REFERENCE
Simple water tools
Look up common ranges. These are teaching aids, not a substitute for a certified lab or a utility report.
TDS reading helper
Enter a pocket-meter TDS value (mg/L). This only classifies the number — it cannot say if water is safe.
Hardness scale (as CaCO₃)
Enter hardness in mg/L as CaCO₃ if your report uses that unit.
Ranges are simplified teaching bands used in many educational texts. Labs and countries use different cut-offs. For drinking decisions use a certified test. Privacy.