The power of biodiversity...

Okay, Fellman- If 2020 is truly the "Year of the Substrate", as I've postulated recently, it's probably time to start thinking about the substrate a bit more, right? Now, not just utilizing a new and different array of materials to create more interesting looking and functioning substrates, but to foster specific functions as well.

There has been that curious, nagging "thing" I have in my head about the ability of botanical-influenced substrates to foster denitrification.  I guess, coming from a reef background, where natural materials like sand and live rock are the de facto vehicles for this process, it's only natural that I'd draw a parallel to our work with botannicals.

With the diverse assemblage of microorganisms residing in a layer of leaves, and a continuous food source of decomposing botanicals "in house", I can't help but think that such "living substrates" create a surprisingly diverse and utilitarian biological support system for our aquariums.

The reason we have been working with some of the substrate materials that we offer goes beyond just the fact that they look so different from the usual sand or gravel that we as aquarists tend to use. I feel they offer a tremendous amount of "attachment points" for bacterial biofilms, fungi and even some microalgae- three vital living components of the natural aquatic ecosystem. And, because of their composition, I think that the compounds that they contain are an onboard "carbon source" for beneficial organisms.

With our embrace of "detritus" or "mulm" as a source of "fuel" for creating active biological systems within the confines of our aquariums, I think that the idea of an "enriched substrate" will become an integral part of the overall ecosystems that we create. Considering the substrate as both an aesthetic AND functional component- even in "non-planted" aquariums, opens up a whole new area of aquarium "exploration."

One of the key things to unlock here is to embrace a greater reliance on Nature and the organisms and processes which she fosters to support the higher life forms in our aquariums. I've always sort of laughed at this idea; I mean, on one hand, we've been told over the years about the nitrogen cycle, and we've even had some great "bacteria in a bottle" products available to "jump start" new tanks (I love these products, BTW).

Hobbyists have been encouraged to understand the nitrogen cycle vis a vis starting a new tank...and then we sort of "let it go." We give it no additional thought. The importance of "starting" is accepted, but that's it. Like, it's okay to add some bacterial starter culture ( a clear liquid) to the tank to get things going. But once we're up and running, we're good. And I think the fact that because it's just a few ml of clear "stuff" we're pouring into our tanks, it's not really upsetting to our aesthetic sensibilities.

Kind of "out of site, out of mind." Yet, once the tank is up and running, we give this vital life-sustaining cycle little more thought. And the idea of creating a botanical bed or utilizing leaves for the expressed purpose of continuing to foster biodiversty and overall nitrogen cycle "health" seems a bit tedious or "alien" to us. Because it has a certain look that we likely find upsetting. Kind of a sad reason to not embrace the idea of creating a functional substrate, I think.

I envision that the future of mainstream aquarium practice may include creating such a substrate as simply part of "what we do." Adding a mix of botanical materials, live bacterial and small organism cultures, and even some "detritus" from healthy aquatic systems (which has been a common practice for a long time) may become how we establish systems. I've had some good discussions with my friends about this, and they've thought about this from a planted tank perspective for a while now. Bacterial substrate additives for plant tanks have been used for a while in the various regimens manufacturers recommend.

The idea of specifically trying to foster this type of biodiversity for non-plant-focused tank has been suspiciously absent from the hobby, IMHO.

Other botanical-style aquarium enthusiasts have done remarkable things with this idea, fusing the idea of a biologically active substrate for an aquarium that has some plants, but focuses more on the "overall picture."

And thats where it gets really interesting to me. The idea of embracing natural materials and utilizing them in the display for the specific goal of helping to foster functional biodiversity, with "aesthetics" as the secondary benefit is a quantum leap forward in aquarium technique, IMHO. 

The implications for successful aquariums are manifold.

I mean, it's not THAT crazy.  It makes sense, and the overall concept is really not that difficult to grasp. And we probably shouldn't get too crazy into understanding every single aspect of this practice. Yet, I think that if more new aquarists were perhaps encouraged to create beds of leaves and botanicals and such, there could be a lot more continued success. Of course, it requires a lot of "reprogramming" and mental shifts on everyone's part to accept this as "normal technique!"

The look of such substrates just doesn't appeal to everyone.

And of course, there is a lot to learn.The biochemical interactions and such can and should be explored by those with the proper backgrounds, but for most of us, simply observing our aquariums and the way they operate can yield a surprisingly large amount of information. Something about this  practice works, for reasons which we already tangentially understand.

However, there is lots more to learn. The idea of fostering biodiversity in all sorts of aquariums- not just blackwater/brackish botanical-style tanks is fascinating and really not well studied. Again, I think it might have been a case of the "look" of such aquariums discouraging soem people from trying this stuff. The aesthetics of more "high concept" tanks seem to be more appealing.

Yet, we've seem some very cool, artistically-minded botanical-style aquariums lately that I think may change a few minds. Some of the materials can even be "tucked away" in parts of the hardscape to avoid the typical "busy-looking" substrate we see a lot in our world.

There are a lot of approaches to fostering this kind of biodiversity in our aquariums.

Interested? I sure am!

It's not some amazing "revolution"- it's simply an evolution of practices that we've been playing with peripherally for decades in the hobby. It's a way of looking at what's already working and trying to figure out the "whys" as we go. 

In the mean time, I'm going to keep playing with different substrate materials, and mixing botanicals and such into my substrates. It's too irresistible for me not to do this! I can only hope we as a community get into this concept more and throw some creativity at it!

Stay thoughtful. Stay progressive. Stay brave. Stay curious. Stay experimental. Stay   diligent...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


Scott Fellman
Scott Fellman


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