Water hardness

Water hardness

Water hardness

The term ''water hardness'' indicates whether there are many or few limescale causing particles in the water. These particles are responsible for the problems regarding limescale deposits in your home.

The water hardness in the United Kingdom is measured in parts per milion (PPM). PPM stands for the amount of calcium carbonate particles in the water.

In England, Scotland and Wales there are a total of 25 water suppliers. Every day, these suppliers deliver millions of liters of tap water to the 28 milion households across the UK. These 25 water suppliers are divided over the different counties and obtain their water from different water sources, such as groundwater and water reservoirs.

This means, that the water hardness in the UK can greatly differ. In some provinces, the water hardness can even differ per zip code. You can find out what your water hardness is after determining your local water supplier. This can be done on the Water UK website. Easily fill in your zip code, obtain the name of your local water supplier, click on the link to their own website and find out your water hardness by entering the term 'water hardness' in the search bar. 


In the UK, the following table is used to determine the water hardness.


German Degrees °D


 0 - 50 0 - 2,8 Soft
51 - 100 2,9 - 5,6 Moderately soft
101 - 150 5,7 - 8,4 Slightly hard
151 - 200 8,5 - 11,2 Moderately hard
201 - 300 11,3 - 16,9 Hard
Over 300 Over 17,0 Very hard

The actual water hardness in the United Kingdom

Unfortunately, many of the water hardness overviews that can be found online are not objective and often spread by commercial companies that support their own interests. At Mediagon Water Treatment, we support transparancy and strive for optimal service. The information above is completely reliable and is publiced by the independent Drinking Water Inspectorate (DWI).

Curious about what you can do against limescale? Check out the options here.