There must be SOMETHING in the water, right?

We've played with the idea of using botanicals for imparting humic substances and tannins into the water in our aquaria for the purpose of altering environmental conditions for some time now, haven't we?

And of course, sometimes, these environmental conditions create outcomes that we might not have expected. Hoped for perhaps, but not expected.

It happened yet again...a breathless phone call from a customer who recently switched over to a botanical-style, blackwater aquarium, only to have her little Boraras, which she'd had for over a year, suddenly start spawning!


Now sure, it could just have been that they finally were of spawning age, or that the temperature in her tank changed one night, or... number of a dozen possible factors. She felt it was "something in the water" released by the botanicals that she added not too long ago (in her case, Selatan Catappa Bark). I can't say with any high degree of certainty that this was, indeed, the catalyst for the results she is enjoying.

However, I hear these stories from hobbyists fairly often...In fact, likely too often to think that it's merely a complete coincidence, or a set of unrelated events and random factors.

Yeah, we hear this stuff a lot.

Actually, all the time. Like, regularly.

What we're seeing more and more in botanical-stye, blackwater aquariums are reports of "spontaneous" spawnings of all sorts of different fishes associated with these types of conditions.

Often, it's fishes that the aquarist had for a while, perhaps with little effort put into spawning them, and then it just sort of "happened." For others, it is perhaps expected- maybe the ultimate goal as it relates to said species...but was just taking a long time!

The "common denominator" in all of the reports we receive are that the fishes are displaying better color, vigor, and overall health after being recently exposed to the more "physiologically appropriate" conditions of a blackwater aquarium. Now, this is by no means us stating that blackwater tanks are somehow magical, and possess the ability to make every fish spontaneously thrive and spawn.

That's just complete B.S., and I won't ever make or support those kinds of assertions.

Rather, it's more of an affirmation that fishes from specialized environments- even those which might be several generations captive-bred, can always benefit from being "repatriated" to the conditions under which they have evolved for eons.

I know that there are those who will adamantly state that this is not necessary or true, but I just have this really hard time accepting the argument that fishes from say, soft, acidic blackwater are somehow "better off" in hard, alkaline "tap water" conditions...after only a few generations in captivity. Have we somehow "changed" the physiology or physiological needs of the fish, which evolved over millions of years, in a few decades?

I'm not buying that argument! 

"Acclimated" to the water parameters that work for US? Sure...Helped them to adapt to conditions different than those under which they evolved? Perhaps. However, have we "changed" their physiological requirements/preferences for certain conditions?

Nah. I'm not buying that. 

Now, I could be totally wrong, but I'm not listening (I'm not irrationally stubborn or anything...LOL)

We can all relate to this.

Look, this L.A. boy, who's lived all of his life in warm temps CAN adapt to living in frigid Antartica, if I'm given the proper clothes, housing, etc. I could even start a family there. Yet, does this mean that I've somehow evolved to thrive in these conditions?

No, it means I'm adaptable. Capable in surviving in conditions different than those under which I have "evolved" under...

Okay, not a perfect example, however...

Seriously, I think there is a lot to be said for the potential benefits of humic substances for fishes- and indeed, much research has been done in this area already by science. Still, much is yet to be fully understood, but suffice it to say, there are a variety of health benefits ascribed to humic substances found in blackwater habitats, and the "superficial", yet numerous observations we've collectively made thus far seem to confirm this!

What advantages do they give us when we're trying to breed fishes from these habitats?

We're still learning this stuff, aren't we?

Now, I am equally fascinated by the possible benefits of these conditions for fry. In other words, not only the chemical conditions (i.e; pH, levels of tannins/humic substances, etc.), but the possibility that the biofilms which botanicals and leaves "recruit" will serve as an excellent natural source of food- supplemental or otherwise- for many fish fry.

Biofilms and the organisms which are found with them are consumed by a number of species as adults, so it goes without saying that, if they're available to fry, they might also be a possible source of nutrition.

Which leads me to wonder...

Could a botanically-"stocked" aquarium, complete with perhaps a deep leaf litter bed and/or lots of botanicals, "doing their thing", serve as a sort of "nursery" for fry of fishes which are accustomed to blackwater conditions?

I think so!

So, perhaps a version of the fry-rearing tank that's a bit more than the typical bare-bottomed, hyper-maintained nursery tanks we tend to use so often- might be a good thing to experiment with? I mean, sure, for commercial breeding, it probably would be a challenge...but for the hobbyist working with just a few species...could this be a great way to provide some supplemental/primary feeding? A sort of "botanical refugium" for fry? 

I think there is precedent.

I mean, what hobbyist hasn't had one of those planted "jungle" tanks over the years, where you'd just sort of "stumble" on fry from time to time in the "canopy" of plants? I mean, same idea, right? Natural foods...and protection?

I think that we might see some of this as more and more hobbyists experiment with botanical-style brackish tanks, too! A lot of potential discoveries- even breakthroughs- are possible! 

None of this stuff is completely mind-blowingly revolutionary. But it is evolutionary...a sort of possible progression in thinking. It's not really "rocket science" ("Fill tank with water. Add leaves and let them decompose. Watch biofilms accumulate...Add fish fry.")

I mean, it's likely not THAT easy, but it's not a difficult concept, either. Much research needs to be done. 

And all of this continues to link up with our old friend, patience. Patience is simply fundamental in the botanical-style aquarium world, and it can truly make the difference between success and failure.

Observation and  attempting to ascertain what's going on in your tank "real time" are key practices that we need to embrace in order to determine what, if any benefits botanicals are bringing to the fight.

Yes, I know, we talk a lot about patience here, especially in the context of working with our botanical-style blackwater aquariums. We've pretty much "force-fed" you the philosophy of not rushing the evolution of your aquarium, of hanging on during the initial breakdown of the botanicals, not freaking out when the biofilms appear...patience.

Embracing the process.

What goes hand-in-hand with patience is the concept of...well, how do I put it eloquently...leaving "well enough alone"- not messing with stuff. In the context of trying to get fishes to breed, this is always a bit of a challenge, isn't it?

Yeah, just not intervening in your aquarium when no intervention is really necessary is not easy for many aspiring breeders. I mean, sure, it's important to take action in your aquarium when something looks like it's about to "go South", as they say- but the reality is that good things in an aquarium happen slowly, and if things seem to be moving on positive arc, you need not "prod" them any further. 

I think this is one of the most underrated mindsets we can take as aquarium hobbyists. Now, mind you- I'm not telling you to take a laissez-faire attitude about managing your aquariums. However, what I am suggesting is that pausing to contemplate what will happen if you intervene is sometimes more beneficial than just "jumping in" and taking some action without considering the long-term implications of it. It's one thing to be "decisive"- quite another to be "overreactive!"

And of course, it's important to think about what the things you're observing actually mean...

When that fish starts hiding in the corner, one of the first words out of our mouths is "disease!" Well, IS that what's happening, or is the fish merely "chilling out", or perhaps startled, or even- guarding a clutch of eggs? Your first action shouldn't be to net the fish out, tearing up the aquascape and generally freaking out every fish in the process, right?

I mean, consider what could have precipitated the behavior before springing into action that might have worse consequences for your aquarium and the inhabitants. Maybe it's literally just a "passing behavior" for the fish. Like any living creature, fishes will occasionally engage in unexpected behaviors, which are not necessarily indicative of an illness or problem.

How do you know what to do- or if you should do something? You observe. It's what you already do a lot of anyways, right? Observe your tank constantly, which will give you a sort of "baseline" for its normal function, for the fishes' behaviors, the operational "norms" of the equipment, the environmental parameters, etc. Just because a blog or a book or a friend tells you that "x" is "not right" doesn't necessarily mean that it isn't in your aquarium.

Sure, if you have ammonia, something is not right. Duh. However, if the otherwise healthy Cryptocoryne is growing more slowly in your tank than what "the books" say, it may not be a "problem", right? There could be a lot of different reasons- many of which are not remotely associated with "problems." The key to understanding when stuff is going wrong is to know what it's like when things are going right in your tank. Observe. Constantly.

Document your tank and its operation.

Keep a notebook, take pics, whatever it takes. One of the things we love to see are the tank "progression pics" that you share with us on Facebook. You can see how the botanicals begin to break down, how the water "tints", how the fish color up, etc. It's part of the observation process, which is part of the understanding process, which is part of how you determine if you need to leave stuff alone, or spring into decisive action to circumvent a potential disaster!

It's that simple. You probably already do this to some extent. However, it's easy to forget when its "your babies", right? Online aquarium forums are filled with frantic questions from members about any number of "problems" happening in their aquariums, a good percentage of which are nothing to worry about. You see many of these hobbyists describe "adding 100 mg of _______ the next day, but nothing changed..." (probably because nothing was wrong in the first place!). Now, sure, sometimes there ARE significant problems that we freak out about, and should jump on-but we have to "pick our battles", don't we? Otherwise, every time we see something slightly different in our tank we'd be reaching for the medication, the net, adding another gadget (a total reefer move, BTW), etc.

Let nature take its course on some things.


For example, you have biofilms appearing on your botanicals.

Understand what they actually are, and why they appear, and that they are normal- and suddenly, those yucky-looking strands of goo don't seem quite so menacing. When you see pics from the Amazon showing biofilms and algae growth all over the place, you start to understand that, just like the brown water and decomposing leaves, they're an important, integral, and totally normal part of the habitat we replicate.

Learn what "normal" is.

Realize that Nature will plot a course with minimal intervention on our part. Sure, when long-term health or even the enjoyment of your system is tarnished by some of these things, intervention is necessary. Excessive algae, for example, is indicative of a an excess nutrient issue, and can be managed with simple adjustments. However, for so many things, the best "course of action" is to let nature do as she's done for eons...

Embrace nature.

Understand how our closed systems are still little "microcosms", subject to the rules laid down by the Universe. Realize that sometimes- more often than you might think- it's a good idea to "leave well enough alone!"

When those fishes "spontaneously" spawn, realize it's likely a combination of factors, assisted along with patience, and making the right finesse moves at the right time...

Yeah, there MUST be SOMETHING in the water...

Stay excited. Stay curious. Stay kind to yourself. Stay thoughtful. Stay observant. Stay patient...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


Scott Fellman
Scott Fellman


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