PureGuardian FLTDC humidifier Demineralization Filter, Cartridge #1, is easy to use. It helps to prevent the release of minerals (white dust) into the air. It simply screws into the humidifier tank and will last approximately 1,000 hours or with the use of 260 gallons of water. This all depends on the condition of the water you are using in the humidifier. It is still recommended to clean your humidifier accordingly, based on the Manufacturer's Instructions. It is recommended to use with the PureGuardian Models H1510, H1610, H4610, H4810 and H8000B.