Soft water has hardness levels of -
Level of hardness is expressed in terms of milliequivalents per litre where one milliequivalent is equal to 50mg calcium carbonate in one litre of water. The level of hardness of hard water is equal to 3-6mEq/L or 150-300 mg/L. CLASSIFICATION LEVEL OF HARDNESS (mEq./L) LEVEL OF HARDNESS (mg/L) soft water <1 <50 moderately hard 1-3 50-150 hard water 3-6 150-300 very hard >6 >300 Park's Textbook of Preventive and Social Medicine, 25th edition, Page No.787
<50
100
150
>200
Environment and health