One of my peices of drift wood that i cant see all the time it is in the back of the tank covered by onother peice of wood .Anyway i was cleaning the tank today and noticed it is compleatly white with this furry like stuff (covered in it ) almost looks like cottom floating in the water . it is attached to the drift wood though . freaking me out . i took the wood out of the tank but what is it ? that is my question? . and can i get rid of it by boiling it in aquarium salt ??. the tank is freshwater .