Hardness
Hard water is not hazardous to health, but it is considered a secondary or aesthetic contaminant.
Clothes laundered in hard water may look dingy and feel harsh and scratchy. Dishes and glasses may be spotted when dry. Hard water may cause a film on glass shower doors, shower walls, bathtubs, sinks, faucets, etc. Hair washed in hard water may feel sticky and look dull. Water flow may be reduced by deposits in pipes.
The amount of hardness minerals in water affects the amount of soap and detergent necessary for cleaning. Some synthetic detergents are less effective in hard water because the active ingredient is partially inactivated by hardness, even though it stays dissolved. Bathing with soap in hard water leaves a film of sticky soap film on the skin. The film may prevent removal of soil and bacteria. Soap film interferes with the return of skin to its normal, slightly acid condition, and may lead to dry, itchy skin. Soap film on hair may make it dull, lifeless and difficult to manage.
Hard water also contributes to inefficient and costly operation of water-using appliances such as water heaters. Heated hard water forms a scale of calcium and magnesium minerals that can contribute to the inefficient operation or failure of water-using appliances. Pipes can become clogged with scale that reduces water flow and ultimately requires pipe replacement.
The recommended treatment for hard water is to install a water softener.