Why do we boil stuff that we add to our aquariums in the first place?
Yeah, it's THE single most common question that we're asked here at Tannin, and has been the starting point for I-don't-know-how-many discussions over the years! So, let's touch on it again!
Why, Scott? Why do we boil this stuff?
Well, to begin with, 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)...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.
Ten minutes of boiling is "golden", IMHO. Of course, we boil for other reasons, as we'll touch on in a bit.
For one reason, 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.
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 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.
Then we boil.
Boiling also serves to soften botanicals.
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...
Are there variations on this theme?
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 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 by Cory Hopkins!). It does work, and it makes your house smell pretty nice, too!
It's not a perfect science- this leaf preparation "thing."
However, over the years, 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.
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.
The soak could be for an hour or two, or overnight...no 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.
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, 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.
In the end, preparation techniques for aquatic botanicals are as much about prevention as they are about "preparation." 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.
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.
The practice of botanical-style aquariums is still very much "open source"- we're all still writing the "best practices"- and everyone is invited to contribute!
Stay engaged. Stay fascinated. Stay observant. Stay excited. Stay involved...
And Stay Wet.