Eventually these materials cannot be removed with washing, rinsing, or backwashing. Use ProTeam® Filter Magic to restore filter efficency, compatible with all filters and sanitizers. Will not affect pool chemistry. Directions for use shown below. Instructions for ProTeam® Filter Magic & Haviland® Liquid Filter Cleaner Sand Filter: Quick clean - turn off inlets for all chemical feeders. While in backwash mode, add 6 - 16 ounces through the skimmer while backwashing. Deep clean - add 16 oz. per 2.5 gallons of water directly into the filter media. Let soak minimally 4 hours, then start pump with filter in the backwash position. Cartridge and Diatomaceous Filters: Quick clean - remove media from filter (cartridges or septum), place spray nozzle onto the product and spray from top to bottom. Allow to set for 5 minutes. Rinse thoroughly, replace. Deep clean, add 16 oz. per 2.5 gallons of fresh water. Place cartridge or septum into clean plastic or suitable container and soak minimally for 30 minutes. Rinse thoroughly and replace.