These membranes range from 24 to 150 gallons per day and all fit in a standard residential RO membrane housing.  24 through 100 gpd membranes are manufactured in the USA by Filmtec. In systems that include ion exchange/deionization, a higher rejection membrane will extend the useful lifespan of the DI resin.

           Factory Specifications - Residential Membranes

¹ Membrane capacity is expressed in gallons per day, or gpd.  Low pressure or cold water will result in the membrane producing fewer gallons per day.

² The pressures and temperatures shown here should not be considered "ideal" or "maximums."  They are simply the standards supplied to the membrane by the manufacturer for purposes of testing membrane performance.

³ The term "rejection" refers to the proportion of TDS in the feedwater which the membrane does not allow to pass into the purified water stream.  Although related, it does not provide any information concerning the ratio of concentrate (a.k.a. waste water) to permeate (a.k.a. RO water).