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. This all depends on the condition of the water you are using in the humidifier as well as run speed. It is still recommended to clean your humidifier accordingly, based on the Manufacturer's Instructions.