The water that lathers with soap easily is called soft water. It describes type of water that contain few or no minerals like calcium (Ca) or magnesium (Mg) ions. The term is usually relative to hard water, which does contain significant amounts of such ions.
Hard water may be better for the heart than soft water. Its calcium (Ca) and magnesium (Mg)ions may be a dietary supplement for some.
The main disadvantage of hard water is it deposits calcium carbonate on pipes, especially hot water pipes. This is called "scale formation". It may cause blockage of pipes and reduce boiler efficiency. Also, soap and detergents work less well in hard water. These effects increase as hardness increases.
References[change | change source]
- Section 36 "Hardness" https://www.epa.ie/pubs/advice/water/quality/Water_Quality.pdf