<prompt> The hardness of drinking water should be?313-Jan6  <response>: ANSWER: C 1-3REF: Park 20th ed p. 636Drinking water should be moderately hard. Softening of drinking water Is recommended when the hardness exceeds 3 mEqLClassificationLevel of hardness mEqLSoft water 1 50 mglModerately hard1-3 50-150 mgl Hard water3-6 150-300 mglVery hard water 6 300 mgl 