How to Measure Your Water Hardness: Let’s Find Out


You might have heard that hard water causes a bunch of issues like water spots and deposits in plumbing systems. While that is totally true, some of you might want concrete proof that the water is hard indeed; proof that there’s a high percentage of the minerals that are known to cause water hardness.

Then again, you might want to assess the effectiveness of your water softener. To do that, you will need a way of measuring water hardness before and after the softening process.

That is what this article is about. We’re going to look at how to measure water hardness at home using the easiest methods.

Measuring Water Hardness

Before we even jump into the actual ways of measuring, how about you learn about the units used. Here are the most common units:

  • Grains per gallon
  • Milligrams of calcium(Ca)/magnesium(Mg) per liter
  • Parts per million – this is the same as milligrams per liter (mg/l)

Your options: you can either use basic ways of measuring water hardness, or go the more accurate way of having your water samples tested in a lab.

Here are the different degrees of water hardness:

  • 0 to 17 mg/l of Ca/Mg – soft
  • 18 to 60 mg/l of Ca/Mg – slightly hard
  • 61 to 120 mg/l of Ca/Mg – averagely hard
  • 121 to 180 mg/l of Ca/Mg – hardAbove
  • 180 mg/l of Ca/Mg – extremely hard

The methods we will look at in this article are:

  • Simple soap and water method
  • Test strip method
  • Digital ppm meter technique

1. Water and dish soap

Let’s start with the most basic way of measuring water hardness. Here are the items you will use:

  • A water hardness test kit bottle or a small glass bottle
  • A drinking glass or a measuring cylinder
  • Dish soap

This simple test measures the hardness of water in grains per given volume of water, and these are the steps to follow:

  • Add some water into the bottle. To ensure that the test is not affected by any impurities that might have come into contact with the bottle, rinse it twice with the liquid to be tested then do the test with the third refill.
  • Put a few drops of liquid dish soap in there
  • Shake the bottle and observe the suds or rather the cloudiness

The more the suds or the cloudiness, the higher the degree of hardness. If after adding the dish soap there’s no cloudiness, the water is soft. You can do this test before and after the softening to see whether your softener is working properly.

Remember, this method is rather crude and doesn’t give you a clear picture of what exact level of hardness you’re dealing with. Now let’s look at a more accurate method of testing water hardness – that of using test trips

2. Using Test Trips to Measure Hard Water

Paper and plastic test strips designed for testing water hardness are available for purchase online; Amazon has a full range of them. These work in a similar to test tablets and these are the general steps that you normally have to follow:

  • Put some water in a clean container. Again, to make the test more accurate, be sure to rinse the container with the water being tested.
  • Place the test strip or the tablet in the water. Most times these test strips or tablets come in a bottle, and on the outer sides of this bottle, you might find some directions for use as well as some color ranges marked with different degrees of hardness.
  • If you used a test strip, part of it or all of it would have a color change. Hold the strip against the colors marked on the bottle and the one it matches up with is the degree of hardness of the water. Normally, they even have a scale, so you have more precise results.
  • In case you used a tablet, roughly the same story applies but, in this case, it is the color of the tablet and the water that changes. You then have to match the water’s color up to a color chart (normally comes as part of the package) and the color it matches with indicates the degree of hardness of that water.

3. Digital PPM Meter

Do you need a much more effective way of assessing the hardness level of your water? Consider using a TDS/PPM meter. TDS stands for total dissolved solids while PPM stands for parts per million and it’s the same thing as milligrams per liter (mg/l).

You can get a digital PPM meter from Amazon for as low as $15, and so you might agree it’s an inexpensive option as well. 

Here’s how to use a TDS/PPM meter: stir the water gently with the gadget. Remove it from the water and take the reading, which is normally displayed on the device’s LCD screen within seconds. The reading disappears within around 2 minutes.

Frequently Asked Questions (FAQs)

1. What is TDS?

2. How do I know that my water is hard without measuring anything?

3. Is rainwater hard water?

4. Which one between hard water and soft water is preferred for drinking?

Final Word

There are several other methods of testing water hardness, like titration, but those are a little too inconvenient for personal needs at home unless you’re a scientist.

You can use the test strips, but for utmost convenience and ease, we recommend you go for the digital TDS/PPM meter. While the test strips run out, the meter goes on serving you for years; the only thing you will be doing is replace the battery after a while. Again, the meter is faster and more accurate with a precise reading.

Thanks for reading and hopefully this helped you to on how to measure the hardness of your water. Comment below if you have any questions.

Last update on 2021-05-14 at 23:05 / Affiliate links / Images from Amazon Product Advertising API


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