How To

How to Test for Hard Water in Your Home

Written by Mint.com
Published Aug 23, 2013 - [Updated Dec 17, 2021]
2 min read
The views expressed on this blog are those of the bloggers, and not necessarily those of Intuit. Third-party blogger may have received compensation for their time and services. Click here to read full disclosure on third-party bloggers. This blog does not provide legal, financial, accounting or tax advice. The content on this blog is "as is" and carries no warranties. Intuit does not warrant or guarantee the accuracy, reliability, and completeness of the content on this blog. After 20 days, comments are closed on posts. Intuit may, but has no obligation to, monitor comments. Comments that include profanity or abusive language will not be posted. Click here to read full Terms of Service.

Having “hard water” means that your water supply contains high levels of minerals like calcium and magnesium.

While hard water is generally harmless to drink, it can damage your boiler and clog your pipes, which are expensive to repair or replace (a new boiler can cost as much as $10,000!).

To prevent these problems, it’s important to identify and remove hard water by installing a water softener. Use these steps to test for hard water.

What You’ll Need

clear plastic bottle with a cap
liquid dish soap

Step 1

Fill your plastic bottle with about 10 ounces of water from your kitchen sink. Add about a teaspoon of liquid dish soap, close the plastic bottle and give it a good shake.

If the soap foams up naturally, you probably don’t have hard water and can end your test at this point.

If it doesn’t foam, but instead forms a milky film at the top of the bottle, hard water could be an issue and you need to continue the test.

Step 2

If you have public water, contact your local water utility and ask them for a recent hard water reading.

If you have a private well, you’ll need to test your water yourself.

Contact your local department of health and ask them which labs in your area can test your water. You can usually send a sample of your water to them and have it tested for free.

It’s generally best to avoid home tests, which can be inaccurate and unreliable.

Step 3

Check your results.

Hard water is generally measured in grains per gallon (GPG) of dissolved minerals.

If your water has more than 4 GPG, your hard water levels are considered high.

Step 4

If you GPG is 4 or higher, it’s a good idea to install a water softener to reduce your levels.

A water softener can cost anywhere from $100-$3,000 depending on the model, method of softening and water volume requirements of your house.

It’s also a good idea to have your water softener professionally installed, which can cost $100-$600.

Step 5

Once your water softener is installed, maintain it! To learn more, read: Inspect Water Softener.

BrightNest is a free site that provides tools and tips to homeowners to help them save money, get organized and keep their homes in great shape. Sign up for a free BrightNest account today!