An embarrassment of riches?

I have some very specific tastes when it comes to my aquariums. I like a certain "look" or "vibe"- and it just so happens that my preferred aesthetics result from utilizing botanical materials which have some ecological/chemical impacts on the environment of my aquariums.

And, at this stage in the world of botanical-style aquariums, we have a real "embarassment of riches"- a vast "portfolio" of botanical materials which we can use in our aquariums to impact the aesthetics and function of them. 

It's pretty much a given that every aquarium that we assemble is not only a unique expression of our interests and skills- it's a complex, ecologically functional microcosm, which is impacted by not only the way we assemble the life forms, but how we utilize them.

And of course, being the self-appointed "World's most prolific aquarium hobby philosopher,"  I have spent a fair amount of time ruminating on the idea, attempting to grasp the concept. I think it simply starts with the materials that we use.

We've pretty much beaten the living shit out of the idea that It is perfectly logical to imply that botanicals, wood, and other materials which we ultiize in our aquascapes not only have an aesthetic impact, but a consequential physical-chemical impact on the overall aquatic environment, as well.

Not really difficult to grasp, right? You put stuff into the water- it influences the aquatic environment its emerged in...

And, different botanical materials can impart different "effects" to the water, based on the composition, origin, and concentration of the botancials. This is hardly a novel concept when you think about it in the context of stuff we know and love in other areas of life.

Wine, for example, has "terroir"- the environmental conditions, especially soil and climate, in which grapes are grown and that give a wine its unique flavor and aroma... Coffee, too, acquires traits that are similar. Tangible effects and characteristics, which impact the experience we get from them.

And of course,  I can't help but wonder if this same idea applies to our botanicals?

It must!

I mean, leaves come from specific trees, imparting not only tannins and humic substances into the water, but likely falling in heavier concentrations, or accumulating in various parts of rain forest streams or inundated forest floors at particular times of the year, or in specific physical locales with in a stream or river.

And of course, they likely provide the fishes which reside in that given area a specific set of physical/chemical conditions, which they have adapted to over time. And, since we are now rather specific about considering the regions from which our botanicals come from, we have at least an outside shot at offering our fishes materials (and the chemical constituents and compounds they contain) which may impart characteristics to the water which are extant in said regions, right?

Is this not the very definition of "terroir?"

Yeah, sort of...right? 

Actually, I think it makes perfect sense.

As we've discussed before, the soils, plants, and surrounding geography of an aquatic habitat play an important and intricate role in the composition of the aquatic environment.

And, in turn, natural botanical materials influence the soils and even the water chemistry of the regions in which they are found to a certain extent. Of course, sometimes, you have to "cheat" just a bit, I suppose.

Case in point:

I remember not long ago reading in some forum on Killififsh that a certain African species needed selenium (Se) in its water, because the soil in the region from which it comes has high levels of the stuff. That's logical, because many plants require this substance in order to grow properly, so it makes sense that fishes which come from waters that are adjacent to these soils would be accustomed to higher concentrations of it than those from other regions, right?

Hobbyists were discussing adding Brazil nuts and such to their tanks. I mean, we offer the so-called "Monkey Pot" -which is the "fruit capsule" which protects the Brazil nut. Could it somehow "impart" selenium into the water?

Perhaps, maybe? Oh, but it's from the Lecythis pisonis tree, found in...Brazil. As are Brazill Nuts, of course.

And the killie is from...Africa.


Well. I suppose fish breeders can make such accommodations without guilt, right? 

I think it circles back, of course. Likely, there are other botanical materials from Africa which have higher levels of selenium contained in their tissues, right?

Biotope people would likely not take too kindly to seeing Monkey Pots in an African-themed aquarium, right?

I think that even the most hardcore biotope aquarium hobbyists- whom I respect and love- seem to focus more on outward appearances for their biotope tanks than they do on function and this "geo-physiological/functional" thing.

I don't think a fish breeder, who's looking more toward results in spawning her fishes is hung up on using a botanical from Brazil in her bare-bottomed breeding tanks or water pre-treatment containers...

And I suppose it's a matter of practicality, really. The goal for these people is to get their fish to breed. Period.

So, to make a long story short, botanical materials have multiple impacts on the aquatic habitats we create for our fishes.

They influence not only the chemical characteristics of the water (like pH, TDS, alkalinity), but the color (yeah- tannins!), turbidity, and other characteristics, like the water flow. Large concentrations become physical structures in the course of a stream or river that affect the course of the water.

And of course, they also have important impact on the diet of fishes...Remember allochthonous input form the land surrounding aquatic habitats? And the impact of humic substances?

I can't help but wonder what sorts of specific environmental variations we can create in our aquarium habitats; that is to say, "variations" of the chemical composition of the water in our aquarium habitats- by employing various different types and combinations of botanicals and aquatic soils.

I mean, on the surface, this is not a revolutionary idea...We've been doing stuff like this in the hobby for a while- more crudely in the fish-breeding realm (adding peat to water, for example...), or with aragonite substrates in Africa Rift Lake cichlid tanks, or with mineral additions to shrimp habitats, etc.

In the planted aquarium world, it's long been known that soil types/additives, ie;  clay-based aquatic soils or substrates high in potassium, or whatever, will obviously impact the water chemistry of the aquarium far differently than say, iron-based soils, and thusly, their effect on the plants, fishes, and, as a perhaps (unintended) side consequence, the overall aquatic environment will differ significantly as a result.

So, it pretty much goes without saying that the idea that utilizing different types of botanical materials in the aquarium can likely yield different effects on the water chemistry, and thus impact the lives of the fishes and plants that reside there- is not that big of a "stretch", right?

I can't help but wonder what the possible impacts of different leaves, or possibly even seed pods from different areas can have on the water and overall aquarium environment.

The biggest problem, as I see it- is that we don't have any "chemical analysis" of the materials contained in the botanicals we use. For that matter, most of us wouldn't really know what concentrations we'd need for specific effects, or to take advantage of a given concentration of ______ that is contained in a specific botanical, right?

And, with few exceptions, we don't even know which compounds from which regions benefit our fishes in specific ways! So, we have to take a sort of "shotgun approach" and at least infer that a botanical from a given region has some of the compounds found in the soil or aquatic environment of the region. A bit of a stretch, I know, but it's the best we can do for now, I think.

There's so much "unknown" stuff here, right?

We just don't have the data.

We know some impacts, of course.

I mean, sure, pH and such are affected in certain circumstances - but what about the compounds and substances we don't- or simply can't- test for in the aquarium? What impacts do they have? Subtle things, like combinations of various amino acids, antioxidant compounds, obscure trace elements- even hormones, for that matter...Could utilizing different combinations of botanicals in aquariums potentially yield different results?

And could we develop "recipes" of sorts to know what to use? You know- scenarios like,  "Add this if you want fishes to color up. Add a combination of THIS if you want the fishes to commence spawning behavior", etc.

It sounds a bit exotic, but is it really all that far-fetched an idea?

Absolutely not, IMHO.

I think the main thing which keeps the idea from really developing more in the hobby- knowing exactly how much of what to add to our tanks, specifically to achieve "x" effect- is that we simply don't have the means to test for many of the compounds which may affect the aquarium habitat.

We get excited about the idea of tannins and humic stuff...Yet, like 90% of us have no clue how to even test for this stuff. Sure, there are tannin test kits...However, what do the numbers yielded by such a test even mean to us? Short of having an idea of the tannin levels in specific wild habitats, how do we interpret the data, anyways? (And, as we've discussed repeatedly- the color of our water in our aquariums provides no indication of the chemistry, right?)

At this point, it's really as much of an "art" as it is a "science", and more superficial observation- at least in our aquariums- is probably almost ("almost...") as useful as laboratory testing is in the wild. Even simply observing the effects upon our fishes caused by environmental changes, etc. is useful to some extent.

The more I think about our growing segment within the hobby, the more I realize that we are just at the very beginning. We've sort of "knocked on the door", acquainting ourselves with the types of materials we can use in our aquariums, with a developing understanding of their environmental impacts within them. And we are moving towards a period where we will undoubtedly try to work out the "recipes" for how to create specific environmental conditions within our aquariums using botanicals.

It's a logical progression, driven by the sheer number of hobbyists working with this stuff, and yearning to understand more than just the most superficial aspects. It will require more experimentation, and possibly even cooperation between pure science and the hobby. It's often a tricky, rather slow process, but this collaboration has always yielded impactful results. It's gradual. Yet, it will happen in time.

It's a very busy time. And it's hard to imagine a more exciting time to be in the aquarium hobby! 

Every day brings new possibilities. New ideas. New successes...and occasionally, failures. Yet, the more we learn- the more we apply to our work- the greater the possibility for unique rewards!

Stay progressive. Stay diligent. Stay engaged. Stay curious. Stay excited...

And Stay Wet.


Scott Fellman

Tannin Aquatics 

Scott Fellman
Scott Fellman


2 Responses

Scott Fellman
Scott Fellman

October 23, 2019

Hi There!

I have not personally tried this particular botanical; not aware of others who have. However, I suspect- gulp- that its okay, because we do see many hobbyists in Europe play with beech leaves…I know it’s a bit of a “stretch”, but I have a feeling that the nut cover should be fine if collected from non-polluted/pesticide-free areas and properly cleaned/prepared. There is, unfortunately- only one way to find out: Test it on an aquarium with live fishes. A scary prospect, I know- but really the only definitive way to answer that question. You may have to be the pioneer here! Are you up for it? Good luck!



October 22, 2019

Hi, I have been using leaves and cones in my aquariums for years, but inspired by your texts, I started looking for other botaniclas available in my climate zone (Central Europe), what do you think about beech nut cover (lat. cupula)? It is very decorative, but is it useful and safe? Have you used it?

Thanks for your research and sharing, best regards.

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