World Health Organization thinks, water hardness wants measurable, interpose at 50-100mg/L, just be healthy water. The hardness of northward water is tall, mean life is 6 years briefer than southern. The hardness of water is too low, heart disease, diabetic sicken rate rises. Too hard or too soft water is gone against healthy.
World Health Organization thinks, formulary calcium, magnesian lowest content ought to be made clear in water standard, should be in 30mg/L above. 2006, 2007, the intake of Chinese calcium is 620mg/d only, average per capita is daily absorbed calcic amount often recommends a quantity under daily nutrition material, accordingly, water is a very good calcic replenishers. The sudden death that calcic, magnesian lack and cardiovascular disease cause has particular concern, show negative to close with the hardness of water.
But the hardness of water also cannot too tall, if exceed mark fiducial value, can cause the disease such as calculous disease, indigestion, the hardness of the area exceeds Hunan Province parcel badly mark, need bate.