What is hard water and do I have it?

Approximately 60% of homes are supplied with hard water. In the north and west of the UK the water is naturally soft, wheras in the south and east it is naturally hard.

It is the dissolved minerals in hard water that gives it the following characteristics:

• Scale and scum formation. For example, either on the surface of the water or round hand basins and baths.
• Difficulty in getting a soapy lather. This is caused by the calcium in the hard water reacting with soaps and detergents. 

The minerals that contribute to water hardness are calcium and magnesium, mainly in combination with bicarbonate, sulphate and chloride. When hard water is heated above 61 degrees (or as it evaporates) the balance between the dissolved minerals is upset and the bicarbonate converts to carbonate. This is where you get the calcium carbonate scale!

Hardness is measured in mg/1 or ppm (parts per million) of calcium carbonate equivalent (the main component of scale). The word equivalent is used to show that it is not calcium carbonate that is being measured (it cannot be as calcium carbonate is not present in water) but that the amount of different hardness minerals present in the water is chemically equivalent to an amount of calcium carbonate.