Editing Water quality (section)

===Industrial and domestic use===
[[Solvation|Dissolved]] [[ions]] may affect the suitability of water for a range of industrial and domestic purposes. The most familiar of these is probably the presence of [[calcium]] (Ca<sup>2+</sup>) and [[magnesium]] (Mg<sup>2+</sup>) that interfere with the cleaning action of [[soap]], and can form hard [[sulfate]] and soft [[carbonate]] [[Precipitation|deposits]] in water [[heater]]s or [[boiler]]s.<ref>{{cite book |last1=Babbitt |first1=Harold E. |last2=Doland |first2=James J. |title=Water Supply Engineering |date=1949 |publisher=McGraw-Hill |location=New York |asin=B000OORYE2 |page=388}}</ref> Hard water may be softened to remove these ions. The softening process often substitutes [[sodium]] cations.<ref>{{cite book |last1=Linsley |first1=Ray K |last2=Franzini |first2=Joseph B. |title=Water-Resources Engineering |date=1972 |publisher=McGraw-Hill |isbn=0-07-037959-9 |pages=454–456}}</ref> For certain populations, hard water may be preferable to soft water because health problems have been associated with calcium deficiencies and with excess sodium.<ref>WHO (2004). [https://www.who.int/entity/water_sanitation_health/dwq/nutrconsensusrep.pdf "Consensus of the Meeting: Nutrient minerals in drinking-water and the potential health consequences of long-term consumption of demineralized and remineralized and altered mineral content drinking-waters."] ''Rolling Revision of the WHO Guidelines for Drinking-Water Quality (draft).'' From 11–13 November 2003 meeting in Rome, Italy at the WHO European Centre for Environment and Health.</ref> The necessity for additional calcium and magnesium in water depends on the population in question because people generally satisfy their recommended amounts through food.<ref name="WHO DW quality"/>{{rp|99, 115, 377}}