Is it bad for one’s health to drink either hard water or soft water?

Hard water (excess minerals in the water), is found in 85% of American homes. It is the most common water quality problem reported by American consumers. Hard water is not unhealthy; it is safe for drinking, cooking, and other household uses. However, it can be a colossal nuisance because it can do damage in the following ways: 1) shortening the life span of plumbing and appliances that use water (the tea kettle, coffee maker, etc.) ; 2) leaving white/chalky deposits on tubs, sinks, and pots and pans; 3) causing dingy laundry; and 4) leaving a film of the body and on hair.
 
Softening water with a sodium-based ion exchange water softener increases the sodium content of the water. If you have health concerns about increasing your sodium intake, note that many water softeners have a bypass feature that allows you to bypass the cold water in the kitchen so that you can use unsoftened water for drinking and cooking. Another compromise is to soften only the hot water coming into your home, and use only cold water for drinking and cooking.
 
Source(s):
Virginia Cooperative Extension - “Water, when the well’s dry, we know the worth of water” by Linda Burcham