The facts on hard water

Hard water is something that most of us are familiar with. Hard water can be costly and troublesome, causing many problems in the home and with our bodies. If you experience problems resulting from water hardness, we explore hard water facts so you can choose the best solution.

What is hard water and soft water?

Hard water is classed as water containing calcium and magnesium ions, not frozen water. Depending on the concentration of the ions determines the water hardness. Soft water contains very little or no magnesium or calcium minerals and feels softer to the skin.

Hard water is determined by the amount of dissolved mineral content, such as magnesium and calcium, in the water. The greater the concentration of minerals, the harder the water. Rainwater is naturally soft until it percolates through limestone and chalk, causing the minerals to dissolve.

Learn more about what makes water hard in our hard water guide.

How to measure water hardness

Water hardness can be measured in parts per million (PPM). PPM is affected by the number of hardness particles dissolved in the water per million particles.

PPM hardness levels are:

• - Soft - up to 50 PPM
• - Moderately soft - between 51 and 100 PPM
• - Slightly hard - between 101 and 150 PPM
• - Moderately hard - between 151 and 200 PPM
• - Hard - between 201 and 275 PPM
• - Very hard - between 276 and 350 PPM
• - Aggressively hard - above 350 PPM

Hard water in the UK

In the UK, around 60% of all water supplies are hard. Hardness levels differ across areas of the UK. The North and South-East regions of the UK have the softest water supplies, with the East and Central regions having the hardest supplies. Scotland and Ireland have soft water supplies.

A map showing the water hardness across England:

Water supplies in London are hard, with London having the hardest water supply in the UK. Hardness levels in London are over 200 PPM, although levels can vary throughout the city. Epping, a small village on the outskirts of London, has the hardest water supply of 370 PPM.

Is London water hard or soft?

Water supplies in Yorkshire are soft. Yorkshire has one of the softest water supplies in England, with moderately soft water supplies. Fun fact: Yorkshire Tea has special deliveries of hard water from Yorkshire Water for their tea buyers, as water hardness can affect the taste of a brew.

Is Yorkshire water hard or soft?

You can test water hardness in several ways, including home test kits, mixing soap and water, or looking for scale deposits. Depending on how accurately you want to test water hardness will determine which test method you choose.

How to test water hardness

For those who want to know whether your water supply is hard, look out for scale deposits around water outlets or in the kettle. Scale deposits are a result of the calcium and magnesium minerals.

Another method is to add a few drops of washing-up liquid in a clean bottle. Fill the bottle 2/3 full of clean water from the tap. Shake the bottle vigorously for a few seconds. Hard water will look cloudy and form very few bubbles, while soft water will stay clear and fill the bottle with bubbles.

You can also use a home test kit that provides a much more accurate test to determine your water supply’s PPM or mg/l level. Home test kits use a solution that is mixed into water. Depending on the colour change of the water tells you the water’s hardness, checked against a provided chart.

How to remove hard water stains

Hard water stains are a common problem resulting from the high mineral content of the water. These mineral stains can be difficult to remove. Consider soaking a small amount of vinegar to help remove such stains. After 15 minutes, the stain should be easier to remove.

Is hard water bad for you?

Hard water can provide health-beneficial nutrients that support our bodies and keeps us healthy. However, it can lead to skin and hair problems.

Is drinking hard water bad for you?

No, drinking hard water is not bad for you. The magnesium and calcium minerals contribute to our daily mineral intake. Consuming sufficient minerals helps with normal bodily processes, such as aiding muscle and nerve function.

Does hard water cause dry skin?

Yes, hard water minerals can cause dry skin. The minerals are bad reactants with fatty acids in soap. This bad reaction creates soap scum, leaving an insoluble layer on the skin. This blocks and clogs the skin pores, preventing your skin from keeping naturally nourished and moisturised.

Find out more about the effects of hard water on skin and hair.

Can hard water cause eczema?

Hard water can negatively affect eczema, causing inflammation of existing skin conditions. Research suggests that hard water minerals can contribute to the development of eczema, particularly in early life.

Does hard water cause hair loss?

Hard water does not cause permanent hair loss. While it can cause a dry scalp or leave hair feeling dry and faded, any hair loss is not permanent. Treating hard water can help rectify any hair or scalp problems.

Does hard water cause kidney stones?

Drinking hard water is not a direct cause of kidney stones. Research has found no direct correlation between drinking calcium in hard water and developing kidney stones. Drinking water and staying hydrated is recommended to reduce the risk of kidney stones.

How to soften hard water

There are two main ways you can overcome the problems with hard water; a water descaler or a water softener. Both devices work differently and are suited to different people depending on the effects of hard water.

Water descaler

A water descaler (or water conditioning) device is a small device fitted to the main water supply. Attaching small coils of wire around the inlet pipe, an electromagnetic charge is emitted through the pipe, affecting the behaviour of mineral ions that prevents scale build-up with hot water.

A water descaler can help you to save money by reducing scale build-up inside pipes and heating systems. Water pressure also improves due to the decreased build-up inside pipes. Over time, scale builds up inside water pipes, reducing water flow and decreasing the efficiency of household appliances. A water descaler can help overcome these problems.

Water softener

A water softener uses the ion exchange process to replace calcium and magnesium minerals with sodium, resulting in soft water. Installing a water softener is only recommended for hard water areas as the process can be costly.

Water softeners contain resin beads that make the ion exchange process possible. The ion exchange resin beads require regular regeneration to allow the process to occur. This requires regular replenishments of salt and water, which becomes waste, leading to higher water bills.

Find out more about how water descalers and water softeners work.

We hope you learned something from our facts on hard water. Remember, when choosing a solution, you should consider the hardness of your water supply. Most areas will be fine with a descaler to prevent scale build-up. Only very hard supplies will require a water softener.