Total Dissolved Solids (TDS)
The total concentration of all dissolved minerals, salts, and organic matter in water.
ADWG Guideline
600 mg/L
Total Dissolved Solids (TDS) is the sum of all dissolved substances in water — minerals like calcium, magnesium, sodium, potassium, and bicarbonates, as well as trace amounts of organic matter.
Why it matters
The ADWG sets a guideline of 600 mg/L for aesthetic quality. TDS affects:
- Taste: Water below 300 mg/L is generally rated as excellent taste. Above 600 mg/L may taste salty or bitter.
- Scale and corrosion: High TDS can increase mineral deposits in plumbing and appliances.
- No direct health risk at typical Australian levels, though very high TDS may indicate the presence of specific problematic minerals.
Typical Australian values
Urban treated water typically has TDS between 100–500 mg/L. Bore water can exceed 1,000 mg/L, especially in arid regions.
How it’s measured
TDS is measured by evaporating a water sample and weighing the residue, or estimated from conductivity readings.
Related Terms
Check Your Water
See how total dissolved solids (tds) 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.