Question: is 20 grains hard water?
Answer: If your water has less than one grain of hardness, it is defined as “Soft.” Water with more than one grain of hardness is “Hard,” and can be Slightly Hard (1.0-3.5 gpg), Moderately Hard (3.5-7.0 gpg), Hard (7.0-10.5 gpg), and Very Hard (above 10.5 gpg).