The higher the TDS, the more minerals, salts, or other dissolved substances are in the water.
You can also read about how to measure TDS (laboratory approach).

How to measure at home:

• Rinse the TDS meter electrode with clean water.
• Immerse the device in the water you want to test, ensuring the sensors are fully covered.
• Keep the meter still until the reading stabilizes (usually 10–30 seconds).
• Pay attention to the water temperature — some meters automatically compensate for it.

Calibration:

• Before measuring, make sure the device is calibrated.
• For home use, factory calibration is usually sufficient, but you can buy standard solutions with known values and check the meter in them.

What the readings mean:

• TDS is measured in ppm (parts per million).
• Low TDS (<100 ppm) — soft water.
• Medium TDS (100–500 ppm) — typical drinking water.
• High TDS (>500 ppm) — may taste unpleasant and is not recommended for drinking.

Tips for accuracy:

• Measure water at room temperature.
• Try to avoid creating air bubbles on the sensor.
• Repeat the measurement several times and take the average.
• Clean the sensor regularly.

Important:

For home use, a TDS meter provides approximate information about water quality but does not replace a laboratory analysis for harmful chemicals or microbes.