So the other day I was at wally world and was looking at kitty litter due to reading that refuguem mud is nothing but 100% clay, and that others have started using 100% clay kitty litter in place of the mud. While looking I found some other kitty litter that is advertised as 100% silica free zeolite sand, made from volcano rock. Anyone heard of this? Would it work in a reef system? The price is about the same as sand from a LFS but I am thinking that if it is even close to the zeolite carbon that they sell at stores that it might work better than regular sand for filtering out nitrates.