Tropical Fish Forums

[Imani1978]

I had a piece of mopani driftwood in my freshwater tank for about a week (after soaking it to try and remove the tannins for a few days) and my tank water is so dark it's hard to see in it. I have removed the wood for now - soaking it in a separate bucket - and have put a new pouch of activated carbon in my filter. The tank is not quite cycled yet, so I don't want to do water changes. How long does it normally take for the carbon to absorb the tea color? Is there anything I can do other than wait it out?

Thanks for your help.

[Marcos Avila]

Well, theoretically the carbon would be capable of removing all the tannins with a single pass of your entire tank water through it, but since the clean water gets thrown back into the tank, mixed with the tainted water and recirculated, the clean up process takes many more "passes".

If everything's setup right and you have good circulation through the carbon (several times the tank volume per hour) you should see some significant improvement within a few hours...
_________________

Success with a fish/tank is measured in YEARS, not months or weeks...

[Imani1978]

Thanks Marcos. I put a power head in last night to circulate the water a bit better to get it over to the filter where the carbon is.
Guess that's the best I can do? How else could I get all the water to pass through the carbon?

[deborah_claro]

Soaking is good, but simply soaking this kind of wood will not remove enough of the substances which stain the water, even if you soak it for days. I suggest boiling this piece of wood for several hours, changing (and re-boiling) the water several times. Yes, you will use a bit of energy doing this but it's very effective for your problem.

As well, as the water circulates through your filter material and passes through the carbon, you might consider changing small amounts of water to move the stained water out even faster. Say, 10% of your total volume of water a day? This should be a safe amount and not interfere with your water chemistry.

_________________