WaterFuture - Get into water

Do you have hard water?

Rainwater is naturally soft as it contains only small amounts of minerals.

As the water passes through limestone and sandstone rocks, minerals (calcium or magnesium carbonate) in the rocks are dissolved in the water, making it hard.

Most of our water supply can be classified as ‘moderately hard’ (on a scale of one to ten this would be seven).

For more information on water hardness and test results from customers’ taps in your area, please use this postcode search.

The Total Hardness Level is 270 mg per litre as Calcium Carbonate (CaCO3).  This is equivalent to:

PPM (parts per million)


Clarke Degrees

French Degrees

German Degrees






Supplies north of Ringwood receive a slightly higher hardness level of 320 mg/l as CaCO3. This is equivalent to:

PPM< (parts per million)

Clarke Degrees

French Degrees

German Degrees






If your water is classed as hard, you may choose to install water softeners in your home. However the Drinking Water Inspectorate recommends you don’t soften the water supply used for drinking water because it can increase the levels of sodium which is harmful if you have high blood pressure. It can also be more corrosive to metal pipework which leads to higher concentrations of metal in the water.

What water hardness can mean for appliances and items within your home


Soft water areas

Hard water areas


No special requirements

May discolour over time

Avoid re-boiling the same water to reduce limescale build-up.

Boilers and central heating systems

No special requirements

Set the boiler to 60-63 degrees to avoid limescale.


No special requirements

Use the lowest appropriate tempera­ture to reduce limescale build-up.

Washing machines

Use the lower amounts of washing powders and fabric conditioners rec­ommended by manufacturers

May need more powder and condi­tioners. Limescale may build up over time.

Soap and washing-up liquid

Small amounts needed

May take longer and more to build up a lather.


Use the lower settings recommended by manufacturers

Use the higher settings for softening as recommended by the manufac­turer. Consider using salt tablets.

Baths and fittings

No special requirements

Limescale likely to build up and may require regular use of anti-limescale cleaners


Softening treatments

Domestic treatments such as jug filters, water softeners or conditioners all have pros and cons.

Jug filters

Jug filters are jugs that have a replaceable cartridge housed in a unit that fits on top. The two main types of cartridge available have either:

  • an activated carbon media designed to remove chlorine and organics, or
  • an ion exchange resin media designed to soften the water

The carbon cartridges don't chemically alter the nature of the water but simply absorb things like chlorine. If you find black deposits in the water or the top of the jug, they will most likely have come from these cartridges, rather than our water supply.

The ion exchange softening cartridges chemically remove the calcium and magnesium salts in the water and replace them with sodium. For this reason, we advise against using this water for drinking for people on low sodium diets. We also advise against using this water for making up infant feeds. These cartridges may leave orange or white particles in the water.

It’s important to maintain and replace both types of filters in accordance with the manufacturer’s instructions. Old filters can cause a build-up of particles and encourage bacterial growth, which contaminates the water. Filtered water should be drunk soon after pouring, as water with the chlorine removed has no protection against the growth of bacteria.

Water softeners

These plumbed-in devices use salt to soften the water by removing the hardness salts (calcium and magnesium) and replacing them with sodium.

We strongly advise keeping a separate tap for un-softened water for drinking as water softened this way can contain higher levels of sodium, which is not recommended for people on low sodium diets, or for making infant feeds. It has also been suggested that people who consume softened water may suffer a higher incidence of heart disease.

Softened water is a lot more aggressive towards metal fittings. You may experience higher corrosion of pipework, and if a softening system is fitted to an older system there is a greater risk of pinhole leaking once the protective hardness layer has been removed.

Water conditioners

These devices are attached to the outside of water pipes. They do not alter the chemical composition of water, but impart some form of electric or magnetic field into the water as it passes through. In theory, this changes the crystalline structure of the hardness salts so that a hard limescale does not build up.

Despite manufacturers’ claims, it has not been possible to find a unit that works in all circumstances. If you wish to try one, choose a manufacturer that offers a full refund after a reasonable trial period in case you are not satisfied.