Purify over 3,000 gallons of water from any fresh water source, then backwash the filter for continued use — no replacement filter needed. From technology used in medical dialysis equipment, the submicron hollow fiber membrane filter found in this revolutionary purifier uses a cluster of micro-fibrous tubes. When water is drawn through the membrane, it flows through the side walls of the micro-fibrous tubes without any noticeable pressure drop. Sediment, bacteria, protozoa, cysts, viruses and other contaminants are mechanically filtered out. This filtration product exceeds all applicable EPA recommendations. No pumping, no chemicals, no waiting, no worries.