What is hard water?

Posted: 7th March 2025 | Author: Adam Brown | Category: Plumbing

If you’ve never looked into it before, the term ‘hard water’ can be a confusing one. After all, how can a liquid be classed as hard or soft? Fortunately, the difference between hard and soft water is simple to understand, and knowing how it affects you can have a big impact on the longevity of your metal plumbing components and appliances. 

What is water hardness?

Water hardness refers to the mineral content of the water being supplied to your home. When rain falls from the clouds, it typically has a very low mineral content or no mineral content at all - this is known as soft water. 

From there, the rain lands on the ground and filters down to the bedrock. Some types of rock are more porous than others, so water can soak in more easily, and as it does, it dissolves some of the compounds that make up the rock. In doing so, tiny particles of substances such as calcium, iron or magnesium are picked up by the water and carried away. 

Eventually, this water flows into streams and rivers, and then into lakes and reservoirs. At this stage, it can enter our water supply and, after a treatment process, be transported to our homes for all our water needs. 

If the bedrock in your area tends to be made up of lots of non-porous rock like granite or basalt, then it’s harder for water to dissolve minerals from it. That means you end up with a lower mineral content in the water you use at home - you have soft water. 

If, on the other hand, you live in an area where there is lots of sedimentary rock like limestone, chalk or sandstone, these kinds of rocks tend to have less resistance to water erosion. This means you’ll likely have more mineral deposits in your water, so it may be classed as hard water. 

Generally speaking, this is nothing to worry about - hard water isn’t harmful for your health. In fact, the added mineral content is sometimes seen as beneficial because it supplements the minerals you get from your diet. 

However, hard water can cause a build-up of mineral deposits known as limescale. This can happen in the pipes of your plumbing system or even in appliances like your kettle or washing machine - and over time it can lead to damage. 

Fortunately, there are simple solutions to avoid this kind of damage. You can use water softeners to help reduce the mineral content of your water as it reaches you, relieving some of the problems caused by hard water. Then, as limescale builds up, you can use cleaning solutions to help get rid of it. 

Is my water hard or soft?

In order to combat hard water in your home, business premises or elsewhere, you first need to know if hard water is even a problem in your area. As mentioned, the type of bedrock near where your water comes from is the main indicator - but we don’t expect you to know that off the top of your head! 

Because hard water is largely determined by geology, it tends to be the case that certain areas have hard water and others have soft. So, you can get a rough idea of how hard your water is by where you are in the country. 

The general rules are:

• Scotland, Wales, Northern Ireland, the North West and the South West are predominantly soft water areas
• The South East, the Midlands and the North East are mostly made up of hard water areas. 

For a more specific understanding of whether your area has hard water, there are plenty of checkers online that allow you to input your postcode for a more accurate result.  

You might also be able to get an inkling of whether your water is hard or soft by looking at the physical impacts of it. We’ve mentioned that hard water leads to limescale deposits, but it can also:

• Make your water taste different when compared to soft water
• Make it more difficult to clean your clothes, dishes and even yourself - so you need to use more soap or detergent
• Lead to lower water pressure in the shower
• Leave your hair and skin looking dull
• Cause it to take longer to heat water or your home. 

Of course, these signs can be caused by other things - for example, you might have a boiler or radiator problem that affects the efficiency of your central heating. But if other fixes aren’t working, it may be worth investigating your water hardness. And if you find you are impacted by hard water, remember there are solutions to help.

The Author: Adam Brown

With a background as a Mechanical Engineer, I started Nationwide Supplies alongside my brother with a vision to modernise what seemed a stuck-in-its-ways industry in the builders merchant sector.  Since 2011 it has been my goal to source quality products at the correct prices to be able to offer a saving to customers along with high quality customer service which offers quick delivery and superior technical knowledge in the industry.  

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