The process: The "How and Why?" of Botanical Preparation...

Some 7 years into the adventure that is Tannin Aquatics, and the world of botanical method aquariums seems to be exploding! There are more hobbyists creating these types of aquariums than ever before, more vendors offering botanical materials, and more information!

And of course, there is lingering confusion and even mis-information. The kind of stuff that can confuse any newcomer to our little sector, and actually prevent many people from succeeding with these types of aquariums. There is a surprisingly large amount of bad information out there on some of the most basic processes we employ.

To this end, I think it's time for me to do a periodic review of some of the fundamentals of our practice and processes. Let's start with one of the most basic- the art and science of botanical preparation.

"Preparation required..."

Words you've heard us utter again and again; precautions you've seen us advise you to take. You see it on our packaging, hear it discussed on "The Tint" podcast, and read about it in articles we publish here and elsewhere. Yet, there appears to be some confusion about what exactly we mean by "preparation."

Yeah, it's not a secret that, before you throw those seed pods and leaves into your aquarium, you need to do some preparation.


And why are we talking about this again?

Well, seriously, I still receive about 3-4 emails every single week from customers of ours (and from others, apparently!) asking what to do with botanicals after  they receive them...So, it's obvious to me that some people just aren't seeing this stuff, hearing it, reading our instructional cards, social media posts, etc., or not getting advice from the people they purchased their leaves, or whatever from. (Isn't EBay great! What a resource for serious hobbyists!)




I know, it's starting to sound a bit repetitive...

However, with the world botanical-style aquariums growing at an exponential rate, and more and more hobbyists entering into the fray- many of whom are enamored by the beautiful aesthetics of these tanks, it's important-well, actually essential- to revisit this stuff again and again.

And really, because most of the new vendors into our market space simply appropriate much of the information we put out to help the community, and use it to push their products, let's at least give those lazy-ass motherfuckers something useful to share (and since they're not bothering to provide this information, themselves...)!

Okay, mini-hate-rant over. For now.

"So, you're really into boiling and steeping botanical, huh?

Yes. I am. That's my thing.

"Why do you do that?"

Consider that boiling water is used as a method of making water potable by killing microbes that may be present. Most nasty microbes essentially "check out" at temperatures greater than 60 °C (140 °F). For a high percentage of microbes, if water is maintained at 70 °C (158 °F) for ten minutes, many organisms are killed, but some are more resistant to heat and require one minute at the boiling point of water. (FYI the boiling point of water is 100 °C, or 212 °F)...But for the most part, most of the nasty bacteria that we don't want in either our tanks or our stomachs are eliminated by this simple process.

So, wouldn't it make sense to boil, or at least steep, our botanicals before we dump them into our aquariums?

Yeah, it would.

Ten minutes of boiling is "golden" to assure a "good kill", IMHO. Of course, we boil for other reasons, too-as we'll touch on in a bit.

The most important reason that we boil botanicals is to kill any possible microorganisms which might be present on them. Leaves, seed pods, etc. have been exposed to rain and dust and all sorts of things in the natural environment which, in the confines of an aquarium, could  introduce unwanted organisms and contribute to the degradation of the water quality.

And, the surfaces and textures of many botanical items, such as leaves and seed pods lend themselves to retaining dirt, soot, dust, and other atmospheric pollutants that, although quite likely harmless in the grand scheme of things, are not stuff you want to start our with in your tank!

So, we give all of our botanicals a good rinse with fresh water.

Then we boil them.

Boiling also serves to soften botanicals. This is important to do for a number of reasons...

Well, the most obvious to us is thats it helps saturate the tissues of the botanicals and make them sink. I mean, who wants a bunch of floating seed pods and leaves in their aquairum? Wait, don't tempt me here...

If you remember your high school Botany (I actually do!), leaves, for example, are surprisingly complex structures, with multiple layers designed to reject pollutants, facilitate gas exchange, drive photosynthesis, and store sugars for the benefit of the plant on which they're found. As such, it's important to get them to release some of the materials which might be bund up in the epidermis (outer layers) of the leaf.  As we get deeper into the structure of a leaf, we find the mesophyll, a layer of tissue in which much of photosynthesis takes place.



We use only dried leaves in our botanical style aquariums, because these leaves from deciduous trees, which naturally fall off the trees in seasons of inclement weather, have lost most of their chlorophyll and sugars contained within the leaf structures. This is important, because having these compounds present, as in living leaves, contributes excessively to the bioload of the aquarium when submerged...

Personally, I feel that we have enough bioload going into our tanks, so why add to it by using freshly-fallen leaves with their sugars and such still largely present, right? I mean, it's definitely something worth experimenting with in controlled circumstances, but for most of us botanical method aquarium geeks, naturally fallen, dried leaves are the way to go.

The analogs to processes which occur in wild aquatic habitats are incredible, and part of the reason why, if left to "do their thing", that botanical method aquariums run in such a stable manner. 

When leaves are placed into the water, they release some of the remaining "solutes" (substances which dissolve in liquids- in this instance, sugars, carbohydrates, tannins, etc.) in the leaf tissues rather quickly. Interestingly, this "leaching" is known by science to be more of an artifact of lab work (or, in our case, aquarium work!) which utilizes dried leaves, as opposed to fresh ones.

The most important part of the process of utilizing botanicals in leaves in aquariums is analogous to the natural process of decomposition, which ecologists call the "conditioning phase", during which microbial colonization on the leaf takes place. Bacteria begin to consume some of the tissues of the leaf- at least, softening it up a bit and making it more palatable to fungi.

This is, IMHO, the most important part of the process. It's the "main event"- the part which we as hobbyists embrace, because it leads to the development of a large population of organisms which, in addition to processing and exporting nutrients, also serve as supplemental food for our fishes!

The botanical material is broken down into various products utilized by a variety of other life forms. The particles are then distributed throughout the aquairum by the currents and are available for consumption by a variety of organisms which comprise aquatic food webs.

Six primary breakdown products are considered in the decomposition process: bacterial, fungal and shredder biomass; dissolved organic matter; fine-particulate organic matter; and inorganic mineralization products such as CO2, NH4+ and PO43-

This is exactly what happens in Nature. And that's why we prepare our botanicals- because "prepared" botanical materials literally "kick start" the ecology of the aquarium! 

An interesting fact: In tropical streams, a high decomposition rate has been related to high fungal activity...these organisms accomplish a LOT!

So, yeah, that's perhaps the biggest reason why we prepare leaves for aquarium use!

Are there variations on this prep theme?

Well, sure. Of course! 

Many hobbyists rinse, then steep their leaves in boiling water, rather than a prolonged boil, for the simple fact that exposure to the newly-boiled water will accomplish the potential "kill" of unwanted organisms, which at the same time softening the leaves by permeating the outer tissues. This way, not only will the "softened" leaves "go to work" right away, releasing the beneficial tannins and humic substances bound up in their tissues, they will sink, too! 

And of course, I know many who simply "rinse and drop", and that works for them, too! And, I have even played with "microwave boiling" some stuff (an idea forwarded on to me a few years back by aquascaper Cory Hopkins). It does work, and it makes your house smell pretty nice, too!

It's not a perfect science- this leaf preparation "thing."

And I admit, I've changed some of my approaches over the years...I'd be foolish not to. 

Of course, the fundamental idea behind preparation of botanicals hasn't really changed too much. And the underlying rationale hasn't changed, either. 

Leaf preparation has evolved quite a bit, actually! Many aquarists have developed simple approaches to leaf prep that work with a high degree of reliability. Now, there are some leaves, such as Magnolia, which take a longer time to saturate and sink because of their thick, waxy cuticle layer. And there are others, like Loquat, which can be undeniably "crispy", yet when steeped begin to soften and work just fine.

There is no 100% guaranteed way to perfectly prep every botanical or leaf the same way every single time.

You have to be flexible and adaptable.

So why do we soak after boiling?

Well, it's really a personal preference thing.I suppose one could say that I'm excessively conservative, really.  Do you HAVE to?

No. However....

I feel that it releases any remaining pollutants and undesirable organics that might have been bound up in the leaf tissues and released by boiling, which is certainly arguable, but is also, IMHO, a valid point. And since we're a company dedicated to giving our customers the best possible outcomes- we recommend being conservative and employing the post-boil soak.

The soak could be for a half an hour, an hour or two, or even real "science" to it. Some aquarists would argue that you're wasting all of those valuable tannins and humic substances when you soak the leaves overnight after boiling. I call total bullshit on that. My response has always been that you might lose some, but since the leaves have a "lifespan" of weeks, even months, and since you'll see tangible results from them (i.e.; tinting of the water) for much of this "operational lifespan", an overnight soak is no big deal in the grand scheme of things.

So don't stress over that, okay?

Do what's most comfortable for you- and okay for your fishes.

When it comes to to other botanicals, such as seed pods, the preparation is very similar. Again, most seed pods have tougher exterior features, and require prolonged boiling and soaking periods to release any surface dirt and contaminants, and to saturate their tissues to get them to sink when submerged! 


And quite simply, each botanical item "behaves" just a bit differently, and many will require slight variations on the theme of "boil and soak", some testing your patience as they may require multiple "boils" or prolonged soaking in order to get them to saturate and sink.

Yeah, some of those damn things can be a pain! 

However, I think the effort is worthwhile.

Now, sure, I hear tons of arguments which essentially state that "...these are natural materials, and that in Nature, stuff doesn't get boiled and soaked before it falls into a stream or river."

Well, damn, how can I argue with that?

The only counterargument I have is that these are open systems, with far more water volume and throughput than our tanks, right? Nature might have more efficient, evolved systems to handle some forms of nutrient excesses and even pollution. It's a delicate balance, of course.

I believe that some steps to prepare botanicals before adding them to our aquariums is not only beneficial because it helps to cleanse them of some of the aforementioned pollutants- the practice itself creates "ritual" in our speciality, which in turn, helps to create "best practices" which can benefit all who play with these types of aquariums.


In the end, preparation techniques for botanical materials are as much about prevention as they are about "preparation."

To summarize- by taking the time to properly prepare your botanical additions for use in the aquarium, you're doing all that you can to exclude unwanted bacteria and microorganisms, surface pollutants, excess of sugars and other unwelcome compounds, etc. from entering into your aquarium. 

And, most important, you're readying your botanical materials to support the ecology of the aquarium.

Like so many things in our evolving "practice" of perfecting the blackwater, botanical-method aquarium, developing, testing, and following some basic "protocols" is never a bad thing. And understanding some of the "hows and whys" of the process- and the reasons for embracing it-will hopefully instill into our community the necessity- and pleasures- of going slowly, taking the time, observing, tweaking, and evolving our "craft"- for the benefit of the entire aquarium community.

The practice of botanical-method aquariums is still very much "open source"- we're all still writing the "best practices"- and everyone is invited to contribute! 

That's part of the fun, isn't it?

It is.

Stay engaged. Stay fascinated. Stay observant. Stay excited. Stay involved...

And Stay Wet.


Scott Fellman

Tannin Aquatics


Scott Fellman
Scott Fellman


Leave a comment