• Make sure you choose a detergent that is suitable for the fabrics, soiling and colours in your wash load: detergents are available especially for your machine type, water temperature and fabric type. Click for tips on choosing a laundry detergent.

  • Follow the dosage instructions on the package as a guide. Take into consideration:

    • Water hardness: more detergent if the water is hard.

    • Wash load size: more detergent if you have a large capacity machine.

    • Wash load soiling: more detergent if you have a heavily soiled load.

UNDERDOSING could lead to incomplete soil removal, or transfer of dirt from heavily soiled items onto other items (“greying”).

OVERDOSING is wasteful of detergent, adds unnecessarily to the levels of detergent ingredients in wastewater, and can lead to detergent residue on clothes.

What is water hardness?

Water hardness is a measure of dissolved calcium and magnesium in water (in milligrams per litre). A simple test of water hardness is to see how well a lather forms. Add some detergent to the water and agitate. Lather will form easily in soft water but not in hard.


Water hardness depends on the source of the water:

  • Rainwater is very soft.

  • Bore water is typically hard, but varies around the country.

  • Reticulated water varies around the country. Typical levels of water hardness in major cities are shown below. Your local water authority may be able to give you more information on water hardness in your local area.