The to do list just got bigger...


It seems like the more we talk about new ideas in the botanical/blackwater aquarium world, the more other new ideas pile up on top of them! This is a really cool thing, because it shows just how much "pent up" creativity and energy there is in the minds of fish geeks around the world. Apparently, we're all itching to try new things, make improvements, and do experiments . We're executing, instead of just postulating, which I totally love. 

Well, "Tint Nation", I have some more assignments for you for 2017. Some of these might prove to be pretty awesome ideas to play with- others, might just yield some marginal improvements over how we've done stuff in the past. Some might lead to "crash and burn" disasters- others, compelling and successful outcomes. That's the price of progress, right? Let's begin the exploration with a topic I'm fascinated in, and I know that some of you are, too! 

"Alternate substrates, Part X": How about some more investigation into how substrates, perhaps consisting of shallow levels of very coarse pebbles and finer sand, interspersed with a deeper bed of a few types of botanicals and leaves- or just "all botanical" aggregations- the so-called "deep botanical beds" function?  Besides perhaps putting to rest long held hobby concerns about the "dangers of detritus", what else could experimenting with such substrates unlock? Well, a sort of "cadence", for one thing.  We know from experience that adding a lot of material to any tank at one time is a recipe for problems. In fact, virtually every bad outcome (and we have only seen/heard of a very few) we know of has been caused by adding a lot of material all at once to an established system. It seems that, even when building a deep botanical bed, you need to do it slowly. We know a few things, for sure- many of these materials will recruit fungal growth and biofilms. Many aquatic creatures, from shrimp to Plecos, will actively forage among such an aggregation of materials. 

What I'm curious about is how these types of alternative substrates function over the long term (a year or more) in an aquarium. Of course, the initial aquarists' instinct is to warn about "detritus accumulation, lack of circulation, depletion of oxygen", etc. And most of this is valid and worth consideration- absolutely. It's also been postulated, from personal conversations with some of you, that at some point very deep leaf litter/botanical beds can possibly  become "oxygen drains" in aquariums if not managed correctly. "Managing correctly" consists of stronger aeration, surface agitation, and good overall maintenance.  I wonder what the practical limit of botanical/litter bed depth is in anaquairum before it becomes such an issue. And how does the lower pH in blackwater aquariums synch with this?

I wonder exactly what goes on in the deep botanical layers?

Anerobic activity? Production of hydrogen sulfide gas? Fermentation? Denitrification, even? Interesting side note: In natural leaf litter beds, it's been postulated that fungi, not bacteria are the primary decomposers in lower pH habitats. In fact, researchers wonder what exactly causes such low pH readings in some of these systems (into the 3's or lower!). Humic acids are apparently not strong enough to bring down pH to such extreme levels. A possibility suggested by some researchers is that fermentation within the litter beds is releasing strong organic acids, such as acetic acid.

So, what- are we making kombucha in our aquariums?

Does the same process which occurs in a wild deep litter bed happen in an aquarium? Is there enough input to "fuel" such reactions?  And who runs an aquarium at 4.0pH right now, anyways? I know some who are experimenting with this region, so I think we'll see some interesting stuff soon...

Another interesting idea that has been discussed by a number of hobbyists in our community, as touched on above, is the possibility that "deep botanical beds" are performing some sort of dentrification process, similar to that which occurs in a deep sand bed in a reef aquarium. Of course, as a reefer, I'm starting to think about carbon dosing. biopellets, etc., and wondering if botanicals are functioning in a similar capacity within a freshwater aquarium, driving bacteria growth and ultimately, denitrification/phosphate reduction?

Now, most big-time botanical "users" (including myself, BTW) will tell you that they have no detectible nitrate (or phosphate, of that matter) in their systems. Interesting, because you'd think that with all of that botanical material breaking down in the confines of an aquarium, something would be up. Could there be a very efficient population of bacteria that process nutrients within a healthy botanical-style blackwater system with a large quantity of these materials? Could it be? Or is it something else? If so, what? Denitrification is interesting...I find this a very fascinating possibility. In general, I find the process of how aquatic systems assimilate organic matter very interesting, and I know many of you do, too...Good area to look at!

It seems that "one you get it down", the botanical-style blackwater aquarium operates in a surprisingly stable manner. Have you noticed that? I mean, we are still sort of finding our way in some areas, but for the most part, these tanks run really well.

Yeah, all of this is just speculation, and anecdotal observation, and the science behind a lot of it is getting well "above my pay grade" as they say...Some serious research by individuals with the academic background and/or research abilities on some of these subjects would be interesting! If you've got the lab- we've got the botanicals... hint, hint.

We are pushing in some unique directions, far beyond just aesthetics. Are there some dangers to pushing out the boundaries a bit? You bet. Will there be disasters; failures? Without doubt. Will there be new discoveries? Yes! Are there rewards for assuming the risks? Absolutely. Perhaps the best "reward" is the knowledge that we gain along the way. Knowledge which not only will help ourselves and fellow hobbyists in our aquarium endeavors- knowledge that will perhaps provide a greater understanding for the precious natural environments from which our fishes come from.

Couldn't ask for any more than that.

Stay adventurous. Stay curious. Stay bold.

And Stay Wet.


Scott Fellman

Tannin Aquatics


Scott Fellman
Scott Fellman


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