Reverse osmosis (RO) systems use multi-stage filtration and an RO membrane to significantly reduce dissolved salts (TDS), hardness-forming ions, many dissolved impurities and heavy metals. Depending on the model, additional stages may include remineralization, carbon post-filtration or other treatment. For well water or microbiologically questionable sources, the system should be configured according to a water analysis and supplemented with appropriate pretreatment or UV disinfection when required.
