Originally Posted by GrndHog
I was told today by a guy at my LFS
that you have to be careful on using southdown because sometimes there is an over abundance of silica in the sand. He said that alge loves to attatch its self to it and thrives off of it.
Does this make sense or is there any truth to it?
, silica does not have any affect on algae growth. Only silicates
fuel algae growth as diatoms and dinoflagelates use it in the growth of cell walls. Silica cannot be transformed into silicates in a marine tank.
The only small concern with silica sand is the sharp edges it has which can cut into the delicate animals that live in the sand. Sugar or "oolitic" sand does not have the same problem.