Hard vs. Soft Water: Everything You Need to Know

What type of water is the healthiest? Find out when we compare hard vs. soft water.

Hard water may be full of minerals, but is it good for us to drink? Soft water is often treated to remove minerals, but is it any better? Knowing whether your water is hard or soft is easy, if you know how to use the tests available.

It’s important to know when water is too hard and needs treatment, since the minerals in hard water can cause problems with your appliances and water fixtures. Let’s take a closer look.

What is Hard Water?

Hard water has a high mineral content due to traveling underground through chalk and limestone. These deposits are mostly made up of calcium and magnesium carbonates. When water runs through or over these deposits, it becomes hard (1).

The word “hard” may make you think this water isn’t good to drink. However, hard water is actually beneficial to our health, and getting extra calcium and magnesium through drinking it is a bonus (2).

However, hard water can still cause trouble in certain areas of the home. The minerals can cause limescale buildup that can clog a faucet or showerhead.

In industrial settings, hard water can be detrimental to machinery and processes connected to water by causing buildups and blockages. When the pipes are clogged, a lack of lubrication can lead to working parts overheating and ceasing to function. Water hardness is monitored continuously using strip tests and other monitors to avoid breakdowns that could be costly.

Advantages of Hard Water

  • Health benefits: This is the main advantage. The high mineral content makes it a much better option for people with cardiovascular disease (3). It’s also very beneficial to our bones and teeth as it provides much-needed calcium.
  • Reduces lead contamination: In areas with hard water, the minerals have shown to build up on the inside of the pipes. This prevents the water from bonding with the lead in the pipes, preventing it from entering the water supply. This isn’t to say that areas with hard water won’t have lead. However, the risk of contamination can be reduced (4).

Disadvantages of Hard Water

  • Mineral buildup: This is a major disadvantage for appliances and plumbing. The buildup can spike energy bills because appliances need to work harder.
  • Skin and hair: Hard water can also affect our skin and dry out our hair, making it brittle and prone to damage.

What is Soft Water?

Soft water has a low concentration of ions, particularly calcium and magnesium. It can be created by treating hard water, but it also occurs naturally (5).

In places with hard and calcium-poor rocks, the water can’t pick up as much of the mineral — resulting in soft H2O. Because soft water is low in calcium ions, it won’t cause soap scum. It also won’t cause limescale or other mineral buildups (6).

People often confuse soft and softened water. Soft is natural, whereas softened water goes through a process that eliminates minerals. Softened water can be high in sodium and bicarbonate ions, depending on how it’s treated — this can cause water to taste salty (7).

There are different requirements to determine whether water is soft or hard, depending on the country or state. In the USA, water should have less than 1 gpg (grain per gallon) of dissolved minerals to be classified as “soft” (8).

Advantages of Soft Water

  • Softer laundry: Soft water is better to clean with since it won’t dull clothing and won’t leave spots or marks.
  • Better for appliances: It’s also much healthier for your appliances, like dishwashers, washing machines, and water heaters. Bills are usually significantly lower in a soft water household because devices can work at an optimal level.
  • Skin and hair: As we clean ourselves in soft water, it preserves the moisture in our skin and hair. It also won’t leave a film on the skin like hard water tends to do (9).

Disadvantages of Soft Water

  • Health concerns: However, soft water isn’t as good for our health as it is for appliances. If you’re softening your water, sodium is added while minerals are removed. This causes the salt content of the water to rise, which is unhealthy if you’re on a low-sodium diet (10).
  • Doesn’t combat lead: Softened water is also more volatile due to the softening process. It easily absorbs contaminants such as lead as it runs through pipes. Lead is a serious concern in the U.S. It’s a heavy and dense metal that is or was commonly used to manufacture water pipes, and has a low melting point, which means it easily dissolves in water which we then drink (11).

Differences Between Soft and Hard Water

Hard and soft water differ in many ways — and both types have benefits and disadvantages:

Content of Minerals

The main difference between hard and soft water is mineral content. Rainwater is soft as it falls from the sky, but it changes as it runs through the ground and into our waterways.

How much it changes depends on the mineral content of the ground. Areas with rocks rich in calcium and minerals will have hard water, but locations with calcium-poor rocks will have soft water.

The main minerals you can find in hard water include lime, chalk, calcium, and magnesium. These, especially magnesium, are all essential to our health (12).

Soft water, on the other hand, isn’t as good to drink. Because of the lack of minerals and the higher content of salts, it’s not recommended for people with cardiovascular issues (13).


You can easily drink both hard and soft water. However, if you want any health benefits, hard water is the best due to its mineral content (14).

Many prefer the taste of hard water to soft — due to the minerals, it has a richer, more pleasant taste (15). Soft water, on the other hand, can have a salty taste due to the sodium.


While hard water is the healthiest option to consume, it can be bad for appliances and fixtures in a household.

The high content of minerals can quickly cause limescale and mineral buildup in faucets and showerheads. Water heaters can also become clogged due to buildup, and they often require frequent flushing to get rid of calcium (16).

Hard water is also a pain when cleaning various areas of the house. It can cause watermarks and spots on glass and windows, and make your clean laundry look grimy.

Soft water is much more gentle on water fixtures, and won’t cause any buildup due to the lack of minerals. It’s easy to clean with because soap suds form much easier (17). Households with hard water often have to soften the water to avoid buildup and water spots in appliances.

Skin Care and Health

Hard water is not kind to the skin, causing it to become dry and scaly. The high mineral content can also be damaging to your hair, turning luscious locks dry, dull, and brittle.

This can be exacerbated by the overuse of shampoo and hair products — the minerals can also form a film on the hair, similar to limescale. The minerals will also make hair more prone to damage and can cause discoloration (18).

Soft water is gentle on skin and hair. It will help to preserve moisture and prevent breakage. If you have color-treated hair, soft water will help to maintain your color for longer.

Testing Water Hardness

Testing whether your water is hard or soft — and how hard it is — is quite easy. There are many ways to check your water, and you don’t need to purchase any expensive kits.

1. Shower or Tub Test

This is probably one of the easiest ways to know whether your water is hard or soft. After taking a shower or bath, you might notice a white scale on the sides and bottom of the tub or shower. The scale is caused by hard water and is a buildup of minerals.

If you notice this, it could indicate that your water is very hard. This could damage your fixtures and appliances, as we saw discussed above.

We highly suggest that you find a way to soften the water slightly to avoid any damage. This can be done using different methods, the most common and effective being an ion exchange system. This system replaces calcium and magnesium ions for salt ions; thus removing the hardness (19).

2. Bottle Test

For this test, you need a plastic bottle with a lid and dish soap.

  1. Fill a bottle: Fill the bottle halfway with water and add five squirts of soap.
  2. Shake: Close the lid and shake it vigorously until it begins to foam.
  3. Inspect: After shaking the bottle, watch the foam for a while. If it stays, it means your water is soft. However, if the foam disappears rather quickly, your water is hard.

3. Test Kits

There are two options here:

  • Water test.
  • Wet strips.

Water Test

With a water test kit, you can get an accurate measurement of the mineral content in your water. They’re easy to use, and you get everything you need in a kit.

Start by filling one vial with water, add the required amount of solution and then shake it for the time necessary. Compare the results to the chart in the kit.

Wet Strips

Another type of test kit is wet strips. These are easier to use — simply immerse the strip in a glass of tap water. The strip will change color, and you can then compare it to a chart.

The Results

When it comes to hard vs. soft water, the advantages and disadvantages differ significantly. Hard water is high in minerals such as calcium and magnesium; it’s healthy to drink and can maintain the health of teeth and bones. However, it can quickly dry your skin and hair, as well as cause limescale in appliances and water fixtures.

Soft water is much more friendly towards our skin, hair, and appliances because it’s low in minerals. But, it’s high in sodium and is, therefore, not recommended for people with heart-related issues.

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About the Author

Peter Gray

Peter has been a homeowner for 35+ years and has always done his own repair and improvement tasks. As a retired plumber, Peter now spends his time teaching others how they can fix leaks, replace faucets, and make home improvements on a budget.