Botanicals: Classified...

As we become more and more experienced as a community playing with botanical method aquariums, our techniques and approaches have evolved. And we have gotten much better and more sophisticated about developing best practices and classifications. When it comes to the materials themselves, we have more to choose from than ever before-there are all sorts of different types of materials with different applications for use.

I think that if we had to break them down into very specific "usage categories", it would be a bit challenging, but it is sort of doable. In the grand scheme of things, virtually any botanical material which you place in the aquarium will have some impact on the environmental conditions. 

I break them down into three broad classes, based on how long they last while submerged, and what their "best use" would be in the aquairum:





Some materials are quite durable, and last a long time-perhaps indefinitely- when submerged. I classify them as "permanent." However, some materials, such as leaves, are more "ephemeral" in nature, in that they break down and ultimately decor pose more quickly than others. Other materials, like bark, sort of "walk the line" between "permanent" and "ephemeral", and I classify them as "transitional" materials.

And of course, even within these broad "classifications", there are variations. For example, some leaves- such as oak- last an incredibly long time without fully decomposing, whereas others, such as Catappa, break down rather quickly.

Some hobbyists have commented that, as their leaves- and botanicals- break down that the physical "aquascape" as initially presented changes significantly over time. Wether they know it or not, they are grasping the Japanese philosophy of  "Wabi-Sabi", as preferred by the late Akashi Amano...well, sort of. A philosophy which asserts that one must appreciate the beauty of life at various phases to appreciate it. To find little vignettes- little moments- of fleeting beauty that need not be permanent to enjoy.

Yes, these categories are useful, IMHO.

I plan on making much more use of these categories when we launch our new website. My hope is that these classifications become part of our "nomenclature" within the botanical method aquarium community. This will facilitate a better understanding about how to employ various materials, and create a better way to communicate and prompt discussions with our fellow hobbyists about how and when we use them.

This is sort of important to think about. 


Well, when we consider which botanical materials we intend to use in our tanks, we should give some thought as to what our purpose for including each one is. For example, if you're like me, and are really trying to foster an ecology within the aquarium, you should include a healthy portion of more "ephemeral" materials. These will break down faster, and create "fuel" for the colonization and proliferation of microorganisms and fungi.

The more durable, "permanent" materials will also foster fungal growths and biofilms on their surfaces, but are much slower to break down, and less likely to impart significant amounts of compounds like tannins, humid substances, etc. into the water. 

If you'll notice, I don't mention anything about "tint capability" within these classifications because: a) that's an aesthetic attribute, b) it is generally pretty obvious which materials do tend to impart color producing tannins into the water, and c) it's not entirely relevant to our main goal of cultivating an ecology within the aquarium.  

Obviously, to many hobbyists, the "tinting capability" of various botanicals IS important, and if you ask us, we can (and always have) make recommendations about which materials will produce these superficial effects most readily and easily.

As we touched on briefly, some botanical materials are better suited at physically and structurally enhancing the aquarium environment, and eliciting and complimenting various behaviors among our fishes. For example, larger, hollowed-out materials like Sterculia pods, Carinaina pods, and "Monkey Pots" are most useful as hading spaces, territories, and spawning locations for fishes like Apistogramma and other dwarf cichlids.

While they will provide surface area for colonization of bacterial biofilms, fungal growth, and epiphytic algae, their primary "strength" in the botanical method aquarium is to serve as one of the aforementioned "physical/structural" roles.

Other materials, like twigs and roots- what we would classify as "transitional" materials- are perfect for creating a more complex benthic environment within the aquarium, being perfect to layer with leaves and other more ephemeral materials. They will soften and break down over much longer periods of time than say, leaves, but will provide a variety of benefits during their "useful life" while submerged.

The utility of botanicals is as diverse and comprehensive as the number of botanicals in existence!

One of the most amazing things about our practice of adding leaves, twigs, seed pods, and other botanical materials to our aquariums- whether you collected them yourself in Houston, Hamburg, or Hong Kong- or purchased them from a supplier like us-is that most can be almost "relied on" to perform in a fairly predictable manner in our aquariums.

The same natural processes which affect the decomposition of an Alder Cone from Europe impact the Sterculia pod from Southeast Asia, the oak twig from North America, the Jackfruit leaf from Malaysia, or the Banana Stem from Thailand. Colonization by biofilms, fungal growths, and the resulting decomposition which occurs are the same all over the planet.

And they're the same processes which govern what happens in our aquariums.

Think about that for just a second. Let me rephrase it one more time:

The same processes of Nature which impact the leaves when they fall into the water in the Amazon occur in your home in suburban Los Angeles, Paris, or Tokyo, for that matter.

Nature doesn't care. 

Sure, there are subtle chemical, mineral, and other physical variations in the tap water in different parts of the world, which, if I'm being intellectually honest, could make some difference-but the ecological processes which decompose leaves are the same.

It's actually pretty remarkable, when you think about it!

When viewed as a "whole", the macro view of a botanical-method aquarium is that it challenges us to look at the big picture- to not get too caught up in any one aspect of creating or managing our aquarium...and to appreciate all of the process by which Nature does its work. And to make a "mental shift" to understand that everything we see in the aquarium is exactly what Nature intends. 

I think we're starting to see a new emergence of a more "holistic" approach to aquarium keeping...a realization that we've done amazing things so far, keeping fishes and plants in a glass or acrylic box with applied technique and superior husbandry...but that there is tons of room to experiment and push the boundaries even further, by understanding and applying our knowledge of what happens in the real natural environment. 

You're making mental shifts...accepting these processes and attempting to replicate the function of natural aquatic habitats in our aquariums by achieving a greater understanding of Nature in general.

Wow, as usual, I drifted into "Philosophical Mode" here. 

So, yeah, that's all well and good, but which seed pods and leaves are acceptable for aquarium use, besides just the ones that we offer for sale? 

I simply can't tell you!

Besides, should we assume that all botanical materials impart the same substances into the water? Damn, who could possibly know that for certain? Better to do your homework. If collecting the damn stuff is the easy part, shouldn't figuring out WTF they do be at least a tiny bit of a challenge? Yeah!

I suppose it starts with proper identification of what you're collecting, and understanding what your intent is when using botanical materials in your aquarium. For me, it's about fostering an ecology- and that ecology includes bacteria, various other microorganisms, and perhaps our most important friends, the fungi.

Yeah, you heard me. Fungi.

Fungi reproduce by releasing tiny spores that then germinate on new and hospitable surfaces (ie, pretty much anywhere they damn well please!). These aquatic fungi are involved in the decay of wood and leafy material. And of course, when you submerge terrestrial materials in water, growths of fungi tend to arise.

Anyone who's ever "cured" a piece of aquatic wood of almost any type for your aquarium can attest to this! It's absolutely pervasive in Nature, along with bacterial biofilms- an indespensible benefit to the higher aquatic organisms which reside in these aquatic habitats.



Fungi tend to colonize wood ( and by extension, botanical materials) because they offer them a lot of surface area to thrive and live out their life cycle. And cellulose, hemicellulose, and lignin- the major components of wood and botanical materials- are degraded by fungi which posses enzymes that can digest these materials! Fungi are regarded by biologists to be the dominant organisms associated with decaying leaves in streams, so this gives you some idea as to why we see them in our aquariums, right?

And of course, fishes and invertebrates which live amongst and feed directly upon the fungi and decomposing leaves and botanicals contribute to the breakdown of these materials as well! Aquatic fungi can break down the leaf matrix and make the energy available to feeding animals in these habitats.

These bacteria and fungi are all participants in a rather grand process of nutrient utilization- both in Nature, and in our aquariums. And it all starts with adding botanicals and leaves to our systems. This is absolutely analogous to what happens in Nature.

When leaves enter tropical streams and other bodies of water, fungal colonization causes leaves to increase nitrogen content (because of fungal biomass) and leaf maceration. This is thought by aquatic ecologists to be evidence of microbial colonization. There are many different stages in the process, starting with the leaching of materials from the cells of the botanicals during initial submersion, in which soluble carbon compounds are liberated in the process. A rapid release of phosphorus accompanies this leaching.

Of course, the process ultimately leads to physical breakdown and/or fragmentation of the leaves and botanicals into smaller "pieces", which possess larger amounts of surface area for microbial attachment.  Extensive ecological studies done by scientists specifically in regard to leaf litter have yielded a lot of information about this process.

The fungi known as aquatic hyphomycetes produce enzymes which cause leaf maceration, and in as little as 2 to 3 weeks, as much as 15% of the decomposing leaf biomass in many aquatic habitats is processed by fungi, according to one study I found.

In experiments carried out by aquatic ecologists in tropical forests in Venezuela, decomposition rates were really fast, with 50% of leaf mass loss in streams occurring in less than 10 days!


The ultimate result of this process is the transformation of what ecologists call "coarse particulate organic matter" (C.P.O.M.) into "fine particulate organic matter" (F.P.O.M.), which may constitute an important food source for other organisms we call “deposit feeders” (aquatic animals that feed on small pieces of organic matter that have drifted down through the water and settled on the substrate) and “filter feeders” (animals that feed by straining suspended organic matter and small food particles from water), as well as worms, planaria, and insects.

And of course, these organisms and their processes create not only the basis of a food web, but the development of an entire community of co-dependant organisms which work together to process nutrients and support life forms all along the chain. When we encourage, rather than remove these organisms when they appear, we're helping perpetuate these processes. I can't stress how important it is to let these various organisms multiply.

And, as I've mentioned numerous times here- we need to think about our relationship with detritus, decomposing botanical materials, and sediments in our tanks.

Yes, I'm asking you to not only "leave them be" -but to encourage their accumulation, to foster the development and prosperity of the organisms which "work" them. 

Now, again, I have to at least ask the rather long question, "Are these things (detritus; decomposing materials) really problematic for a well-managed aquarium? Or, do they constitute an essential component of a closed aquatic ecosystem...One which can actually provide some benefits (ie; supplemental nutrition) for the resident fishes and the community of life forms which support them?"

I think that I know the answer...

Many of us have 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 ecodivesity is simply the next iteration in the management of blackwater/brackish botanical method aquariums.

So, yeah- there IS a lot to consider when utilizing botanical materials in your aquarium. It's far, far beyond the idea of just "dumping and praying" that has been an unfortunate "model" for how to utilize them in our aquariums for many years. It's more than just aesthetics alone...the "functional aesthetic" mindset- facilitating ecological processes, while accepting the look and the appearance of various life forms which occur when terrestrial materials break down in our tanks is a fundamental shift in thinking.

By studying and encouraging the growth of this diversity of organisms, and creating a multi-faceted microcosm of life in our tanks,  I believe that we are contributing to an exciting progression of the art and science of aquarium keeping!

Wow- I went from talking about a general classification system for botanical materials to the whole damn treatise on the botanical method approach once again...Okay, there's a whole lot there to unpack- drawing from a variety of scientific fields, such as biology, chemistry, and ecology, as well as from our everyday practices as aquarists.

And, because someone will inevitably ask about "tannins" in relationship to our botnaicals- the answer is, we still don't know exactly which tannins are imparted to the water by a specific botanical. And for that matter, we don't know which tannins provide what specific effects on fishes or their aquatic environment, and what concentrations are found in their natural habitats. It simply hasn't been studied, to the best of my knowledge.

And again, it's not necessarily that we are creating a new "thing"- we're simply seeing a correlation to the processes that we are fostering in our aquariums and what occurs in Nature, and realizing that we can embrace, study, and benefit from them in our aquarium work.

I think that there are so many different things that we can play with- and so many nuances that we can investigate and manipulate in our aquariums to influence fish health and spawning behavior, like changing botanical concentrations and such during various times of the year- recreating ephemeral aquatic systems and other unique environmental-themed displays, etc. 

Yes, once again, a discussion about some esoteric features or attributes of botanicals ends up with me waxing philosophical about the ecology of the botanical method aquairum. It's such an important thing- developing an understanding about how something seemingly as inconsequential as which botanicals we choose to employ in our aquarium can influence such a wide range of factors.

Stay open to new ideas, experiences, and interpretations. Look to Nature as a key influence in your aquarium designs, and your selection of botanical materials...Share your revelations, thoughts, and experiences with other hobbyists. Enjoy the benefits of such experiments...

Stay enthralled. Stay creative. Stay open-minded. Stay intrigued...

And Stay Wet.


Scott Fellman

Tannin Aquatics


Scott Fellman
Scott Fellman


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