Hey guys i got hooked on how nice pfs looks in aquariums, i want to use it know. I went to a local pool supply store and bought a 50lb bag of pfs sand. It came in a brown paper bag with no description the guy at the register didn't know much about it;he said it was 20 grit silica sand,its gray in color. i paid 10 bucks for it. Any input would be highly appreciated thanks.