Fastest way to remove tannins

[Arthur11]

Tannin is one of the toxic substances harmful to fish. So you should know how to remove tannins from aquarium water: Activated charcoal can be used. It helps to remove the yellowish to brownish color in the aquarium and restore the pH level of the water. Alternatively, Seachem products such as Purigen and Renew can be used to counteract the discolouration effects of tannins.

Tannins cause the brownish or yellowish tint of aquarium water. The discoloration of water is not a significant problem – it will not harm the fish. However, tannins are usually acidic. They will slowly lower the pH of the water, which can ultimately harm the fish.