Reverse osmosis membranes forces water through a semi-permeable membrane, through an application of high pressure. They are typically used whenever salt removal or deionization is required. Reverse osmosis removes more than 97%-99% of the total dissolved solids along with organics, bacteria and other particulates.

Reverse Osmosis is particularly useful for areas, where water has excess amounts of Fluoride, Arsenic, Chlorine and other contaminants. Reverse Osmosis systems produce water at a much slower rate, compared to Ultrafiltration systems, but multiple reverse osmosis systems can be coupled with each other conveniently to increase the flow rate.