This means they are generally placed at a tap, usually in the kitchen. A separate faucet is often installed to bypass the RO unit so treated water is used only for cooking and drinking. A bypass increases the life of prefilters, postfilters and the membrane, making treatment more economical. Membrane selection, an important characteristic of RO systems affecting performance, is based on various water characteristics such as acidity, hardness, total dissolved solids and chlorine content. A water analysis provides information on your water's characteristics.
Water pressure influences an RO system's performance.
The higher the water pressure, the better the rejection of pollutants and the more purified the water. Typical water pressure in most homes may be adequate for RO treatment. Booster pumps can be added if it is not. Doubling the net pressure across a membrane more than doubles the output flow rate of treated water. Keep in mind home water pressures vary significantly, which changes the efficiency of the unit.