Use—and even reuse—this efficient alternative to heavy sand or glass filter media for your pool’s filtration system. A 1.1 lb Krystal Clear Fiber Ball Filtration Media bag does the job of 40 lb of silica sand. Plus, our fiber balls are machine washable, with no messy backwashing. Inexpensive, lightweight alternative to heavy sand or glass filter media. Reusable and machine washable: No messy backwashing. Compatible with all INTEX sand filter pumps. Contents: 1 Bag = 1.1 lbs (18 kg) equals 40 lb (18 kg) of silica sand