# will tannins block the light enough to kill plants?



## BreakingBread (Sep 1, 2012)

My driftwood has been leaching for weeks, and i do water changes every other day, i'm about to order plenty of plants for a decent start but im concerned that the tannins from the driftwood will block the plants light by the second day. The water will turn very brown. the tank has 300gallons. I dont mind changing 25% every day of whatever method makes a smoother transition for the plants. Any thoughts would be appreciated. I have a custom led setup that i can crank up, this will be a hightech setup. 
Thanks all.


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## Rivercats (Aug 15, 2012)

When I dirted my tank I had some heavy tannin leechng, besides the WC's I added a large amount of Purgen to my Fluval FX5 and it really helped suck the tannins out. Carbon will work too but I'm not a fan of carbon use in a planted tank. Another thing, if the DW is able to be removed, you can take it out and boil it. I've never done it but alot of people swear that boiling it will take alot of the tannins out. I just read you don't have plants in there yet, I have a 220g dirted and I did 100% WC's for 7 days before planting and then added the Purgen and it really helped. But I think in your case I'd try to boiling since some DW can leech tannins for a long time.


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## AVN (Oct 3, 2012)

Tannic acid will only block a tiny percentage of light, because of it's tan-brown pigments. Not enough to stunt plant growth.

EDIT: Tannin acid is a naturally occurring plant protein that makes your water slightly acidic. It lowers the PH of your water, which MAY be detrimental to some plant growth. However, it will not directly be the cause of plant death or growth stunts.

I have also found mixed results as to whether Tannic acid can be beneficial or detrimental to certain plants. As the Tannin binds and removes metal ions from the water.


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## tomfromstlouis (Apr 2, 2012)

I have not experienced what I would call heavy amounts of leeching from my driftwood and have been growing plants okay. I simply soaked the wood for two weeks, changed 90% of the water and went to a couple of weekly 50% WC after that. I have one canister filtering through peat moss too. I would call the water a weak tea color, not "brown", and my 8 hours of light is probably still too much. 

Here is a recent shot through 6' of water:


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## AVN (Oct 3, 2012)

My tank is browner than that, and all my plants and fish are happy. Fish are breeding in my water, which is two-three times as brown as that.


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## BreakingBread (Sep 1, 2012)

This gives me hope! thanks guys


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## WestHaven (Jun 30, 2012)

I actually like the tan-brown color caused by tannins. It looks more natural.


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