Pool Filtration Crushed GlassMade from 100% recycled materials, glass filter media cuts down on backwash time as well as loss of pool water and chemicals. Filter Glass is environmentally sound and lasts 3 times longer than sand. You can use as much as 20% less media (by weight). In addition to needing less, Filter Glass acts as a stronger filter. It improves water clarity by 25% over sand, filtering particles down to 5 microns, unlike sand, which only filters particles as small