Shedding some light on the color of darkness...

As I've mentioned many times here, we as a community are at a pretty remarkable place. We actually seek out and enjoy the tinted water! It wasn't really all that long ago when tinted water connoted "dirty", perhaps untended, even "dangerous" water conditions.

A lot of you ask about things that impact how long the water retains it's tint.

It's kind of a big deal for us- I get it! Many hobbyists who have perhaps added some catappa leaves, "blackwater extracts", or rooibos tea to their water contact me asking why the water doesn't stay tinted for more than a few days. Now, I'm flattered to be a sort of "clearing house" for this stuff, but I must confess, I don't have all the answers.

So, "Why doesn't my water stay tinted, Scott?"

Well, I admit I don't know. Well, not for certain, anyways!

I do, however, have some information, observations, and a bunch of ideas about this- any of which might be litter rely shot to pieces by someone with the proper scientific background. However, I can toss some of these seemingly uncoordinated facts out there to give us all some stuff to "chew on" as I offer my ideas up.

Now, perhaps it starts with the way we "administer" the color-producing tannins. 

Like, I personally think that utilizing leaves, bark, and seed pods is perhaps the best way to do this.I'm sure that you're hardly surprise, right? Well, it's NOT just because I sell these material for a living...It's because they are releasing tannins, humic substances, and other compounds into the water "full time" during their presence in the aquarium as they break down. A sort of "on-board" producer of these materials, with their own "half life" (for want of a better term!).

The continuous release of tint-producing compounds keeps things more-or-less constant. And, if you're part of the "school" which leaves your botanicals in your aquarium to completely break down, you're certainly getting maximum value out of them! And if you are continuously adding/replacing them with new ones as they completely or partially break down, you're actively replenishing and adding additional "tint-producing" capabilities to your system, right?

There is another way to "keep the tint" going in your tanks, and it's pretty easy. Now, those of you who know me and read my rambling or listen to "The Tint" podcast regularly know that I absolutely hate shortcuts and "hacks" I the aquarium hobby. I preach a long, patient game and letting stuff happen in its own time...

Nonetheless, there ARE some that you can employ that don't make you a complete loser, IMHO.😆

When you prepare your water for water changes, it's typically down a few days to a week in advance, so why not use this time to your advantage and "pre-tint" the water by steeping some leaves in it? Not only will it keep the "aesthetics" of your water ( can you believe we're even talking about "the aesthetics of water?") consistent (i.e.; tinted), it will already have humic substances and tannins dissolved into it, helping you keep a more stable system.

Obviously, you'd still check your pH and other parameters, but the addition of leaves to your replacement water is a great little hack that you should take advantage of.

It's also a really good way to get the "look" and some of the benefits of blackwater for your system from the outset, especially for those of you heathens that like the color of blackwater and despise all of the decomposing leaves and seed pods and stuff!

So, if you're just setting up a brand new aquarium, and have some water set aside for the tank, why not use the time while it's aging to "pre-tint" it a bit, so you can have a nice dark look from day one? It's also great if you're setting up a tank for an aquascaping contest or  other same-day club event that would make it advantageous to have a tinted tank immediately.

I must confess that yet another one of the more common questions we receive here from hobbyists is, "How can I get the tint in my tank more quickly?"- and this is definitely one way!

How many botanicals to use?

Well, that's the million dollar question.

Who knows?

It all gets back to the (IMHO) absurd "recommendations" that have been proffered by vendors over the years recommending using "x" number of leaves, for example, per gallon/liter of water. There are simply far, far too many variables- ranging from starting water chem to pH to alkalinity, and dozens of others- which can affect the "equation" and make specific numbers unreliable at best. 

You need to kind of go with your instinct. Go slowly. Evaluate the appearance of your water, the behaviors of the fishes...the pH, alkalinity, TDS, nitrate, phosphate, or other parameters that you like to test for.

It's really a matter of experimentation.

I'm a much bigger fan of "tinting" the water based on the materials in the aquarium. The botanicals will release their "contents" at a pace dictated by their environment. And, when they're "in situ", you have a sort of "on board" continuous release of tannins and mic substances based upon the decomposition rate of the materials you're using, the water chemistry, etc.

Here's another stupidly simple "hack" to get not only a "quick start" on tinting your water, but to help with the ongoing maintenance of the color with a minimal amount of intervention. I must admit, it's actually so basic that it's kind of like "cheating"- but hey, it's all about "hacking" today, right? 

What the hell is wrong with me? I'm pushing shortcuts? Yikes.

The inspiration for this "technique" (I'm kind of embarrassed to call it a "technique", really) is the numerous frantic posts from distraught hobbyists that you see on aquascaping/planted tank forums who freak the fuck out because they just set up their "natural" planted aquarium and the piece of wood they used is "...leaching tannins into the tank and coloring the water brown!" 


Okay, I shouldn't make fun of these hapless souls who just loose their shit and simply haven't figured out that tint is cool...but the beautiful takeaway here for us is that you can use your wood (oh, that totally came out wrong...) to your advantage as a botanical/blackwater aquarium fan. (that still sounded bad!)

When life gives you lemons (or in this case, tannins)...

Most aquatic woods like my personal fave, Red Mangrove, as well as Malaysian driftwood, "Spider Wood", Asian driftwood, and Mopani- impart significant amounts of tannins into the water, which is why those clear-water-loving weirdos (heh, heh) like to soak their wood pieces for weeks before setting up their tank, and use heavy amounts of activated carbon and other chemical filtration media indefinitely to remove as much of the tint-producing tannins as possible.

So, simply give your driftwood enough of a "presoak" (or not) as required to get it to sink and stay down on its own, and perhaps to leach out some initial impurities, like surface dirt, dust, etc.- and than place it in your tank, and let it release its tannin goodness into the water!

Sure, if it's too dark even for your sophisticated taste, you can always moderate it with some activated carbon or repetitive water changes until you get the "tint level" you like. And, as every "natural" aquarium fan knows, the wood will continue leaching tannins for a pretty long time...


Advantage: Us!

This is again a perfect  strategy for those who love the tinted water but perhaps dislike the idea of lots of leaves in their tank (WTF, guys?); or maybe those who just like the more durable, but "less-tannin-imparting" botanicals. Easy. Embarrassingly easy. And insanely obvious, too. Many of us simply didn't really consider it, because we got all caught up in using our leaves and botanicals to do the "heavy lifting", right?

Yet aquatic wood is the perfect "secret" that's literally been right in front of our collective eyes for a century or more of aquarium practice!

Use what ya'got, right?

The part where Scott bashes the shit out of the idea of using "blackwater extracts and Rooibos tea. This could get nasty.

If you haven't heard of it before, there is this stuff called Rooibos tea, which, in addition to bing kind of tasty, has been a favored "tint hack" of many hobbyists for years. Without getting into all of the boring details, Rooibos tea is derived from the Aspalathus linearis plant, also known as "Red Bush" in South Africa and other parts of the world. 

(Rooibos, Aspalathus linearis.  Image by R.Dahlgr- used under CC-BY S.A. 2.5)

It's been used by fish people for a long time as a sort of instant "blackwater extract", and has a lot going for it for this purpose, I suppose. Rooibos tea does not contain caffeine, and and has low levels of tannin compared to black or green tea. And, like catappa leaves and other botnaicals, it contains polyphenols, like flavones, flavanols, aspalathin, etc. 

Hobbyists will simply steep it in their aquariums and get the color that they want, and impart some of these substances into their tank water. I mean, it's an easy process. Of course, like any other thing you add to your aquarium, including leaves and botanicals, it's never a bad idea to know the impact of what you're adding. 

Like using botanicals, utilizing Rooibos tea bags in your aquarium requires some thinking, that's all. 

The things that I personally dislike about using tea or so-called "blackwater extracts" are that you are simply going for an effect, without getting to embrace the functional aesthetics imparted by adding leaves, seed pods, etc. to your aquarium as part of its physical structure, and that there is no real way to determine how much you need to add to achieve______.

Obviously, the same could be said of botanicals, but we're not utilizing botanicals simply to create brown water or specific pH parameters, etc.

Yet, with tea or commercial blackwater extracts, you sort of miss out on replicating a little slice of Nature in your aquarium. And of course, it's fine if your goal is just to color the water, I suppose. And I understand that some people, like fish breeders who need bare bottom tanks or whatever- like to condition water without all of the leaves and twigs and nuts we love.

And I don't think the stuff lasts all that long. I personally believe that the tinting tannins in "tea" are potentially taken up quickly by substrate materials, filter media, etc. And unless you're keeping tea bags in your tank on a continuous basis, you'll always see some "color loss" after some period of time.

Yes it works to impart some color and tannins. 

On the other hand, if you're trying to replicate the look and function (and maybe some of the parameters) of THIS:

You won't achieve it by using THIS:

It's simply another shortcut.

And look, I understand that we are all looking for the occasional shortcuts and easier ways to do stuff. And I realize that none of what we proffer here at Tannin is a n absolute science. It's an art at this point. There is no current way available to the hobby to test for "x" types or amounts of tannins (of which there are hundreds of types) in aquariums.  

I have not found a study thus far which analyzed wild habitats (say, Amazonia) for tannin concentrations and specific types, so we have no real model to go on.

The best we can do is create a reasonable facsimile of Nature.

We have to understand that there are limitations to the impacts of botanicals, tea, wood, etc. on water chemistry. Adding liter upon liter of "extract" to your aquarium will have minimal pH impact if your water is super hard. And of course, same with botanicals. This is a myth that we've worked hard to dispel. It tends to linger. And the "extract-pushing" crowd seems to not let go of it easily, IMHO!

When you're serious about trying to create more natural blackwater conditions, you really need an RO/DI unit to achieve "base water" with no carbonate hardness that's more "malleable" to environmental manipulation. Tea, twigs, leaves- none will do much unless you understand that.

I'm not trying to throw a wet blanket on any ideas we might have. I'm not feeling particularly defensive about using tea or other "extracts" because I sell botanical materials for a living. It's sort of apples and oranges, really.

And hey, the whole idea of utilizing concentrated extracts of stuff is something I've looked on with caution for a long time, and we've discussed here before. I'm an "equal opportunity critic"- I'll jump on our community for stuff we do, too! 🤬

Now, all of these ideas are okay to impart some color to your water. Some do more, as we've discussed ad nauseam. And none of them will work to full advantage if your aquarium is removing them as fast as you're imparting them into the water. SO, go easy on chemical filtration media liek carbon. I didn't say NOT to use them...Just don't use a ton of them!

What about plants?

Well, I have a theory. You absolutely can keep plants in blackwater aquariums. We've talked about this a million times. And interestingly, you can't always keep "blackwater conditions" (at least, color-wise) in planted aquairums! 

Tannin are interesting things. Think about this:

Tannins are known to bind up heavy metals and minerals. The roots of aquatic plants prefer to take up bound-up minerals and metals...So, another theory of mine is that heavily planted tanks do remove some of the visual "tint" (ie; the tannins) from the water via uptake from their roots. 

Make sense? Maybe?

Okay, I could go on and on all day throwing out all sorts of theories and unsubstantiated (via lab tests, anyways) ideas on this topic...But I think I gave you enough here to get the party started. I encourage you to do some homework. Ask tough questions of people who really understand the chemistry here. I think that there might be some good answers out there.

Let's throw some light on this rather "dark" subject with some good old fashioned research!

Stay curious. Stay observant. Stay resourceful. Stay patient. Stay creative...

And Stay Wet.


Scott Fellman

Tannin Aquatics 


Scott Fellman
Scott Fellman


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