The RO water filter system is a two-stage composite filter. The GAC filter uses a sediment-removing PP membrane and activated carbon block to reduce rust, sediment, and organic matter. The reverse osmosis filter uses a 0.0001 micron reverse osmosis membrane, a sediment-removing PP membrane, activated carbon block, and a pleated PET membrane for degumming to intercept TDS, salt, nitrate, PFAS, fluoride, and heavy metals.