What is hard water, and is it okay to drink?

Published 15.11.2023

You may have heard of hard and soft water, but how are they different? Hard water is characterised by its higher concentration of calcium, chlorides, sulphates or magnesium carbonates. 

Soft water has a less complex composition, containing fewer minerals and lower levels of magnesium and calcium. It’s ‘softened’ through a process called ion exchange, where these minerals are replaced with sodium ions. As a result, soft water has a low sodium content. 

The minerals in both kinds of water are not harmful to human health. On the contrary, these nutrients are essential for maintaining healthy bones, muscles, and blood. 

How can you tell if water is hard or soft?

The simplest way to tell if your water is hard or soft is by using a hard water map. 

AquaCure’s water map is quick and simple to use: all you need to do is input your full postcode, and the map will tell you if you live in a soft or hard water area. 

However, if you want some physical indicators, look for the following signs: 

Signs of hard water

  • Skin problems: Households in hard water areas may be more prone to skin issues. Hard water can cause dry, itchy skin and exacerbate conditions like eczema and psoriasis.
  • Rougher clothes: Clothes washed in hard water can feel stiff, show colour changes, and wear out faster due to mineral deposits.
  • Plumbing issues: As hard water travels through your pipes, it may cause a build-up of minerals. This build-up can then corrode pipes and lead to issues with your water pressure. They can become easily clogged, and, over time, you may find your shower or washing machine produces a reduced amount of water. 
  • Dull hair: It may lead to mineral buildup on hair, making it flat, lifeless, and prone to breakage.

Signs of soft water

  • No scale formation: Soft water doesn’t deposit minerals in pipes, cookware, or washing machines. 
  • More bubbles: Soft water feels slippery and lathers easily with soap. 
  • Acidity: If the pH level of the water drops below 6.5, the water becomes acidic. Acidic water can sometimes lead to corrosion in copper pipes, characterised by a greenish/blue oxidation that’s especially visible in water fixtures (e.g. showers). 
  • Cleaning efficiency: Soft water interacts less with detergents; it’s better for cleaning and reduces the need for harsh chemical detergents. You may also need to use less soap than recommended.

Are there any health risks associated with hard water?

No, there are no health risks associated with drinking hard water. 

In fact, several studies have identified the positive health benefits of hard water, with particular reference to the heightened levels of magnesium and calcium. 

Cardiovascular health

Research indicates that the minerals in hard water, specifically calcium and magnesium, may have protective effects against cardiovascular disease. 

Calcium and magnesium are essential for various bodily functions, including muscle and nerve function, blood sugar control, and blood pressure regulation. Their presence in drinking water can positively affect the body’s intake and improve cardiovascular health. 

Bone and muscle health 

Calcium is crucial for maintaining healthy bones, muscles, and blood, while magnesium aids calcium absorption and promotes vitamin D production within the kidneys. Hard water, being a natural source of these minerals, can contribute to bone and muscle health.

Are there any health risks associated with soft water?

As with hard water, there are no health risks associated with drinking soft water. However, there are some considerations that individuals with specific health conditions and mineral deficiencies may need to make.

Sodium intake 

The amount of sodium added during the softening process is small but can vary depending on the hardness of the original water. In areas with very hard water, the sodium content in softened water may be higher. 

For most areas, especially in the UK, the sodium levels in softened water are well within the recommended limits. However, it’s important to note that the additional sodium intake could be a concern for individuals on a reduced-sodium diet or those with high blood pressure.​

Reduced mineral intake 

Soft water has lower levels of calcium and magnesium, two minerals that play essential roles in bone health and muscle functioning, among other things. 

While the reduction in these minerals in softened water is usually not significant enough to impact health adversely (as most dietary mineral needs are met through food), it’s still something that those with deficiencies should consider.