Grains per gallon is how your water hardness is measured. You will see the abbreviation for this (GPG) in relation to the maximum hardness removal quantity for each water softener. The higher the GPG, the upper the grain potential you will require. Exam the T&P Valve - A Temperature & https://drainclogged76532.tinyblogging.com/the-fact-about-water-heater-services-that-no-one-is-suggesting-73393619