HCH-AS20 AQUASANA Filter Housing Description and Specs: No added chemicals to the water.Inactive scale crystal formations flow through water without sticking to heat exchanger.No electricity required.Low maintenance; one simple filter change every two years!Connection Size : 3/4 in NTPMaximum Flow : 7 gpmMinimum Pressure : 20 psiMaximum Pressure : 100 psiMinimum Temperature : 40 degree FMaximum Temperature : 100 degree FMaximum Hardness : 45 gpgMaximum Chlorine : 2.0 ppmInstall on Cold Water Lines Only