DetailsReplacement Cartridge for Goes Green 88 Shower Soft Water Filter. Uses 300 grams of pure KDF. KDF is far superior at removing chlorine than carbon in the shower. Help's enhance hair's pH balance, softens hair and skin. Helps preserve hair color. Prevents bacterial growth. For hot water in the shower, KDF is "hands down" the best filtration media available. Good for one year or 30,000 gallons, whichever comes first.