A world full of botanicals...

Experimentation is awesome! 

And it's just that- an experiment. And that means you likely don't kn ow exactly what the outcome-good or bad-will be. 

As more and more hobbyists push out into the natural, botanical method aquarium world, it's only proper that more and more of us experiment with different things. Being both a "power user" and vendor of botanical materials in my aquairums, I certainly consider myself fairly well-versed on a lot of this stuff (okay, as "well-versed" as one can be about adding "twigs and nuts" to his aquarium!). And, like you, I enjoy a good experiment or two, particularly when it comes to trying new botanical items for use in our aquariums!

I am constantly contacted by fellow hobbyists who've found "this seed pod" or leaf from a tree or bush in their yard, or while on vacation in Florida, or wherever. Sometimes, it's something they've seen offered by some other vendor, which we haven't discussed before here, and they'll ask me if the seed pods, roots, or leaves that they have procured are suitable for use in aquariums.

It leaves me in a sort of "damned if I do, damned if I don't" position- because Im apparently seen as an "authority" on some of this stuff, but the reality is that I can't possibly- and indeed, don't - know everything on it! Not even close.

And honestly, most of the time, I give the same answer if I have not used the item in question:

"I don't know.You need to research it and experiment with it."


I get it. Totally unsatisfying, huh? Especially from some "authority..."

Some might say that it's hardly the answer you'd expect from a guy who makes his living selling botanical items for use in aquariums, but it's the truth! And it's usually the most responsible answer I can give. Seriously, there are around 400,000 described plant species in the world, and an average of 2,000 new species are described each year! Who can possibly know everything about what could be safe to use in...an aquarium, for goodness sakes?

At the risk of sounding a lot like Dr. McCoy of "Star Trek" fame, I'm a fish geek, not a botanist, so understanding the physical/chemical/environmental impact of almost any terrestrial plant and its components on our tanks is "beyond my pay grade", as they say! I can only speak in general terms. To assert otherwise would simply be irresponsible on my part, and a huge disservice to the aquarium community.

When we started Tannin, the aquarium hobby already had a pretty good working knowledge of playing with some botanical items in aquatic environments. For example, Catappa (Indian Almond) leaves had been used for decades by fish people to impart tannins and humic substances into the water, as had guava and a few other leaves, and stuff like Alder cones.

Now, it just so happens that Catappa has been studied pretty extensively by science, and it's not only not harmful to fishes, but it's generally acknowledged that there are some beneficial substances contained in the leaves and bark, many of which are known generally to have potentially medicinal properties.

Of course, these "revelations" usually require us to think a bit...

Now, keep in mind that these substances are present to protect the tree from fungi, bacteria, and parasites, so it's always a bit of a leap when aquarists immediately extoll the virtues of them as fish remedies. I mean, they do apparently have some positive health impacts on fishes.

Flavonoids, such as Quercetin and Kaempferol, which are abundant in Catappa; substances which apparently have anti-inflammatory, and possibly even anti-cancer affects in humans, and anecdotally have been determined to be beneficial to fishes. I did come across a laboratory study from the Fisheries Ministry in Malaysia that determined catappa extract to be useful as a remedy and/or prophylactic for some fish diseases, so that study vindicated some of the "anecdotal" stuff, in my mind!

Of course, that does not give aquairum hobbyists or botanical vendors like me the "green light" to go crazy and assert that any given leaf or seed pod is useful for preventing fish diseases and such. 

In fact, the "medicinal" impact of botanicals is the thing you've likely noticed that we discuss the least around here over the past seven years- because it's the least important-and effective- reason for using them in the aquarium, IMHO. I mean, when my fishes contract diseases, I reach for real medications and treat them in a "hospital tank"- and you should, too.

You see tons of vaguely-worded articles online on the purported "medicinal" properties of Catappa, typically on sites that, well- sell the leaves. And typically, they're kind of vague and filled with all of the wonderful marketing hyperbole and claims (ie; bullshit) about their wonders that perpetuates all of the myths and suppositions that are unfortunately so abundant in the aquarium world about this stuff.

We've chosen steer clear of this kind of vagueness, and rather, choose to focus on their use as natural materials to foster a diverse ecology in the aquarium by recruiting microbial and fungal growth, and as a food resource for a variety of organisms along the food chain. We see botanical materials as a means to impart tannins, humic substances, and other organics from their tissues into the aquarium water, creating not only a visual "tint" in some instances, but impacting some of its environmental parameters as well (ph, for example).

Those things are typically not disputable, with the exception of to what extent they do this.

And of course, we're ultra-geeky about this. Yeah we geek out hard. 


One of the most amazing things about our practice of adding leaves, twigs, seed pods, snd 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 they 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-style 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 thateverything 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.

Proper identification is an important part of utilizing botanical materials in your aquarium. We've tried a lot over the years, believe me. And we've seen a fair number of them being given goofy names. In fact, almost every one of our "product names" are not "fictitious" names at all- we utilize the actual species name-tongue-twisting or linguistically ugly though it may be (I mean, "Dregea pods", are you fucking kidding me?) of the plant/tree/shrub from which the botanical comes from, and identify the geographic sourcing as well. I don't know what others who ply their trade in this hobby sector do, but we're over stupid names when we can ID properly.

So, disclaimers aside- there are a few general words of advice we have for you if you are going to collect your own stuff:

-Make sure that you are legally permitted to gather the materials that you're considering, and that you aren't trespassing on someone else's property while doing so.

-Make a positive identification of the botanicals that you're going to collect. A good "nature guide" or field guide to plants of your region can really help. And there's this thing called "Google" that might work well, too. Don't be lazy. 😆

-Confirm that the area you are collecting from is not sprayed with pesticides or subject to runoff from other toxic substances or pollutants. This is super important! If you're not sure, just don't grab them. It's simply not worth it, IMHO.

-If the plant has a popular name that starts with "Deadly _______ or "Poison_________"that's a pretty good fucking clue NOT to even consider using any part of it in an aquairum. Just sayin'...

- Collect the botanicals you're focusing on as naturally-fallen materials. This is particularly important with leaves, as we've discussed many times in this blog. When leaves fall naturally, they have consumed many of the sugars and other compounds which are not beneficial for our aquariums, and actually are more detrimental than helpful.

-Never collect anything from a tree or shrub which is protected, endangered, or otherwise restricted from being disturbed in your area. This is pretty obvious, but we'd be negligent if we didn't mention it here!

There are lots and lots of botanical materials which you can legally collect and safely utilize in your aquarium. Hobbyists have done this for many decades! It makes sense that you should seek out readily obtainable free materials for use in your tanks, if only just to supplement the more "exotic" materials which we offer. Not only is it a good way to save some money- it could get you into the "Great Outdoors" and maybe even create a new hobby for you! And it can be educating!

It's beyond just "collecting stuff." It's important to understand how these materials occur, what benefits they can offer, and how they play a role in the wild terrestrial-and aquatic- ecosystems of the world. 

And I've found out over the years that most trees and plants do have leaves, bark and seed pods which contain tannins humic substances, and other compounds which may have a desirable effect upon the aquarium environment. To what extent, may only be determined by careful laboratory analysis- something most of us are simply not equipped, educated, or prepared to do. The same goes for any other compounds these materials can impart into the water. 

And, some may prove toxic to aquatic and other animal life if consumed, steeped, or otherwise utilized in the aquarium. We have to do our homework.

So, no- I can't tell you if that cool seed pod you found on holiday in Ibiza or the root that you grabbed during your hiking trip in The Appalachians is going to nuke your Geophagus tank or not.

I can only tell you how we'd approach it: Try to research what you can (AGAIN-there's this crazy cool search engine on the "Information Superhighway" called  g-o-o-g-l-e, and they have all sorts of information you can look up!), and...beyond that, you could experiment with what you consider "expendable" (gulp- I cringe even saying that...) fishes in a reasonably controlled setting and see what happens...

Yeah, "experiment." Risk. Chance. It's not for everyone, but if you want to use "that seed pod" or leaf, you'll need to experiment for yourself to know for sure. 


Well, I can tell you that very single botanical item which we offer has been tested- and fairly extensively- in our own aquariums, and in those of some of our friends- with our own precious fishes before it's ever even been considered as something we'd offer for sale. It's the best way, IMHO.  We didn't just wake up one day and decide to create a business because we found some cool acorns in a tree down the street, ya know?

I've become shockingly conservative about what I use and offer for aquariums. I'm often approached by my suppliers over seas, who will tell me, "Hey, Scott, would you like some _______ pods for your customers?" After the initial excitement about how cool the damn thing looks, I hit the research, and perhaps I'll find out that the tree from which the pod comes is known to have poisonous bark or something...and I'll quickly slam the door on the idea, rationalizing that, if the bark is toxic, whatever the toxin my be could be found in other parts of the tree, including said seed pods. Not worth it, IMHO.

Hardly scientific, and possibly even a wildly incorrect assumption- but a pretty conservative approach if you're thinking about importing a bunch at great cost to use in fish tanks. Now, sure, sometimes I will take a chance and experiment with the pods or bark or whatever, but it can be many months, or in a couple of instances, a year or two of success with my own tanks before I'll consider offering the stuff for sale.

This is not a fast, "farm to table" kind of operation, lol.

We spent years playing with this stuff. And we love all of it.

And guess what? We've killed a few fishes- very few- along the way. But we have killed some. And, to be honest- it wasn't just because the botanicals we tested were somehow "poisonous"...it was usually because we pushed it, in terms of numbers of stuff added at once to a tank, using the materials without preparing, or just added too much too quickly.

It's worth repeating that, even with "safe" stuff, as we've discussed many times here- you can push too hard too fast, and create potentially tragic outcomes for your aquariums. 

You have to prep, add slowly, and observe. We say this over and over to the point where you're probably sick of hearing it- but we'll keep saying it. No matter what you use, where you obtain it from- or what anyone- even myself- says. Every aquarium, every fish, every situation is different, and the possible outcomes are always subject to lots of variables.

Natural materials can sometimes have unpredictable results. It's as simple as that. Anytime you add anything to your closed aquatic environment, "stuff" can happen. It's reality, as you know. Some fishes, like Apistos, are very sensitive to changes in their environment, and even with "safe" botanicals, you need to go slowly when adding them to an established aquarium. The botanical aquarium method is not completely risk free.

Now, after a while, like anything else, you sort of get a "feel" for what can and cannot work. You'll look at a seed pods or whatever and have a sort of hunch, test them, and be very pleasantly surprised. Other times, you'll be shocked that the seemingly innocuous leaves you just added to your test tank have the fishes gasping at the surface in minutes.

You just can't be sure until you test them yourself. 

Or, of course, you can get your botanical stuff from us or some other reputable source and have a little peace of mind, knowing that we at least use the stuff regularly in our own tanks after a lot of testing. I've even seen a few  Tannin "knock offs" pop up online lately, and that's cool. Check them out, for sure. Although I sometimes can't help but wonder, based on many of their "parallel" offerings, if all they did was try to source some of the stuff we offer and simply sell it at a lower price or whatever.

Like, we did the risky groundwork, and they figured it was all safe, lol.

Well, I suppose I can't blame them for adopting this "strategy."  It's cool, actually. Yet I can't help but wonder...The reality is that just dumping any leaf or pod from any source into your aquarium carries some risk to it, and that cool decorative gourd you saw at the craft store, for example, may or may not be coated, varnished, or otherwise chemically preserved with material that can easily wipe out your tank!

I've done that before, years ago, and I know at least a dozen hobbyists who've also tried that over the years, only to experience deadly consequences to save a few bucks. A "bargain" is no "bargain" when your precious fish are lying dead at the bottom of your tank.

I suppose it's in our hobbyist "DNA" to want to find shortcuts, "hacks", workarounds...whatever. And that's fine. If you accept the potential risks that go with it.

There's a reason why we offer what we do, and why we obtain our botanicals from the people we do. Going to the source overseas is challenging, expensive, and difficult. But it generally doesn't;t yield product which instantly kills fishes, either.

 It's why we aren't rolling out new things every single day. It takes time to source, test, and observe them in use. We test them extensively with our fishes before we'd ever think of making them available for yours. We know how they are collected and handled. We've gotten to know our global suppliers personally, which is awesome!  It took a number of years. We know what to expect from them.

And yeah, you might find find stuff cheaper, but I don't know for sure if you can find it safer, or backed up by lots of testing and free information. That's why our buddies at Blackwater UK and Betta Botanicals are also good "go to" sources for this kind of stuff...They are just as conservative as we are in that regard. Support suppliers who take the time to study what they sell.

That being said, if you're fortunate enough to have a nice oak tree or whatever near by, go for it- test those leaves and if they are not harmful, use them in your aquariums! Chances are, it's totally fine. This is the fun part of playing with botanicals! There is a lot of DIY potential here.

But you have to take the risk. 

(White Oak. Pic by Msact, used under CC BY-S.A. 3.0)

And it's worth it to me, when you can create an amazing, natural-looking-and-performing habitat for your fishes. You may just want to wait until someone else has done the groundwork, and that's totally cool, too.

So, if you see that cool seed pod, leaf, or piece of wood on your next hike, and think to yourself, "Gee, that would look killer in my tank!"- Go for it...but only after you weigh the risks, prepare the item for use, and test it carefully.

It's a very enjoyable, alluring, and fascinating part of the hobby, if you take the proper steps to minimize risk. 

It's beyond just "collecting stuff." It's important to understand how these materials occur, what benefits they can offer, and how they play a role in the wild terrestrial-and aquatic- ecosystems of the world. 

There's literally a whole world out there to explore..if you want to.

Stay adventurous. Stay curious. Stay bold. Stay excited....

And Stay Wet.


Scott Fellman

Tannin Aquatics 


Scott Fellman
Scott Fellman


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