help but wonder about the value of this material, both as a substrate for benthic life forms, and for the growth of aquatic plants as a sort of homemade "soil additive." Happily, some hobbyists, such as the ridiculously talented Cory Hopkins, are experimenting with this, and early results are proving interesting!

And, with the interesting fusion of aquatic plants and botanicals that more and more hobbyists are starting to play with, the implications could prove interesting in the long term. I admit that I'm not even close to being a competent aquatic plant specialist, but it doesn't take an expert to see that the possibilities for utilizing an "active botanical bed" in a planted tank to perhaps supplement the plants with natural, "in situ" nutrient production is compelling! Will a bed of mixed botanicals, if allowed to fully mineralize and break down over time, become a meaningful and useful source of nutrients for aquatic plants? Only time and more experimentation will tell!

As you probably know from general experience, science classes, and maybe reading my ramblings here in "The Tint", many tropical aquatic ecosystems which contain leaf litter and other botanicals are host to many, many life forms, including bacteria, fungi, insects, aquatic crustaceans, and of course, the fishes we love so much! 

Back to the flooded forests of Amazonia...again. These rich habitats are not only productive, but are some of the more "populated" feeding grounds for fishes, with significant populations of fishes known to be insectivores, that consume immature insects of the families Chironomidae (Diptera), Baetidae, and Leptophlebidae (Ephemeroptera). It's a diverse mix of life which creates the basis of a significant food chain. Now, I have no illusions of creating a full-blown food chain, complete with developing flies and mosquitoes in our aquarium. (especially for those of us in domestic relationships we value!). However, I think that it may be possible to recreate or at least develop partial food chains, supporting bacteria, fungi, and aquatic crustaceans/worms in our botanical-style systems


And of course, the literal "basis" for all of this stuff is the botanical materials themselves, breaking down in our tanks, as they've done in nature for eons.

We've already made a mental shift which accepts the transient, subtle beauty of decomposing botanical materials, tinted water, biofilms, and the like, so it goes without saying that taking it a little further and allowing these materials to completely breakdown to serve as the substrate for our aquatic ecodiverfity is simply the next iteration in the management of blackwater/brackish botanical-style aquariums.

With more and more emphasis being placed on the idea of "functional aesthetics" in our tanks, it seems only natural that we'll see an increased likelihood of stumbling upon some previously unknown benefit of allowing this complete breakdown of botanicals to occur in our aquariums. Not only will this yield some interesting, extremely natural-looking aquariums, but the implications for the fishes which reside in them are numerous!

I can envision systems created to optimize the breakdown and accumulation of botanicals, with targeted water-column flow, use of more coarse (or fine) mechanical filtration media, moderated lighting to discourage excessive algal growth, and even careful selection of hardscape materials, such as Mangrove root tangles, Manzanita wood, etc. to encourage these materials to settle in and among them, as occurs in nature. Letting our minds wander a bit, and accepting and encouraging this stuff, rather than freaking the %&*@# out every time we see a gram of detritus in our tanks will go a long way towards fostering new discoveries, "best practices", and maybe even breakthroughs! 

Yeah, it's a bit if a "mental stretch" for ourselves yet again- but as a group, we're getting pretty good at this sort of stuff, huh? Brown water, biofilms- and breakdown of botanicals have not only proven to be an exciting new area to play in- they've provided some amazing results for our  fishes as well! They have most certainly "benefitted from the breakdown!"

As always, each and every one of us has the extraordinarily unique opportunity to contribute mightily to the body of work and "state of the art" in our formerly dark, yet increasingly well-illuminated are of the aquarium hobby!

Stay curious. Stay calm. Stay unencumbered by conventionality. Stay bold. And most important...

Stay Wet.


Scott Fellman

Tannin Aquatics 


Scott Fellman
Scott Fellman


2 Responses

Scott Fellman
Scott Fellman

October 31, 2017

This is super cool, Garrett! Been following your experiments on Instagram and I’m enjoying seeing what’s going on in your tanks. So many potential benefits to be had once more hobbyists experiment like you’re doing! Thanks for sharing!



October 31, 2017

I’ve been using spongeless filtration for a few weeks in my blackwater aquariums, relying only on Biomax media to maintain the nitrogen cycle, and I have to say that while it’s certainly unconventional, it’s yielding very exciting results! A greater number of suspended particles (as in nature), accumulation of detritus on and around the hardscape (as in nature) and my filter maintenance has gone from a few times a week to once a month (if I remember – as in nature? :-P). It’s certainly not for everyone or every tank, but for me there have been quite dramatic positive results from such a small change!

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