My tank had brown stuff on the sand and glass wall of the tank, I think it should be algae, I on my lights 12 hours a day, and my NO3 is rather high, I'm trying hard to reduce the NO3, but it just keeps on going down and up again. So I would like to ask if I take out the sand to wash with fresh water, does it actually kill the algae on top of it? Or it will still be there? I really can't get a conch here at singapore. Any other sand algae eater recommand?