Note: Most parts are equipped with compression Tube Fittings Feature. –> –> Replacement filters for this system. Full 5 stage RO Filters Set 192300115180 Pre and post Filter Set: Sediment, GAC, CTO, inline Carbon 191729905484 Membrane 50 GPD 162005995211 Filter cartridges should be changed every 6-12 months under domestic conditions. Filter life varies and depends on the water source quality.