What Is Hard Water & How To Test For Water Hardness

Updated 2/15/2023

If you’ve ever experienced any signs of “hard” water in your home, your first instinct is likely to figure out the steps to fix the problems – quickly. So we’ll go through what water hardness is and how to test it. To briefly refresh your memory, hard water usually causes certain inconvenient, embarrassing and costly issues such as:

  • Spotty, filmy dishes and glassware;
  • Soap scum on mirrors, fixtures and glass;
  • Ugly stains in sinks and tubs;
  • Low water pressure due to clogged pipes;
  • Higher electricity bills;
  • Damage to water-heating systems, among others.

Hard Water Stained Faucet

It’s no wonder why hard water is one of the most common household problems in America, affecting 85% of homeowners across the country.The first step to combating hard water problems is to test your water for hardness and measure its hardness level. You can achieve this by implementing a hard water test so you can determine if your water is hard, how hard it is, and the best treatment method to use. The most accurate hard water test is done through an independent laboratory, using a water sample you provide. However, a comprehensive water test kit can be pricey and can take a while for some labs. The lab we use here at SpringWell Water has a turn around time of 1-3 days after receipt of your water sample.

For faster and cheaper – less accurate – results, try one of the methods below to get a good estimate of your water’s hardness level.

1. Quick Soap Suds Water Bottle Test

One of the easiest and quickest options for a hard water test is the Soapsuds Test. To carry out this test, you need a clear, clean, empty glass or plastic bottle with a tight-fitting cap. Fill the bottle about one-third with water straight from your tap, add a few drops of pure liquid soap and shake vigorously for about 15 seconds. Next, set the bottle down and observe the solution.

If there are no fluffy bubbles in the water or it appears cloudy and/or milky, your water is hard. Soft water would foam up quickly and create bubbles, and the resting water at the bottom would be clear. You have to keep in mind, however, that some soaps are formulated with detergents, so they lather regardless of your water type. For the best results, use a basic soap, such as Castile. Soaps like this one have no dyes, detergents or perfumes.

2. Check with Your City or Water Provider

If you get your water through a municipal service line, you can contact your local water provider and ask for their latest water quality report. Many of these utilities also post their reports online, so you can do a quick search. Some of the reports can be very technical, so you must know how to read and understand a water quality report.

A drawback of this option is that the reports might not necessarily reflect the water quality directly at your tap because the water is tested before leaving the treatment facility and can pick up impurities from the piping on its way to your home. Despite that, water quality reports can provide a good idea of the water hardness in your area.

Most utilities report their water hardness numbers in milligrams per Liter (mg/L) as calcium carbonate.

3. Use a High-Quality Hard Water Test Kit

Well water test kit by ETR LabsA home water test kit is the simplest (and probably the best) way to check your water for hardness minerals. A regular kit usually includes water test strips and a color chart. You can purchase a test kit from a local home improvement store or a reputable online retailer. We offer a premium line of water test kits that tests only for specific contaminants as well as overall water quality, pH and safety.

Three common types of water test kits are available for purchase, namely water test strips, color disk kits, and digital testing kits. Water test kits are the most popular of the three. They are small, single-use strips that change color based on the presence of certain contaminants.

To use the strip, fill a container with water from your tap, then immerse the test strip in the water. Next, compare the resulting color of the strip to the color chart provided with the kit. Each color on the chart corresponds to the hardness of your water, with results measured in grains per gallon (gpg). The instructions will tell you how hard your water is based on the result.

You can always purchase a water test kit from SpringWell and have the results within a few days of submissions. Click Here.

How is Water Hardness Measured?

Most water hardness tests report hard water levels in grains per gallon (g). However, some laboratories use milligrams per Liter (mg/L), or parts per million (ppm). One part per million is simply stating that out of one million units, one unit is a hard water mineral. Grains per gallon is the equivalent of one dry grain of wheat or about 1/7000 of a pound. It takes 17.1 ppm to equal to 1 gpg.

If your hard water test displays or produces the result in parts per million or milligrams per liter, you can take the total hardness level and divide it by 17.1 to determine the hardness in grains per gallon. For instance, if your hard water test shows 182 mg/L, you have 10.6 gpg. You can convert mg/L or ppm by dividing the total hardness by 17.1 to get the grains per gallon hardness.

Here’s a simple water hardness formula using American degree equivalent to mg/L:

Water hardness (mg/L) = Ca(mg/L) x 2.497 + Mg(mg/L) x 4.118

Ca = Calcium content

Mg = Magnesium content

Water Hardness Scale: How to Interpret the Water Hardness Testing Results

The U.S. Geological Survey uses the following scale to determine the hardness of the water. Note the value of the calcium carbonate in your water quality report or your test kit results and compare it to the scale below.

Classification Mg/L or ppm Grains per Gallon (gpg)
Soft 0 – 17.1 0 – 1
Slightly hard 17.1 – 60 1 – 3.5
Moderately hard 61 – 120 3.5 – 7.0
Hard 121 – 180 7.0 – 10.5
Very hard 180+ 10.5+

In short, if your hard water test result is less than one grain per gallon (17.1 mg/L or less), you have soft water. Anything higher than this value indicates hard water.

How to Treat Hard Water Effectively

Springwell water softener
SpringWell’s Salt Based Water Softener

Just because the test results indicate that you have hard water doesn’t mean you have to sit back and live with its damaging effects. Traditionally, a salt-based water softener has been used to treat hard water by replacing hard water mineral ions with sodium ions. While effective, salt-based softeners discharge a lot of salty wastewater, which eventually ends up in the natural environment, affecting plants and animal life. The salt content can also have adverse effects on people who require low-sodium diets. 

The salt-free alternatives, however, offer a more environmentally-friendly way of controlling water hardness. These softeners require no electricity and produce no wastewater. They soften water by crystallizing the hard water minerals so they no longer stick to surfaces, thus reducing scaling. Unlike salt-based water softeners, the non-salt variants do not require you to recharge the system with salt, which significantly reduces maintenance costs.

While there are several differences between salt-based water softeners and salt-free water softeners, choosing the right type all depends on your situation and personal preference. If you need any assistance picking the one that is most suited for your needs, don’t hesitate to contact us.


Hard water is no stranger to many households in the U.S., damaging almost anything that it comes into contact with. But by testing your water with the three easy methods above, you can stop hard water in its tracks and remove it from your home before it does any damage. Springwell Water Systems is here to help you achieve that and more, so please reach out to today to get started or shop our water softeners.