What mainly causes hardness in natural water?
Dissolved calcium and magnesium ions
View source Verified on 16 September 2026
Answered
General Knowledge of Pakistan
Dissolved calcium and magnesium ions
The controlled biological decomposition of organic materials into a nutrient-rich soil amendment
Nitrogen and phosphorus
Excessive nutrient enrichment of water that can cause algal growth and oxygen depletion
It absorbs most of the Sun's harmful ultraviolet-B radiation