Question

what is standard hard water??​

Answer 1

Answer:

Water containing calcium carbonate at concentrations below 60 mg/l is generally considered as soft; 60–120 mg/l, moderately hard; 120–180 mg/l, hard; and more than 180 mg/l, very hard (McGowan, 2000).

Explanation:

Answer 2

Answer:

Water containing calcium carbonate at concentrations below 60 mg/l is generally considered as soft; 60-120 mg/l, moderately hard;120-180mg/l hard;and more than 180 mg/l, very hard (McGowan 2000).