Hard water vs soft water: what the difference means
Hardness describes dissolved calcium and magnesium. It is useful for understanding limescale and appliance settings, but is not an overall water-quality score.
What you may notice at home
Hard water can leave mineral scale in kettles and hot-water appliances and produces less lather with soap. Local geology affects hardness, and values can vary within a region.
Read the number as well as the label
DWI describes water up to 100 mg/l as calcium carbonate as soft; above 100 to 150 as slightly hard; above 150 to 200 as moderately hard; above 200 to 300 as hard; and above 300 as very hard. Check the units before comparing two reports.
Choose practical steps for your household
Use your appliance manual for maintenance and hardness settings. Many dishwashers have a built-in softener and require the correct salt and settings. A domestic softener is a separate installation: ask a qualified installer about suitability and follow supplier guidance on retaining an unsoftened drinking-water tap.
Check your published area information
Sources and review
Sources checked 6 September 2026. Prepared by WaterGrade.
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