Reverse osmosis will remove salt, bacteria, viruses, protozoa, and cysts from the raw water, however, adding a UV Sterilizer is a good precautionary measure and an added level of protection. Many customers choose to install the UV sterilizers at the point of use, near a faucet or drinking water tap, as opposed to the output of the watermaker, since this protects from anything that may have contaminated the fresh water tanks.