Originally Posted by SaltwaterNuB
No I was just asking Ingy. It would just be sand, that's what a lfs
I'm not sure what you're asking me. But there are 2 main types of sand used in tanks; coral based sands and rock based sands (PFS). Although they both have silcates in them, only the first can be exported to the water from the very soft mineral base while the second has the silcates bound very tightly in the mineral structure of very hard rocks (granite). Most common aquarium sand will cause a diatom bloom eventually because the diatoms can absorb the silicates. Then they die and are eaten by the CUC or corals and again become part of the structure (except a good portion gets exported thru your skimmer).
Diatoms have nothing to do with water quality. Changing your sand every few years will likely cause a new diatom bloom unless you switch to a harder sand.