64oz.org may earn commission for purchases made through the links posted on this page.

Harmful Effects of Hard Water

by Peter Lombardi

Quality Specialist, Consultant

> 4 min read


Harmful Effects of Hard Water

Many consumers believe the water that enters their homes from the public water supply is pure. However, the water that comes through your faucets can contain harmful substances. Water that contains high levels of calcium and magnesium is known as hard water. Although unlikely, consuming high levels of these minerals can harm your health.

There is also the potential for hard water to cause damage to your pipework, surfaces, clothing, household surfaces, and skin. Telltale hard water signs include limescale buildup in your coffee pot, iron, and other appliances, faded or gray-looking clothing, a film on your countertops or around your sinks, shower, and bathtub, and the inability to lather soap or laundry detergent. 

If you are unsure if you have hard water, you can ask your municipality for a water report and to run a hard water test. This can help you determine if you need a water softener to eliminate hard water’s harmful effects.

HERE ARE OTHER QUESTIONS THAT YOU MIGHT HAVE ABOUT WATER:

Scum Buildup on Your Surfaces

One of the most obvious signs your home has a hard water supply is the buildup of soap scum on your surfaces. Soap contains sodium salt, which dissolves easily in soft water. When in contact with hard water, the sodium salt binds with the high calcium and mineral concentrations. Instead of a generous lather, you end up with a curd-like substance that forms a residue on your surfaces. 

Soap scum is a breeding ground for bacteria, mold, and mildew, which can adversely affect your health. It is also challenging to remove without harsh cleaning chemicals.

Hard Water Causes Dry Skin

Although you may find soap scum on your surfaces frustrating, you may have deeper concerns about hard water harmful effects on your skin and hair. Hard water makes it more difficult to rinse soap from your skin, leaving behind residue that can cause irritation. This situation can be particularly aggravating if you already suffer from skin conditions such as eczema or psoriasis. 

Even without soap, the minerals present in hard water can attach to your skin, affecting your skin's moisture balance and pH levels. This means you could experience itchy, dull-looking skin that feels dry to the touch.


"Hard water makes it more difficult to rinse soap from your skin, leaving behind residue that can cause irritation." 


Damage to Pipes and Appliances

Hard water can cause severe damage to your pipes and domestic appliances, resulting in potentially expensive repairs and replacements. When hard water flows through your piping system, excess magnesium and calcium can attach to the pipes’ surfaces. 

When this process repeatedly occurs over time, the deposits become larger, reducing water flow through your system. A drop in water pressure means you need to run your faucet for longer when washing, cleaning dishes, or showering.

The magnesium and calcium deposits eventually break off from your pipes when they become too large, possibly causing damage and taking small pieces of piping material with them as they travel. 

High concentrations of minerals can also reach your household appliances. The calcium and magnesium deposits lodge in your washing machine, dishwasher, and any other device that requires a water supply. 

These machines have to work harder, causing excessive wear and tear to their components. You may notice an increase in your energy bills, that machines are not working as well as usual, or that you need to replace parts more often.

Damage to Laundry

When washing laundry in hard water, you may find clothing, towels, and bed linen appear faded and rough. The hard water harmful effects occur when calcium and mineral deposits inhibit the laundry detergents’ ability to form a lather. 

Because the minerals bind with fabrics, limit stain removal and can cause whites to appear gray and colors to fade more quickly than expected.

Concerns About Health Risks

Drinking hard water is unlikely to cause any serious health risks; however, excess mineral consumption can be an issue for some people. 

High levels of calcium could be a cause of constipation or increase the risk of heart disease. If you consume excess magnesium, you might feel nauseous, experience vomiting, or even have trouble breathing. If you experience respiratory distress, immediately seek medical attention.

How to Test for Hard Water at Home

The United State Geological Survey (USGS) offers a water hardness map that displays the water hardness level in every state. This resource can give you a good indication of the types of mineral present in your water and whether your water supply could potentially damage your home or body. 

However, if you need further information about whether your county’s water supply contains high mineral levels, there is a simple test that you can perform at home. Pour ½ a cup of tap water into a clean sealable bottle and add 5-6 drops of dishwashing detergent. Close the cap and shake vigorously for 30 seconds. If the detergent has produced abundant foam, then you don’t have hard water. If there is no foam or the water is cloudy, you likely have hard water, and you should purchase a formal testing kit to confirm and ascertain the hardness level. 

You can also get information on your water supply by asking the water utility company for a copy of their latest water quality report. However, these reports typically don’t reflect the water quality coming from your faucet as the tests are conducted at water treatment facilities.

How is Water Hardness Measured

Water hardness is measured in milligrams per liter (mg/L), which indicates the number of milligrams of calcium carbonate or magnesium in one liter of water. However, some testing facilities also use parts per million (ppm).

Once you have tested your water, you can compare your mineral levels to those given by the USGS.

  • Soft water: 0-60 mg/L
  • Moderately hard water: 61-120 mg/L
  • Hard water: 121-180 mg/L
  • Very hard water: Over 180 mg/L


The Bottom Line

While there are options such as boiling water to reduce the harmful effects of hard water, the best solution is to use a water filter. 

A high-quality water filter protects your pipework, produces a cleaner drinking water supply, and reduces harmful effects to your appliances. You generally need to replace a water filter every six months, so they are long-lasting and cost-effective.

You can choose a reverse osmosis filtration system that cleans and softens water simultaneously. Alternatively, you could use a water softener that uses ion exchange to replace magnesium and calcium ions with less harmful sodium ions. Both devices produce excellent results, and you can decide which one is right for you depending on which contaminants are present in your water supply.

Peter Lombardi

About the Author

Peter is a Los Angeles based water quality specialist, and works as a surveyor for businesses and communities looking to be informed and active about the quality of their water. He shares his expertise with 64 oz. to ensure everything is accurate, and to prevent the spread of misinformation about water contaminants.