How to Test Water Hardness: 5 Tried-and-True Methods

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Scaling, appliance damage and spots on your glassware are all signs of hard water damage in your home. Fixing the problem can save you hundreds of dollars in the long run – but how can you be sure that what you’re dealing with is hard water?

We’ve shared the 5 best methods of testing for hard water in this guide.

πŸ“Œ Key Takeaways:

  • You can test for hard water by using a simple soap test, a DIY hardness test kit, or a laboratory test.
  • Other ways to determine your water hardness are by checking for mineral deposits in your home or reviewing your latest Water Quality Report.
  • If you discover hard water, you can tackle the issue by installing a water softening system in your home.

πŸ”Ž How To Tell If You Have Hard Water

Just want an idea of whether or not you have hard water? Here are some good ways to check that don’t involve spending money on a test:

πŸ” Option 1: Make An Initial Assessment

If your water is hard, you’ll have noticeable signs around your home. Scale will build up on all surfaces that come into contact with your tap water.

Examine your water-using fixtures, pipes, and appliances, and look for the following:

  • White spotting on your dishes and glassware
  • Gray, starchy laundry
  • Stained coffee pots with floating mineral chunks in the water
hard water stains
Dry hair and itchy skin

πŸ“² Option 2: Check With Your Water Utility

If you use a municipal water supply, you can also determine your water hardness by speaking to your water utility.

Your local water treatment facility is legally required to send Water Quality Reports (or Consumer Confidence Reports) to its customers annually.

This report tells you where your water came from and what it contains, including its concentration of calcium and magnesium hardness.

πŸ‘¨β€πŸ”¬ You’ll be able to determine your average hardness by reviewing this report. Just keep in mind that the figure is only accurate to the day of testing, and hardness levels may fluctuate throughout the year or increase by the time water reaches your home.

If you tossed out your last report or can’t find it, contact your water utility provider and ask for the report to be re-posted or emailed to you.

πŸ§ͺ How To Test Water Hardness: 5 Easy Methods

Let’s look at the 5 easy methods to test for hard water at home.

🧴Method 1: Simple Soap Test

The soap test is a great way to determine water hardness. It can’t give you a specific hardness measurement, but it’s a quick and easy indicator of whether or not you have hard water.

You will need:

  • A plastic bottle with a lid
  • Pure liquid soap
  • A water sample from your faucet

Follow these steps:

  1. Fill a plastic bottle two-thirds full of water.
  2. Add a couple of drops of pure liquid soap to the bottle.
  3. Close the bottle lid and shake vigorously for about 30 seconds.

If you have soft water, your water will be clear and topped with a thick layer of white soap bubbles.

If you have hard water, the water will have a milky, cloudy appearance with a lack of suds on the surface.

Soap test

Method 2: Hard Water Test Strips

Hard water testing strips offer a quick and easy way to test your water hardness at home.

You can buy a hard water test kit online or at your local hardware store for less than $20.

You will need:

  • A sample of your water
  • A test strip

Follow these steps:

  1. Dip the test strip in a sample of cold water from your tap.
  2. Wait for the strip to change color.
  3. Compare the color of the strip to the included color chart. This will give you a water hardness reading.

DIY testing with strips and a color chart doesn’t give the most accurate test results to the exact grain-per-gallon of hardness, but it’ll help you to understand your water hardness category (soft, mildly hard, moderately hard, etc.).

Hach Total Hardness Test Strips

Method 3: Liquid Test Kit

A liquid test kit is another affordable at-home water hardness test. Liquid tests aren’t as popular as test kits that use strips, but you’ll still likely find them in hardware stores and online.

You will need:

  • A water sample
  • The liquid test

Follow these steps:

  1. Collect a small sample of your water (usually around 10 ml).
  2. Add the reagent drops one by one to the water, waiting between each drop.
  3. Continue until your water turns blue. This may take a few drops.

πŸ‘¨β€πŸ”¬ The more drops it takes for your water to change color, the harder your water. The test should come with instructions on how to read your results to accurately measure water hardness.

Lead and pesticide test kits of test assured water test

Method 4: Digital Testers

Some digital TDS meters also double up as water hardness testers. These are a good option if you want a quick and easy way to test for hard water at any time, without having to buy a test kit on every occasion.

You will need:

  • A water sample
  • A digital tester

Follow these steps:

  1. Collect a sample of water in a clean glass.
  2. Switch on the digital tester and dip the tip about half an inch into the water.
  3. Read the numbers on the display.

πŸ“Œ Note that TDS refers to all dissolved impurities in water, not just hardness minerals, so a TDS meter won’t give you 100% accurate results for hardness alone.

Tds meter of the zerowater pitcher

Method 5: Laboratory Test

If you have a bit more money to spend on a hard water test, consider paying for a lab test.

Laboratory testing gives the most accurate results. You’ll learn your exact hard water reading, in both PPM and GPG.

Most laboratory hard water tests cost in the range of $40-$80. Simply send a sample of your water to the laboratory and wait 1-2 weeks for the results to be emailed to you.

Getting tap water tested with tapscore

πŸ“Š Interpreting Your Test Results

Now you’ve tested for hard water, you need to be able to interpret your test results.

How is water hardness measured?

πŸ‘¨β€πŸ”¬ Water hardness is measured in GPG (grains per gallon). You can convert GPG to mg/L (milligrams per liter) or parts per million (PPM) easily.

For example, 7 GPG of hardness is equal to 120 PPM. Parts per million and milligrams per liter are interchangeable, so 120 PPM = 120 mg/L.

Generally, water hardness falls into 5 categories:

Hardness ClassificationGrains/ gallonmG/L or PPM
Slightly Hard1 - 3.517. - 60
Moderately Hard3.5 - 760 - 120
Hard7 - 10120 - 180
Very Hard>10>180
water hardness scale

πŸ“Œ What To Do If You Have Hard Water

So, you’ve tested your water and discovered that it has a high hardness mineral content. How do you clear these issues in your home?

The Solution: Install A Water Softener

The simplest solution is to install a whole home water softener or conditioner.

Water softeners are designed to eliminate hardness. They soften water by exchanging magnesium and calcium mineral ions with sodium ions (which can’t form mineral scale).

Water conditioners retain hard water minerals but crystalize them, preventing them from being able to form scale.

Water softening systems are an incredibly advantageous water treatment solution for your home.

Springwell water softener and iron filter well water treatment system

Here are some of our favorite benefits of water softeners:

  • Effective scale prevention. They prevent scale build-up on your faucets and appliances, including water heaters, showers, and faucets.
  • Penny-saving. They help you to save money with the use of fewer drops of liquid soap that produces more suds.
  • Improve appliance efficiency. They help to make appliances like your water heater more efficient.
  • Reduce cleaning efforts. They ensure your sinks, shower walls, and tubs look their best and reduce cleaning.

Soft water can save you money in the long run because it helps extend the life of the appliances in your home. The only effective way to achieve soft water is with a water softener.

❔ Test Water Hardness: FAQ

Can I test for hard water at home?

Yes, you can test for hard water at home. There are various at-home water hardness test methods, including using hard water test strips, doing a basic soap test, or simply looking for signs of hard water, like limescale around your faucets.

What’s the best way to test water hardness?

The best way to test water hardness is to pay for a laboratory test, which gives the most accurate results. However, this is also the most expensive method. If you want to save money, you can test water hardness with a DIY test kit or with the soap test.

water testing with tap score

What’s the simplest way to determine the hardness of water?

The simplest way to determine the hardness of your water is to use a DIY test kit. You simply dip a test strip in your water and wait for it to change color, then compare the color to a color chart. This indicates your water’s hardness.

What’s the difference between temporary and permanent water hardness?

Permanent hardness is caused by chlorides and sulfates of calcium and magnesium in the water, while temporary hardness is due to calcium carbonate and bicarbonate. Boiling water easily removes temporary hardness but not permanent hardness.

What is a good level of hardness in water?

A good level of hardness in water is anything below 3.5 grains per gallon or 60 parts per million. This indicates that the dissolved minerals content in water is low, and water is considered slightly hard. You probably won’t have issues with limescale and other hard water effects if your water’s hardness reading falls below this level.

  • Jennifer Byrd
    Water Treatment Specialist

    Jennifer is a seasoned water treatment expert with over 18 years of experience in the industry, dedicated to improving water quality for clients across the USA and around the world. Her passion for helping others and extensive networking skills have led her to hold leadership positions in organizations like the North Port Area Chamber of Commerce and the Florida Home Builders Association. Jennifer is currently a managing partner at Redbird Water of West Texas, where she specializes in providing water filtration and solutions for residential, commercial, and industrial clients.

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