Can AquaTru filter hard water?

AquaTru is intended for water with hardness below 10 gpg (grain per gallon). If the hardness is higher, lime scale will build up on the membrane inside the Reverse Osmosis filter. Scale build up will plug the RO filter and increase filtering time requiring more frequent descaling maintenance and RO filter replacement. We do not recommend that AquaTru is used with water in excess of 10 gpg hardness, unless the water is softened prior to filtering in AquaTru, or unless you regularly complete our descaling maintenance. See What is descaling? and How do I descale my AquaTru Classic or AquaTru Classic Smart? to learn more