Hard water
Water with a high dissolved mineral content — chiefly calcium and magnesium — which reduces detergent effectiveness and leaves limescale and residue on fabric and machines.
What it means
The minerals in hard water react with detergent, so part of the dose is spent softening the water instead of cleaning. Over time this leaves clothes feeling stiff and grey and builds limescale inside the washing machine, shortening its life.
What to do
In a hard-water area, use slightly more detergent or add a water softener or descaler, and run an occasional hot maintenance wash to clear scale. Choosing a detergent formulated for hard water also restores cleaning power without overdosing.
How to use this term
Use this process term when a guide tells you to pretreat, soak, brighten, rinse or adapt a stain method.
- Read hard water with the other symbols on the same care label; the strictest symbol wins.
- Match the instruction to the garment's most fragile part, including trims, lining, prints and finishes.
- If the label, fabric behaviour and stain method disagree, test a hidden area or choose the lower-risk route.
Common mistake
Do not escalate a process before checking the care label and testing a hidden area first.
For the broader method, use the Stain-removal guides and then return to this term when the label changes the safe option.
Related terms
Sources
- Water hardness — United States Geological Survey