Baby tint tanks...The early days of the Blackwater/Botanical-Style Aquarium

I'm kind of curious about how everyone manages the "startup" and early days of their botanical-style, blackwater aquariums. It's a topic that we touch on, but I think that, with some many people getting onto the game, it's a great subject to keep an open dialogue about!

Our friend, Mike Tuccinardi, shared a pic of his latest blackwater tank, right out of the "incubator", settling in after its initial "botanical loading"- and the pic got me thinking about this process anew.


When you first start a brand new blackwater aquarium, there is a significant amount of botanical material placed in there. No doubt, you've been beaten over the head (quite literally, actually) to prepare everything by boiling/steeping/soaking before adding it to your aquarium.

Regardless, And that will often yield a very darkly-tinted tank right off the bat, or at least a few days after it was set up.

A lot of people ask me what I do with brand new tanks, in terms of "dealing" with the tinted water if it's "too much." That usually makes me smile, because I kind of know what they mean. You probably do, too: The water is so dark, you can't see from one end of the tank to another- that sort of thing!

Now, we're talking initially about aesthetics. Remember, just because the water is really dark doesn't mean the pH is 3.9 or something low like that. In fact, I've seen a number of tanks where we started out with neutral or mildly alkaline water, added some stuff, and the pH only varied from the water that came out of the tap by a couple of points.  Visual cues are not necessarily helpful in determining the alkalinity and pH of our tank water!

I've gotten a lot more into measuring TDS as opposed to just pH in my botanical tanks, and the insights and trends are yielding some interesting results.

For my source water, I use RO/DI water with a starting TDS reading of 0, and once it's added to the aquarium, you'll actually notice a bit of an increase in many cases. And this makes sense, I think. For example, my "V.2.0" office aquarium started with pure RO/DI water, with TDS of zero and pH of 6.70 out of the unit. When we added substrate, wood, leaves, and botanicals, the TDS rose to a high of 24, then dropped over the course of about 2-3 weeks to its "operating level" of about 20, which has trended down since. Now, we did do some water changes over that span of time, so it would only make sense, because you're "diluting" whatever is in the water affecting TDS. However, like everything else in aquarium keeping, consistency over time seems to drive results in a botanical-style aquarium as well.

And speaking of water changes, I'm personally very religious about a weekly 20% water change in my tanks. I'm not sure, quite honestly, how I arrived at 20% instead of the more popular 10% water change! I think it was one of those things that developed early on in my fish keeping years, and especially in my reef-keeping days when I was like. "If 10% a week is considered good, 20% must be better!!!" Of course, that's a sweeping generalization,  as there might be some situations (for example, with really touchy fishes) where you wouldn't want to change 20%, but it's one of those things that just sort of "works" for me, so it became a habit over the decades! 

The other thing I tend to do with new tinted tanks is...wait. Yeah, I don't rush anything. I give the tank at least two weeks to start settling in before I even think of cycling the tank. It's personal preference, but I find that the "shakedown period" give you the opportunity to really make sure that everything is good to go before you start on all of the exciting stuff that comes next.

One of the things I've noticed about my botanical, blackwater aquariums is that they "cycle" very quickly, and that over time, I've found nitrate accumulation to be almost nonexistent. Now, I don't know if that's something which you've noticed, too? I simply have never seen a nitrate accumulation more than 0.2mg/L!

Despite what I hypothesized over the years, when I really got into blackwater, botanical-style aquariums, I found little to no detectible nitrate, despite utilizing a lot of botanical material within the tank that was breaking down. I would have thought, at least on the surface, that there would be some detectible nitrate. Now, this is interesting, but I'm not the only one who has reported this. Many of you have. My hypothesis is that, yes, the material is breaking down, and contributing to the biological "load" of the system- but with an abundance of microorganisms living in, on, and among the botanical materials in the aquarium, and with regular frequent water changes, there is a very efficient processing of nutrients occurring. This is purely speculation on my part, but I think it's as good a guess as any, based on the repeated similar results I've achieved in every single blackwater/botanical-style aquarium I've kept for the last 7 or 8 years!

I'm sure that a more sophisticated explanation, revolving around the presence of "on- board carbon sources" and other biological processes is the reason. I think that we're sort of looking at a freshwater equivalent of a reef aquarium in many respects, where, instead of "live rock", a lot of the microbial population and biological processes occur within the botanicals themselves. Almost like "biopellets" in a reef tank, perhaps the botanicals are not only a carbon source for beneficial bacteria- they're also a sort of biological filtration "substrate" for them to colonize on. Again, speculative, and needing some more rigorous scientific investigation to verify one way or another, but it's been my working hypothesis for several years.

In my opinion, once they get through the initial startup phase, blackwater/botanical-style systems seem to run incredibly smoothly and in a very stable manner. If you adhere to a regular, yet simple maintenance schedule, obey the long-established common-sense "rules" of aquarium husbandry, and don't go crazy with radical overstocking or trying to speed up things too much by dumping tons of botanicals into your tank in a brief span of time, these systems run almost predictably, IMHO.

Yeah, you'll see stuff like decomposition and often, biofilms, the likes of which might horrify the uninitiated- but when these are understood to be a natural and indeed, beneficial part of the little ecosystem you've created, you'll further appreciate the stability of a well-managed blackwater/botanical-style aquarium!

The early weeks and months in the aquarium's life cycle really set the tone, in my opinion, for how the tank is likely to function over time. I am a big believer in stability, and deploying patience, using time-honored nutrient control/export techniques, and applying a healthy dose of observation and common sense all contribute to the ultimate stability and success of our blackwater/botanical-style aquariums just as they would to any other type of system.

The only real difference is that our water is a bit, well, "more colorful", right?

Let's hear your thoughts on the "startup" and early management of your botanical-influenced aquariums! 

Until next time...

Stay "tinted." Stay observant. Stay consistent.

And Stay Wet.


Scott Fellman

Tannin nAquaitcs 




Scott Fellman
Scott Fellman


2 Responses

Scott Fellman
Scott Fellman

May 03, 2017

Hi Eduard,

So glad to hear that your “journey to the dark side” is underway! Excellent to hear that you are doing so well! Tropica’s website is an outstanding resource, and is filled with great information! I think that it’s just so important to use that ONE thing we all need more of with our tanks: PATIENCE! Sounds like you have it and are benefitting from it! Keep up the good work!

Best of Luck!


Je suis heureux d’entendre que votre “voyage vers le côté obscur” est en cours! Excellente à entendre que tu le fais si bien! Le site Web de Tropica est une ressource exceptionnelle et est rempli d’excellentes informations! Je pense qu’il est si important d’utiliser cette chose dont nous avons tous besoin de plus avec nos réservoirs: PATIENCE! On dirait que vous l’avez et en profitez! Continuez votre bon travail!

Bonne chance!



May 02, 2017

Hello Scott !
I’ve stumbled upon your website – and articles, which I read religiously every day – reading the PFK magazine.
I was immediately charmed by this Blackwater concept and I said to myself that I had to dive in. So I ordered some botanicals – I don’t know if you get many orders from France , but in March it was me; BTW thank you for the careful packaging and the little extra – and I started a nano, a Fluval Flex 9 using sand, river stones , your Camarao bolsa, crypts, anubias, buces and mosses.
When I started my first freshwater tank back in 2013 I discovered the Tropica website and their start-up guide for the first 3 months.
So I’ve used it for this new project which is 1 month old and it’s running smoothly as silk , as it was the case with my 2 other tanks . The only "downside " is that the tint is very, very subtle at this moment, but the journey has just begun.
Best regards.

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