WATERCO FILTER MEDIA GLASS PEARLSGlass Pearl Filter Media Manufactured from pure glass, Glass Pearls are a new generation of filter media, capable of providing water of superior clarity. Its spherical shape results in low coefficient of friction, reducing backwash requirements, saving time, water and money. 3 micron filtration 20% less backwash water High purity Safe and smooth Time saving 0. 6mm to 0. 8mm in size