Even with the exploding popularity of botanical-style aquariums, I still receive many questions from hobbyists unfamiliar with our practice, asking what the purpose or benefit is of utilizing these materials in our tanks. I find myself repeating the mantra that this is not purely an aesthetic statement.
Utilizing natural botanical materials in our aquariums is not an aquascaping style; rather, it's a methodology for creating and managing a biologically diverse closed aquatic ecosystem.
There is also something very different about the way that our fishes behave when they are living in an environment which has an abundance of natural materials present.
I know, it sounds a bit weird, but it's true! We receive lots of comments about this. It's sort of an "intangible" that comes with using them in our tanks. And I suppose it makes a lot of sense, as the fishes are utilizing them much as they do in their wild habitats, for shelter, grazing, and spawning.
Now sure, in a tank devoid of natural materials like botanicals, fishes will utilize whatever materials are available to shelter among, graze, and even spawn (hello, "spawning cones" and cracked flower pots!). Yet, there is a certain "something" that's different when you use botanicals. You can just see it.
Of course, with botanical materials, you have the added benefit that they are natural materials, consisting of substances like lignin, and they can impart other compounds stored in their tissues, such as tannin and humic substances, into the surrounding water column. And many fishes feed directly on the botanicals themselves, or remove "biocover" from their surfaces.
Yeah, think about it:
The texture and chemical composition of the botanicals' exteriors is really well-suited for the recruitment and growth of biofilms and fungal populations- important for the biological diversity and "operating system" of the aquarium, as we've talked about numerous times here. This is such an easily overlooked benefit of using natural materials in the aquarium.
And of course, as we know, terrestrial botanical materials, when submerged in water for extended periods of time, decompose. If there is one aspect of our botanical-style aquariums which fascinates me above almost anything else, it's the way they facilitate the natural processes of life- specifically, decomposition.
Decomposition is fundamental to the botanical style aquarium.
We use this term a lot around here...What, precisely does it mean?
de·com·po·si·tion- dēˌkämpəˈziSH(ə)n -the process by which organic substances are broken down into simpler organic matter.
A very apt descriptor, if you ask me!
We add leaves and botanicals to our aquariums, and over time, they start to soften, break up, and ultimately, decompose. Decomposition of leaves and botanicals not only liberates the substances contained within them (lignin, organic acids, and tannins, just to name a few) into the water- it serves to nourish bacteria, fungi, and other microorganisms and crustaceans, facilitating basic "food web" within the botanical-style aquarium, just like it does in Nature- if we allow it to!
PVC pipe sections, flower pots, and plastic plants can't do THAT!
Utilizing botanical materials and leaves in your tank, and leaving them in until they fully decompose is as much about your aesthetic preferences as it is long-term health of the aquarium.
It's a decision that each of us makes based on our tastes, management "style", and how much of a "mental shift" we've made into accepting the transient nature of materials in a botanical-style aquarium and its function. There really is no "right" or "wrong" answer here. It's all about how much you enjoy what happens in Nature versus what you can control in your tank. Nature will utilize them completely, as she does in the wild.
I tend to favor Nature, of course. But that's just me.
And of course, we can't ever lose sight of the fact that we're creating and adding to a closed aquatic ecosystem, and that our actions in how we manage our tanks must map to our ambitions, tastes, and the "regulations" that Nature imposes upon us.
Yes, anything that you add into your aquarium that begins to break down is bioload.
Everything that imparts proteins, organics, etc. into the water is something that you need to consider. However, it's always been my personal experience and opinion that, in an otherwise well-maintained aquarium, with regular attention to husbandry, stocking, and maintenance, the "burden" of botanicals in your water is surprisingly insignificant.
Even in test systems, where I intentionally "neglected" them by conducting sporadic water exchanges, once I hit my preferred "population" of botanicals (by buying them up gradually), I have never noticed significant phosphate or nitrate increases that could be attributed to their presence.
Understand that the process of decomposition is a fundamental, necessary function that occurs in our aquariums on a constant basis, and that botanicals are the "fuel" which drives this process. Realize that in the botanical-style aquarium, we are, on many levels, attempting to replicate the function of natural habitats- and botanical materials are just part of the equation.
And of course, these botanical materials not only offer unique natural aesthetics- they offer enrichment of the aquatic habitat through their release of tannins, humic acids, vitamins, etc. as they decompose- just as they do in Nature.
Leaves and such are simply not permanent additions to our 'scapes, and if we wish to enjoy them in their more "intact" forms, we will need to replace them as they start to break down. This is not a bad thing. It just requires us to "do some stuff" if we are expecting a specific aesthetic.
This is very much replicates the process which occur in Nature, doesn't it? Stuff like seed pods and leaves either remains "in situ" as part of the local habitat, or is pushed downstream by wind, current, etc. - and new materials continuously fall into the waters to replace the old ones.
Pretty much everything we do in a botanical-style blackwater aquarium has a "natural analog" to it!
Despite their impermanence, these materials function as diverse harbors of life, ranging from fungal and biofilm mats, to algae, to micro crustaceans and even epiphytic plants. Decomposing leaves, seed pods, and tree branches make up the substrate for a complex web of life which helps the fishes that we're so fascinated by flourish.
Intangibles? Perhaps. Yet, highly beneficial and consequential ones, indeed.
Stay persistent. Stay bold. Stay consistent. Stay observant...
And Stay Wet.