Pick out the false statement pertaining to water treatment.

A. Aeration of water is effective in CO2 removal

B. The zeolite water softening process reduces the hardness of water by not more than 50%

C. Sodium sulphate or sodium carbonate do not cause hardness in water

D. Water with pH value less than 7, is acidic

Please do not use chat terms. Example: avoid using "grt" instead of "great".