i read about them and was thinking of adding it to the prawn tank do these really clear the water up ? i have 6 pieces of drift wood in a 55 gal tank and i do weekly water changes but the water still seems ot get cloudy is this because of the drft wood leeching ? all i have are 5 indian prawns and 10 guppies and 5 baby rosenbergi's i check the water its all safe levels