The how's and why's of botanical prep- revisited...again!

Let's face it- one of the fundamental "skills" we have to learn as lovers of botanical-style aquariums is the preparation of the materials that we use. It's pretty much a given that we employ some prep before adding botanicals to our aquariums.

And it's an important practice which sets the stage for a successful natural aquarium experience. And we're all about seeing you succeed, so let's review this stuff again!

The idea is to get your dried botanical materials into a condition where they are both reasonably clean, and with their tissues saturated sufficiently to cause them to sink. This usually involves some simple, yet possibly time-consuming tasks, as we've all come to know.

There are basically three ways to prepare most botanical materials for use in the aquarium:

1) Boil them/steep them in boiling water

2) An overnight (or longer) soak in room temperature water

3)  A combination of both.

Always rinse any of our botanicals in clean fresh water before use, even after boiling or soaking. This will rinse away any loose dirt or organic material that has adhered to their surface tissues. Just sort of a "best practice", IMHO.

We start with boiling.

For the vast majority of botanicals, you'll need to boil them in a clean pot for at least 30-40 minutes; many "stubborn" ones (ie; really buoyant botanicals) may take more than an hour of continuous boiling! I'm thinking of Sterculia pods, Afzelia pods, and Carinaina pods here...

The boiling process not only saturates the tissues of many botanicals, it breaks them down a bit, and helps release any surface dirt that might be remaining (like dust, pollen, spider webs, etc.). The boiling serves the dual purpose of helping release pollutants and getting them to absorb water to sink. (No one likes a floating pod)

Consider that boiling water is used as a method of making water potable by killing microbes that may be present. Most nasty microbes "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)...However, 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.

A minimum of ten minutes of boiling is "golden", IMHO.  The boiling process not only saturates the tissues of many botanicals, it breaks them down a bit, and helps release any surface dirt that might be remaining (like dust, pollen, spider webs, etc.). The boiling serves the dual purpose of helping release pollutants and getting them to absorb water to sink. (No one likes a floating seed pod...well, maybe some of us do, but...)

And of course, we boil botanicals 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. 

Makes sense, right?

Boiling also serves to soften and saturate the tissues of the botanicals.

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! 


There is no "absolute" in this, either.

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.

If you remember your high school Botany, 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...

Rest assured, we are researching the use of more "fresh" tropical leaves in our systems; I'll get back to you on that one soon!

Are there variations on this preparation regimen?

Well, sure.

Many hobbyists rinse, then steep their leaves 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 materials like oak twigs often need a prolonged boil and soak to get them to sink reliably. It's a sort of "adapt as you go" thing, really.

And of course, I know many who simply "rinse and drop", and that works for them, too!

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. 

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 before adding your botanicals and leaves to your aquarium.

So, how long do you soak your botanicals?

The soak could be for an hour or two, or 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. 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.

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

Like so many things in our evolving "practice" of perfecting the blackwater, botanical-style 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 slow, taking the time, observing, tweaking, and evolving our "craft"- for the benefit of the entire aquarium community.

Stay diligent. Stay observant. Stay studious. Stay curious...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


Scott Fellman
Scott Fellman


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