Blackwater basics, and a late week "*&^%$-slap to fellow catappa vendors!

Oh, it's time for more Tint Hacks!" Well...sort

Seriously, as the blackwater/botanical movement evolves, we're getting a lot more questions about some of the functional and practical aspects of maintaining one of these cool tanks, and it's a good time to review a few things! Like, really, really basic things. And that is SO COOL!

I can't tell you how many "Thank You!" and "That was awesome!" responses I received from readers of yesterday's blog- so I now realize that, as our world is so rapidly evolving, with many newcomers entering into the fray daily- it makes just sense to keep revisiting some of the seemingly "basic stuff" as our experience and knowledge of the art and science of botanical-style/blackwater aquariums evolves.

One question that we receive a lot is how "capable" botanicals (particularly the beloved Catappa leaves) are at reducing pH. Regrettably, there has been much misconception about their capabilities, for which I place the blame...squarely on the shoulders of the "bulk Catappa" vendors on places like E-bay and such (yeah, there are a number of good ones, but many are simply slinging leaves) and provide little in the way of detailed (and accurate) information for hobbyists to work with. Calling their asses out. Yes, I'm being mean spirited and a bit boorish, because it's not all of them...yet it's a lot of them, judging by the number of questions we receive that start with, "I bought some Catappa from this guy on E-bay, and..."

We need to do better as an industry in educating.

Oh, and it's 4:54 AM here in Los Angeles as I write this blog, and I haven't had my first cup of coffee yet. :)

(Excuse registered.)

The ability of the tannins and humic substances in the Catappa leaves to influence the pH is largely predicated upon the starting pH and general hardness of your water. It's one of the things I have written about before, because a lot of the aforementioned  (what I call..) "low end" catappa vendors just sort of say fluffy generic stuff like, "Lowers ph and makes fish breed..." which only perpetuates the myth that these leaves can do it all in every situation, IMHO.

They can't.

The reality is that, if your water is hard and alkaline to begin with, the use of catappa will likely only lower the pH a very, very small amount...if at all. Of course, the water will visually tint and the beneficial (for fish health) humic substances will be imparted into the water (as long as you're not using activated carbon or other chemical filtration media, which will take out this stuff).

That being said, you can get a great visual tint even in hard, alkaline water. However, tint is not an indication of pH level. It simply is indicative of the amount of tannins in the water. One dip of your electronic pH meter into your blackwater tank will tell all . (Yes, an electronic pH meter is like "essential equipment" for us "Tinters", IMHO).

Personally, I start with straight RO/DI water, and then the leaves and other botanicals will have far more influence on the pH.  I know that there are water chemistry freaks and others that will rain hell-fire upon me for suggesting straight-up RO/DO water, for fear of the dreaded "pH crash" or whatever, but the reality is that, in my personal experience with blackwater tanks (a couple of decades now) I've never, ever had this happen.  What prevents this in my tanks? Typically, it's the use of sand and rock, which I personally (and yeah, it's all anecdotal) believe provide some slight buffering.

Oh, and common sense stocking, feeding, and maintenance. I've never really gotten my tanks lower than pH 6.2 with substrates present, so that's where I kind of got my theory. Now, those of you using the low pH planted tank substrates and such, with little or no mineral content, would be far, far more likely to see much lower pH levels. Even then, in the experiments I conducted, I couldn't get my water below, ever.

And it just sat there.

Now, I'm not telling you to just do what I do and dump stuff in and use straight-up RO/DI and walk away and "Instant Rio Negro" happens in your suburban living room. That would be as ignorant and stupid as the claims some of those "low end" guys make.  Damn, that sounds so freaking nasty of me, huh? (Hey, it's how I feel...let them write a daily blog, blah, blah..."Shut up Fellman" lol). You need to monitor pH and general hardness. You need to understand your source water's ph and hardness. This is part of the game. It's not hard, but you need to do it. You can't take my word, or the guy on the "Acid Water Forum" (oh, that would be a cool one, huh?) as the world's foremost authority on this stuff.

People have had weird shit happen in lower pH tanks. Part of the game is knowing that you're working in a world that has been lightly traveled over the years, and there is still a lot of scary mystery stuff in people's heads.You just have to DO and STUDY and TEST YOUR WATER. Like, weekly. Get a "baseline" for your tank's "operating parameters" and such. Don't make assumptions. It's easy to simply observe, record, and analyze. and it's kind of fun...and you just might make great contributions to our tinted and murky blackwater world, so why not do it?

As far as how long the "visual tint" produced by leaves, botanicals, etc. will last, there is no real firm answer I can give, as there are so many variables involved...And I don't think that the rate and amount of tannin-release from leaves and botanical materials in water has ever been scientifically studied to determine this (hmm.....if I had the resources, how cool a study would THAT be to fund? Hello, Kickstarter? ). 

I look at my early product descriptions for our website and actually cringe when I realize I wrote "starting recommendations" for how many leaves to add to a tank...I fully intend to edit those parts of the descriptions, because they were based solely on extrapolating the numbers from various successful tanks I have run over the years, and are probably of little real help to most people. I mean, it's like that "low-end-vendor" crap I just railed on. (I think I just &^*%$-slapped myself!) Again, it perhaps gives a starting basis to think about, but the reality is that every aquarium is different, and you need to determine what works for YOU.

As much as we'd love it- there is no "recipe" or "plug-and-play" steps to achieving perfect blackwater parameters in YOUR aquarium. We have general guidelines, tempered with the need for YOU to test and kind of figure out what works for your system. I'd be a complete (insert favorite expletive here) if I gave you some kind of recipe. We have "best practices" (constantly evolving) and our own power of observation. That' what makes this realm so exciting and fun to play with. We're all still evolving this hobby specialty together!

In my experience, typically leaves will last on the order of 3-4 weeks, during which time they will release whatever tannins and other compounds are present in their tissues. Likely the most "useful" period is the first 2-3 weeks. Again, it's more of an "art" than a science, but this has been my personal experience with them. How often you need to add or replace leaves to keep the parameters and visual tint of your water going consistently is really something that you will need to determine for yourself.

"Oh, for @#$%^&* sake, that all you've got to say about this?"


Okay, a "hack" (gulp) as promised:

One "hack" to keep the tint going consistently in your tank is to "pre-tint" and "condition" (another aquarium-hobby "hijacked" term that makes me vomit, BTW) your source water for water exchanges ahead of time. Simply steep a few leaves in your water storage containers, so it has a sort of "visual tint" that you like and pH that you're targeting...helping things stay more consistent at every change... Again, monitor the pH, and you will know that if you use the same water to prep for your tank in the same sized container that 4 medium sized catappa leaves gives you the color and pH you like, you've sort of got that "recipe" for YOUR specific needs...

This is all very much a dance. Every tank- every user- has different needs and expects different outcomes. Every aquarium has its own "cadence" by which it operates and evolves. Learn yours. Assist it, if necessary. But, by all means, study it. And know that you CAN "customize" your experience by putting in the work to figure it out. Totally worth it. 

Stay experimental. Stay engaged. Stay observant. Stay cautious.Stay out of trouble!

And Stay Wet.


Scott Fellman

Tannin Aquatics 

Scott Fellman
Scott Fellman


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