What Is a TDS Meter? How It Works and Its Functions

A TDS meter is a device used to measure the total amount of dissolved solids (Total Dissolved Solids) in water. The TDS value indicates the level of water purity and is very important for drinking water, aquariums, hydroponics, and industrial use.

What Is TDS?

TDS, or Total Dissolved Solids, refers to the total amount of organic and inorganic solids dissolved in water, such as minerals, salts, heavy metals, and other ions. TDS is usually measured in ppm (parts per million).

Functions of a TDS Meter

• Determine the purity of drinking water or RO (Reverse Osmosis) water

• Check the quality of well water, municipal water, or bottled refills

• Monitor nutrient levels in hydroponic systems and aquariums

• Identify when water filters need to be replaced

How a TDS Meter Works

A TDS meter works by measuring the electrical conductivity of water. Since dissolved substances conduct electricity, the higher the TDS content, the higher the conductivity value.

This tool is usually shaped like a pen. You simply dip it into the water, and the result will be displayed on the digital screen in ppm units.

TDS Reading Guide

How to Use a TDS Meter

1. Prepare a clean glass and fill it with the water to be tested

2. Turn on the TDS meter

3. Dip the probe into the water up to the indicated level

4. Wait a few seconds until the reading stabilizes

5. Read or note the displayed value (ppm)

6. Rinse the probe with clean water after use

Tips for Optimal Use

• Use a non-metal container for testing

• Do not measure hot water, as it may damage the sensor

• Calibrate the TDS meter periodically for accuracy

A TDS meter is highly useful for monitoring water purity and quality. By understanding how to read the results and knowing the ideal values, you can ensure the water you use is safe and suitable for your needs. This device is practical, affordable, and essential for anyone using water filters, RO systems, water treatment plants, or hydroponics systems.