How To Test Water Hardness

To say that hard water can be problematic is an understatement…

It creates mineral build-up around faucets, gives you low water pressure, wears down fixtures, reacts with cleaning products, gives you a slow flushing toilet, leaves you with spotty glasses and dishes, and it can even affect your laundry, causing dry and itchy skin.

How To Test Water Hardness

That’s why it’s worth testing your water to find out just how hard it is. If you know there’s a problem, then you can do something about it.

But most people have no clue whether the water in their faucet is hard or soft. So the first step to eliminating any of the problems caused by hard water is to find out whether your water is hard or soft and take things from there.

In this article, we’re going to kick things off with a few basics, including explaining what hard water is, what signs there may be that your water is hard, and three simple methods of testing for water hardness, including how to interpret the results.

And if it turns out that you do have hard water, we’ll point you in the direction of some of our other articles that might help you to treat it.

By the end of the article, you will know the signs of hard water and how to test for water hardness. 

What Exactly Is Hard Water Anyway?

Hard water is water with high mineral content. Hard water is formed when water moves through deposits of limestone, chalk, and the like. It is often high in the minerals calcium and magnesium.

Knowing The Signs To Look For

Here are some of the tell-tale signs that your water may be hard:

  • Low water pressure from faucets, shower heads, and your toilet
  • Reaction with cleaning products, such as a film on your hands when washing them
  • Spotty glasses and dishes, even after washing them
  • Dry and itchy skin when wearing freshly washed laundry
  • Your tap water tastes a little odd

(To be honest, this is only a brief list of the problems caused by hard water.)

How To Test For Water Hardness

It’s rarely sufficient to just assume that your water is hard, and due diligence requires that you test it to be sure. Here are three easy ways to test for water hardness.

1. Simple Soap Test

This test won’t provide you with a concrete level of water hardness, for that you will need to invest a few dollars in a water hardness testing kit (more on that shortly).

But it will tell you if you have a high level of hard water in your home.

Here’s what to do:

  • Grab a see-through bottle and fill a third of the way with water. Add a few drops of standard liquid soap, and shake it well.

If your water is hard, it will look cloudy and milky afterward, rather than perfectly clear.

2. Check With Your Water Provider

Your water provider is required to provide you with a consumer confidence report at least once a year, which should disclose the source of your water and what it contains.

This report may also specify the level of hardness of your water supply. If you find a recent report, check it against our water hardness scale.

If you’ve lost your water report, you can request a new one from your water provider or look it up online.

3. Use a High-Quality Hard Water Test Kit

Alternatively, you can spend a few dollars on a high-quality water hardness test kit, like this one available on Amazon. It’s affordable, the instructions are easy to follow, and you get a whopping 150 test strips in each kit, so you can test multiple areas.

If you find that you do have hard water, and you install a water softener, use these test strips to check your water regularly to judge the effectiveness of the water softener. 

You may also find testing kits that evaluate more than water hardness. For example, this 16 in 1 Drinking Water Test Kit, also available from Amazon, also measures acidity, and tests for the presence of chlorine, lead, iron, copper, nitrate, and nitrite.

How Is Water Hardness Measured?

How Is Water Hardness Measured

Water hardness is measured on a scale from soft to very hard. This measures the calcium carbonate in your water in one of two ways: grains per gallon (GPG) or milligrams per liter (mg/L).

Here’s a table that defines the level of hardness based on these measurements:

Soft waterLess than 1 GPG0 to 17 mg/L
Slightly hard water1.5 to 5 GPG17 to 60 mg/L
Moderately hard water3.5 to 7 GPG60 to 120 mg/L
Hard water7 to 10 GPG120 to 180 mg/L
Very hard waterMore than 10 GPGOver 180 mg/L

How To Treat Hard Water Effectively

If it turns out that you do have hard water, please refer to the following articles to learn how to rectify the situation:

Wrap Up

So, hard water can cause many problems, from leaving your dishes dirty to causing extensive damage to your plumbing, and leaving your laundered clothes itchy and uncomfortable to wear.

However, if you suspect you have a hard water problem, it is easy to diagnose and doesn’t take much effort to correct. But you must begin by determining if you have hard water before considering your options to improve it.


Mandy Anderson
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