June 22, 2016

Keeping it clean while keeping "the tint."

A question we receive frequently around here is, "How do you keep your water 'clean', in addition to water changes, yet still keep the 'tint' you rave about some much?"

The answer is coming. But first, let's consider a couple of things.

Do you use activated carbon in your aquarium?

Long championed by those who love crystal clear water without any colors or visible impurities, activated carbon does a remarkable job removing organic compounds, acids, and in particular, two substances which accumulate in water- phenols (decidedly nasty substances), and tannins, which....whoah. Wait a minute.

We like our tannins around here, right?

So, why would we want to use carbon?

Well, it's a bit of a conundrum, isn't it? We want some of the other benefits of carbon without what we in the "tinting" world would consider to be a drawback- the superior ability that carbon demonstrates for removing tannins! Activated carbon can increase pH slightly when new, but this is typically a temporary effect. And of course, there are times in aquarium keeping when the immediate need to improve water quality outweighs the "setback" of removing the tannins which tint our water (for example, in an emergency situation where you've overdosed the tank with something, experienced cloudy water, etc., etc.)

Other media, such as Seachem Purigen, also remove tannins, but tend not to affect the ph of the water...so if you like a lower pH environment but are not a fan of the tint (gasp!), you'd be advised to use this media in place of activated carbon. It does eventually become exhausted, and may be regenerated if desired. Better.

Still, that's not totally comforting to us lovers of "the tint"; I mean, that stuff is good. REALLY good! As you may know, we utilized both of these media during our recent "clear water" trial in our office aquarium, and are both happy and sad to report that they kept the water as "colorless as glass" during our (agonizing) two month test run!

What to do? "What do YOU use, Fellman?"

Worry not. Here's the answer.

Seachem makes another wonderful filter media which can do the trick. It's an "organic scavenger resin" called "Renew."

"Huh, what's THAT", you ask?

"Organic scavenger resins" are polymers (resins) that react with specific by-products, impurities, or excess reagents produced in a reaction. In other words, they remove some things and not others. Perfect! Renew will not aggressively remove tannins and humic acid. It will remove organics and particulates and will also help control ammonia, nitrates, and phosphates. Being less aggressive than carbon, it's well suited for tinted tanks and planted aquaria, because it leaves the color bodies and trace elements required by plants present! It is effective for about 30 days, after which time it needs replacement.

Ohh, interesting!

This material won't raise the pH of our water like carbon can. Renew allows for control of organics without total depletion, as with more aggressive media such as carbon, etc. The "dose" is 250 mL for each 120–160 L (30–40 US gallons) of aquarium capacity. For a tinted aquarium, it's the only media you need to use on a continuous basis, from my point of view. It almost looks like a an aquarium substrate to me!

So, the answer to the burning question, "What's the most useful chemical filtration media in a tannin-stained aquarium?" in my humble opinion, is Seachem Renew. I love the stuff, and I've been using it for some time. The next question is, "Will you be selling the stuff?" And the answer is, "We sure will!" Look for it on the site now as our "media of choice" for the tinted aquarium!

So, go ahead and add those leaves, throw in that wood, and a few seed pods while you're at it...and know that your tank is protected from excessive accumulation of organics by this efficient organic scavenger resin!

It's often interesting to look beyond the immediately obvious choices, and then find things that really work for us. Use of an organic scavenger resin is the ideal compromise, in my opinion, between necessary utility and aesthetic considerations!

Stay focused. Stay thoughtful. Stay open-minded.

And Stay Wet.

Scott Fellman

Tannin Aquatics

Scott Fellman

Author

8 Responses

Scott Fellman

August 25, 2021

Hi Ned, I usually put the Renew or other media in a fine meshed filter bag and let the water flow through it. Renew is a bit too fine to use loosely. The old “filter wool” and carbon idea probably wouldn’t work with that stuff, lol.

Scott

Ned

August 06, 2021

Hi Scott,

Awesome article and a lot of great info since I’m new to tannins and planted tanks (used to keep African Cichlids). I was wondering what other filter media you use besides the Seachem Renew, a biological media and do you use filter floss or something around those lines? Asking cause I have a new planted betta tank with botanicals in it and I wanted to see what you’re using.

Josh

November 29, 2018

Killer article, very simple and well written!

I’m new to the blackwater setup, and was in dire need of a new filter media. Renew is in the mail now.

Thanks a million.

Scott Fellman

April 13, 2018

Hi Darryl,

I do use carbon, and although we don’t have a test for specific tannins, if you have significant material in the aquarium, I am of the opinion that you won’t remove all of them from the water. Most botanicals will continue to release tannins and other compounds as long as they are in the water and breaking down.

Hope this helps!

Scott

Darryl Smith

April 12, 2018

P.S. Question for your (if you are able to answer it), in your previous comment you said you could even use carbon if there was enough tannin producing agents present. If you use things like carbon or chemi pure green/purigen and your water is crystal clear or nearly crystal clear does this mean that all of the tannin producing benefits from the driftwood, pods and leaves, have been stripped out of the water? In essence, if your water is not tinted or slightly tinted does it still contain the tannic acids and water softening/ph lowering effects? Thanks

Darryl Smith

April 12, 2018

Thanks Scott for the reply. I had been using either chemi pure green or purigen over the last year or so and I was looking for a good alternative filtration media to use in my tanks. All are heavily planted and contain drift wood and catappa leaves. I wanted to start leaving in the benefits the tannic acids provide and I am quite certain that chemi pure and purigen was removing these as my tanks never really stayed tinted for very long. Thanks again I will be switching to Renew.

Scott Fellman

April 12, 2018

Hi Darryl,

Thanks for stopping by the Tannin Aquatics site and checking out our blog!

I would consider Renew a chemical filtration media. My understanding is that Renew is essentially a substitute for carbon, in that it is somewhat less aggressive at pulling out organics from the water, including stuff like tannins. I’ve used it extensively over the years in blackwater systems and have been able to keep ’em nice and tinted, while realizing negligible (read: undetectable) phosphate and nitrate.

Quite honestly, if you have enough tint-producing materials in your tank, you can even use carbon- it’s really a matter of preference…Yeah, I LOVE Seachem “Matrix” carbon, too…Probably sound like a Seachem “Fan Boy”, but I like everything I’ve used from their line! And I do use PolyFIlter and on occasion, the “nano” Chemipure “pods” passively in my filter chambers in my tanks…the Chemipure can really remove the tint, though, being comprised of an organic scavenger resin and carbon! Good stuff all!

Hope this helps!

Tint on!

Regards,

Scott

Darryl Smith

April 12, 2018

Thanks Scott for the information regarding Seachem’s Renew. I hope to be placing an order from your website soon as I have begun keeping/breeding apistogramma agasizzii fire reds. I am currently using a lot of driftwood and catappa leaves in my tanks and have been using seachem purigen and or sometimes Boyd’s chemi pure green. Chemi pure green is advertised for the planted tank but as you highlighted in your comments most filter media such as purigen or chemi pure green will keep your water crystal clear but they also remove all of the tannic acid produced by the driftwood and leaves. You are correct in the look of Renew, it does look like gravel and/or small version of Seachem’s matrix or denitrate. Is renew a chemical media or more biological filter media? Thanks and it was nice to see your post as I was searching on the internet for a filter media that was tannin friendly but would also help to remove other organic matter while leaving in the tannin benefits.