Magnesium
An essential mineral that contributes to water hardness alongside calcium.
Magnesium is the second major contributor to water hardness (after calcium). It dissolves from dolomite, magnesite, and other geological formations.
Why it matters
There is no ADWG health guideline for magnesium, as it is an essential mineral. In water:
- Contributes to water hardness alongside calcium
- Can impart a slightly bitter taste at higher concentrations
- Water with high magnesium relative to calcium may have a laxative effect at very high levels
Typical Australian values
Magnesium levels in Australian drinking water typically range from 1–50 mg/L, depending on the geological source. Bore water and groundwater generally have higher magnesium than surface water.
Check Your Water
See how magnesium levels compare in your suburb with real water quality data.
Disclaimer: Glossary definitions are provided for general educational purposes only and do not constitute medical advice or professional guidance. For specific health concerns about your drinking water, consult a qualified health professional. See our Terms of Use.