Pure ?n Clean? is the ULTIMATE professional grade cartridge and DE filter cleaner.?? This fast action multipurpose cleaner removes calcium, minerals, dirt, oils, and scale.? Its? deep penetrating action renews and improves cartridge and D.E. filter efficiency and flow rate.? Recommended for use in all cartridge and DE grid filters.Pure ?n Clean? also cleans soiled surfaces on outdoor patio furniture, pool equipment, acrylic spas, boats, and much more!