Find out what hard water is and why it's causing limescale and any other problems throughout your home.
What is hard water?
Hard water is the name given to water which contains magnesium and calcium minerals. Hard water becomes such when rainwater, which is naturally soft, falls on porous ground, such as limestone or chalk. As the rainwater penetrates the porous ground, it picks up the magnesium and calcium particles along the way, which it retains once it gets to the reservoir and when it enters your home.
There are many effects of hard water, the majority of which are detrimental to your home. Due to the mineral content of hard water, it creates limescale build up in your home which makes it appear unclean and clogs up shower heads and even corrodes the inside of your appliances, reducing their efficiency and lifespan.
The composition of hard water means that it is also damaging to the natural layer that protects your skin, and some studies have shown that there is a correlation between hard water and dry skin conditions like eczema.
Hard water and the water cycle
To understand how hard water is created, we need to find remind ourselves of the water cycle and how naturally soft rainwater falls to earth.
The image shows how the water cycle works. To summarise; the sun heats water, which in turn evaporates into water vapour. Water vapour rises into the air, where it eventually cools and condenses into clouds. The clouds will be transported long distances and will eventually break apart forming precipitation or rainfall. Water collects on the ground, rivers, lakes and oceans, where the sun will heat it up once again, starting the process all over again.
The evaporation process means that only pure water is drawn up to become clouds - and therefore all water that falls from the clouds in the form of rain is pure and free of mineral content - we call this soft water.
It is only when that water reaches the ground that it starts to pick up hardness minerals.
The effects of hard water
The negative effects of hard water come in the form of scale and scum. You may be familiar with the telltale signs: white marks around baths and basins often coupled with unsightly white marks on sinks, toilet bowls and shower heads. In worst case scenarios, the build up of limescale can create blockages in pipework and lead to the premature failure of water heaters and other appliances.
Due to its composition, hard water also has difficulty making a lather when combined with soap, resulting in a less than effective wash. Clothes can be left grey and dingy, whilst dishes and glasses can appear dull and smeared. For a full breakdown of the issues hard water causes, check out our comprehensive guide on hard water problems.
Your hair can also be affected by hard water, leaving it dull and difficult to manage. Find out more about hard water hair and how to treat it, here.
Water hardness in the UK
Hard water is only created in areas where the pure rainwater comes into contact with porous ground. This means that there are some areas of the UK where water is much harder than others, though the majority of the country suffers to an extent.
The map shows the prevalence of hard water across the UK.
The link between hard water and eczema
In a recent study carried out by the University of Sheffield about the effects of water on eczema, it was found that hard water (as opposed to soft water) aggravates skin conditions and can trigger flare-ups. They also discovered that hard water creates an irritable skin barrier that can cause eczema in healthy skin. The study also showed that some people are genetically more prone to developing eczema, regardless of any existing eczema condition.