Hard and Soft Water: What's the Difference?

Water can be classified as hard or soft depending on the amount of mineral salts it contains. Discover the difference between hard water and soft water in the following article.
Hard and Soft Water: What's the Difference?

Last update: 28 August, 2021

Water hardness is the term used to measure the amount of calcium and magnesium minerals found in a given proportion of water. This chemical characteristic allows us to classify the liquid into hard or soft water, and it’s important to recognize which one we have in our home. Keep reading to find out more about hard and soft water.

The properties of the water depend on the conditions of the ground through which it circulates because, while it travels underground, it comes into contact with the salts that are housed in the stones. In addition, elements such as iron, strontium, and barium also affect the hardness of the water.

What’s hard water?

Hard water is water with a high concentration of minerals. It usually occurs in coastal areas because they’re characterized by soils that have a high percentage of calcium carbonate.

One of the measures with which water hardness can be measured is the French hydrometric degrees (° H F). Because of this, experts have established that hard waters have between 32 and 54° H F and very hard waters contain more than 54° H F.

At the same time, hard waters can be temporary or permanent. The former are composed of calcium or magnesium carbonates and, when boiled, lose their hardness. The latter have calcium or magnesium sulfates and don’t decrease when boiling techniques are used.

What’s soft water?

Soft water is water that has a very minimal amount of mineral salts. It comes from mountainous places and wells because the rocks there don’t accumulate as much calcium and magnesium.

This type of water can also be measured with the French hydrometric degrees. Thanks to this, it’s determined that those with less than 7° H F are very soft and those with between 7 and 14° H F are soft.

Soft waters are ideal for use in the industrial sectors, as they allow optimum savings and don’t alter the performance of the machinery. It’s therefore essential for companies to check the levels of their water resources on a frequent basis.

A bottled water factory.
In factories, it’s important to measure the hardness of the water, as this determines the deterioration of components and equipment.

What’s the difference between hard and soft water?

Apart from the presence of minerals in each, there are other differences to be taken into account. The first is that while soft water’s suitable for cleaning, hard water weakens detergents because the soap molecules break down when they interact with calcium or magnesium ions.

Taste is another factor that changes. On the one hand, when tasting hard waters, one can feel that they have a stronger flavor, due to the high presence of salts. On the other hand, soft waters are characterized by having a much lighter taste.

In addition, each one produces different sensations on the skin. Soft waters are known for leaving the skin soft, while hard waters can cause dryness and irritation.

How can hard water affect the home?

Hard water is a factor that triggers many problems inside the home. At the plumbing level, it clogs pipes; when water is heated, it releases pieces of lime that gradually build up.

Likewise, the high concentration of lime also produces problems for the faucets and walls. This is because they produce a scale that noticeably stains the elements that are frequently sprayed with this water.

This type of water also causes damage to household appliances because the solid residues of salts can remain inside the machines. Hard water reduces the effectiveness of detergents and causes household cleaning costs to rise.

In addition, by not allowing the optimum performance of soaps, dishes acquire irreversible stains. What’s more, when washing clothes, garments become discolored.

A woman cleaning a kitchen sink.
A home with hard water will have problems in the medium term with the faucets and pipes due to salt deposits.

How to test the hardness of the water in your home?

Experts use a device called a hardness analyzer. It consists of a test tube and special liquids that react with the water.

The operation is simple, as you only have to fill the test tube with water and apply a few drops of the special liquid. Then, if the water resource acquires a blue color, it means that the water’s soft; if it turns red, it means that the water’s hard.

In addition to this, a home test can also be carried out using a bottle of water with salt and another with distilled water. During the process, you must apply detergent to both, shake them, and if the first option has less foam, it means that the household has hard water.

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