Wood is natural,for the beauty of the fish tank,we need to clean the product after we get the product.soaking prior to putting in your tank or boiling it are the only way,It is best to add baking soda to boil,loop many times,which will accelerate the release of pigment.or,it is recommended to soak for several days until it does not turn reddish brown.each piece of tannin releases at a different time,some release tannin quickly and some slow down.tannin from driftwood are very good for the fish.A couple of months and the color would be gone anyway but it provides them a more natural environment "temporarily",tannin does not pose a safety problem to fish.