What Is Hard Water in Plumbing?

Hard water buildup
Aaron Stickley

The term "hard water" is used to describe fresh water supply that contains enough dissolved minerals in it to cause problems with plumbing systems and appliances that use water, as well as being unpleasant to users. What are the problems with hard water?  Among them:  

  • The minerals in hard water can clog pipes and restrict their water flow.
  • Hard water can cause film and scale to accumulate on ceramic tile and fixtures. 
  • The soap film is difficult to rinse away, leaving skin feeling dry. 
  • Shampoo residue on hair can affect its luster.
  • Scale deposits can shorten the life of water heaters.
  • Glasses and dishes may emerge fro the dishwater filmed and spotted. 
  • Hard water does not "suds" as well, leaving clothes looking unclean after washing. 
  • Harsh minerals in hard water cause excessive wear to clothing.
  • Hard water can affect the taste of beverages. 

So hard water is a common concern for many homeowners. Understanding exactly what hard water is and how it affects your plumbing can help you determine what, if anything, needs to be done about it.

What Is Hard Water?

Water that contains high mineral content is considered to be hard water. Although rainwater is pure when it falls from the sky, as it flows from the surface into aquifers, it absorbs mineral such calcium, manganese, and magnesium carbonate, and this absorption changes it from soft to hard water.

The amount of mineral content that water contains determines the hardness level of the water. Although the mineral content of household potable water is usually not harmful, it can be problematic and undesirable.

Water hardness is most often measured in grains of mineral per gallon (GPG). Water that tests at 3.5 GPG or above is considered hard water.

What Problems Does Hard Water Cause?

Hard water can be problematic because it reacts with cleaning products, creates buildup and can wear down fixtures and appliances quicker than soft water. The minerals in hard water may make cleaning products less effective, so it makes cleaning more difficult. The buildup of those minerals on dishes, clothing, fixtures, and even skin and hair can take their toll over time.

What Does It Do to Plumbing?

The buildup on tubs, shower, sinks and faucets caused by hard water are only part of the problem. The minerals in hard water also start to build up inside pipes, fixtures, and appliances over time. The buildup we don’t see can start to cause all sorts of plumbing problems, such as reduced water flow, clogs and increased stress on pipes and fixtures. The mineral deposits can also cause appliances to operate less efficiently and wear down faster. For example, a water heater has to heat all of the mineral scale buildup inside the tank, as well as the water. Overall, hard water results in less efficient plumbing and more repairs over time.

Testing For Hard Water

White scale buildup on plumbing fixtures is often a good indicator of the presence hard water. If you suspect that you have hard water, there is a low-tech way to test for hard water by shaking up a small amount of dish soap and water in a closed container.

Dish soap bubbles are a good indicator of water hardness because the minerals in the water react with the dish soap when they are present.

To pin down precisely how hard the water requires more testing or research. Start by calling your water provider, if applicable, to request the results of water testing they have done. You can also find a lab to test a water sample or have a company do an on-site test. Another option is to use a water hardness test strip that you hold under running water, then match to a color gauge. Test strips can be purchased at many home centers or on-line retailers. It’s a good idea to find out how hard the water is to determine how necessary or appropriate a water softener or similar solution really is.

Solutions For Hard Water

Water-conditioning products are available and can be used for dealing with mildly hard water.

However, the most complete and common solution for treating hard water is a whole-house water softener. Installing a water softener system in cases where the water tests above 3 GPG is often the most effective and efficient solution.