Recommended term of replacement, counted from the date of installation: PWC-670-01 NEO SENSE - mechanical filter - every 6 months PWC-670-02 INNO SENSE – mechanical-carbon filter - every 18 months PWC-670-03 RO membrane filter 20 GPD - every 20-24 months PWC-670-09 Hygienic filter – every 20-12 months The table shows only approximate, estimated series of exchanges not their warranty period. To ensure the most optimal filtration you may need to replace filters with greater frequency. Speed and quality of the filtration (the yield of water) is mainly dependent on water pressure, temperature and quality of the filtered water. Thus, reverse osmosis system always generate a recoil water. For EDELWASSER the ratio is provided 4:1 and in case of low pressure on the network even 6:1.