Introducing A.O. Smith S600 RO Water Purifiers. Our newest addition to the family of Sidestream RO which adapts the 2.0 Membrane Technology. Side Stream 2.0 technology enhances the market's highest purification water recovery rate: 2 Glass of pure water: 1 Glass Reject Water. The largest filtration capacity up to 600 Gallons per day (1.5 Liters/min) helps the process of taking water without interruption, the water is always fresh new generation in-line filter element, absolutely reducing the risk of water leakage. Typically installed under the sink (can also be a countertop). DOH/FDA Registered.