Functionality

Total Dissolved Solids. TDS in water refers to the amount of total dissolved solids in your tap water. After water falls to the ground as rain, it dissolves the minerals present in the rocks and soil it passes over or through. As it dissolves these minerals, they remain in the water at varying levels of concentration. This is a very natural process and it helps make water taste “right” by slightly raising the pH of the water. The most common minerals found in water are calcium, magnesium, and sodium.

A TDS meter is a small hand-held device used to indicate the Total Dissolved Solids in a solution, usually water. Since dissolved ionized solids, such as salts and minerals, increase the conductivity of a solution, a TDS meter measures the conductivity of the solution and estimates the TDS from that reading.

TDS meters may be referred to as TDS testers or PPM (parts per million) testers, but all of these are different names for the same thing. TDS meters can be purchased for as low as $10, but more advanced models can cost $1,000+ based on the level of accuracy and additional features offered.

For example, a basic TDS meter may only measure the amount of total dissolved solids in a solution while an advanced model may be able to check salinity, temperature, and more.