What does a water softener do?

A water softener removes calcium and magnesium—the minerals responsible for hard water. Depending on the system and water chemistry, it may also remove a specified amount of clear-water iron.

Reducing these aesthetic parameters helps prevent scale, soap scum, spotted glassware, stiff laundry, and mineral buildup in plumbing and appliances. A softener does not automatically remove every contaminant found in drinking water.