The Ultrapress replacement filters are rated for 300 cycles (150 L) of service life. Life is reduced when cleaning water with high levels of silt, sediment or tannins. Cartridge press time increases toward the end of cartridge life. When the press time reaches 25-30 seconds, the cartridge should be replaced. Even though the cycle time increases, the cartridge will continue to protect. It is recommended that the cartridge then be replaced at some point, despite any environmental concerns.