Please be sure to read the profile. Kurita Corporation - For drinking water during walks, use "filtered water," and you can switch to "raw water" for cleaning up after your pet uses the toilet. - Simply fill a commercially available drinking water bottle with tap water and set it in the main unit. Filter Replacement Guide When using 1 liter per day: Approximately 60 days (about 2 months) Replacement Cartridges x 6 Approximately 60 days (2 months) per cartridge Main unit plus one year's worth of cartridges Brand new, unused! ⚠ There is a slight dent in the box in the third photo. This does not affect the main unit inside! Please refrain from purchasing if you are concerned about home storage.