Question: is 7 grains considered hard water?
Answer: Typically, water that contains less than 1 grain per gallon is considered soft, while water with 1 to 3.5 grains per gallon is slightly hard. ... The grains per gallon for moderately hard, hard and very hard water are, respectively, 3.5 to 7, 7 to 10.5 and over 10.5.