Drinkwell® 360 Cat Fountain - 3x Replacement Filters at a glance: 3-pack of replacement carbon filters for fresh, clean water Filters should be changed every 2 weeks Important: The fountain should be cleaned weekly with hot, soapy water to prevent cat hairs and other particles getting inside, which could affect the performance of the fountain. Furthermore, depending on how hard the water in your area is, the fountain (and maybe the pump) should be cleaned with vinegar and water. Instructions are enclosed. Please rinse the fountain carefully after descaling. Please use only clear water (no soap) to clean the filter. The filter should be changed approx. every 2 weeks. Please make sure that the water level in the reservoir is correct. The pump must not be allowed to run dry. If this happens, the guarantee is no longer valid.