What Is Hard Water?

Hard water is water that contains a high concentration of dissolved minerals, mostly calcium and magnesium.

When water comes in contact with natural rock and sediment underground, minerals including calcium and magnesium are dissolved into the water. The more minerals in the water, the harder the water.

Over time, as hard water travels throughout your home, the minerals can form scale build-up inside your pipes and limit water flow in plumbing, hot water heaters and boilers. Hard water can also shorten the lives of equipment and appliances, including washing machines and dishwashers, and cause mineral deposits on your faucets and fixtures. All these issues can result in higher costs from additional maintenance charges and increased energy and water use.

You Might be Wondering, “Do I Have Hard Water?”

Luckily, hard water is easy to spot. You might have already noticed signs pointing to the presence of chronic hard water in your household.

  • Soap scum rings and stains on bathroom fixtures, sinks, tubs and showerhead
  • Newly washed clothes looking dingy or feeling scratchy
  • Noticeable spots on glassware, cutlery and dishware
  • Filmy residue on skin after bathing
  • An increased use of detergents in dishwashers and laundry machines

More than 85% of American homes have moderate to very hard water, view our Hard Water Map to see if you’re in a hard water area.

Testing for Hard Water

If you recognize signs of hard water in your home, testing for hard water is the best next step – and you can do it from your home! One of the simplest and least expensive ways to test for hard water is with a water hardness test strip, which can be purchased at a local hardware store. The strip measures the grains of hardness per gallon (i.e. the hardness of water relative to the amount of magnesium and calcium present), which establishes the level of hardness in your water.

Slightly hard water:                    1.0-3.5 grains/gal. 
Moderately hard water: 3.5-7.0 grains/gal. 
Hard water: 7.0-10.5 grains/gal. 
Very hard water: 10.5+ grains/gal. 

You Have Hard Water, Now What?

The solution to hard water is a water softener system. Plumbed into a home’s water supply, a water softener system is a mechanical appliance that uses resin beads and a process known as an ion (or cation) exchange to replace the calcium and magnesium in the water with sodium or potassium. The result is softened water throughout your home.