Hard water

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What is hard water?

Water is considered "hard" when it has relatively high levels of calcium (above, left) and magnesium (above, right) and other metals. The more minerals that are present the harder the water is. It is referred to as "hard" water because it requires more soap for a good lather, making it harder to clean with than soft water. There are both benefits and drawbacks to having hard water, depending on what the water is being used for.

Why care about the hardness of your water?

Benefits of hard water: Problems that hard water may cause:
  • Calcium and magnesium are part of the dietary needs of humans. Hard water can be a valuable source for these nutrients.
  • Some studies have found a correlation between hard water and lower cardiovascular disease mortality.
  • Hard water is less likely than soft water to cause corrosion of pipes. Soft water can dissolve certain metals that are potentially toxic (like cadmium and lead).
  • Tastes better
  • Hard water has less sodium than soft water. Soft water can be a significant source of sodium and may be of concern to those who need to restrict their sodium intake for health reasons.
  • Spotting on glass
  • deposits in hot water heaters
  • scalding on sinks and fixtures
  • clothes feeling harsh or looking dingy
  • film on bathroom surfaces
  • sticky dull hair

How do I find out how hard my water is?

To test the hardness level of your water contact a certified testing lab near you. For more information click here.

How should I treat hard water?

Softening water is the most common treatment for hard water. This can be done by installing a water softener on washing machines or dishwashers. Some new dish washers may already come with a water softener. To treat an entire house for hard water a water softening system can be installed. These systems exchange calcium and magnesium ions with other ions that do not cause hard water (like sodium or potassium). In some cases people bypass the water softener system by having a separate drinking water tap. This way they are able to receive the health benefits of drinking hard water, without the negative effects of hard water on hot water heaters, washing machines, and plumbing. Another option to avoid drinking high levels of sodium from soft water would be to install a reverse osmosis filter at the drinking water tap. Reverse osmosis can filter out sodium and alleviate health concerns related to high sodium intake.