Water quality and your appliances

Water hardness is an indicator of the ability to obtain a lather using soap, whereby hard water is more difficult to lather than soft water. Hardness is affected by calcium and magnesium salt content.

Different manufacturers of household appliances may refer to water hardness within instruction manuals due to the effect on the performance of equipment.

In Australia, water hardness is measured as the concentration of calcium carbonate (CaCO3) in units of milligrams per litre (mg/L).

Canberra’s water is defined as soft, containing approximately 41 mg/L CaCO3*.

Refer to the table below for common conversions of this water hardness figure across different manufacturers’ settings.

Country of manufacture

Other methods of measurement

Unit of measurement

Australia (mg/L)

USA (ppm)

Germany (°d)

England (°e)

France (°f)

International Unit (mmol/L)

Physical Unit (mval/L)

Average hardness level for Icon Water customers








*based on 2018-19 data