From Wikipedia, the free encyclopedia
“A TDS Meter indicates the Total Dissolved Solids (TDS) of a solution, i.e. the concentration of dissolved solids in it. 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. A TDS meter typically displays the TDS in parts per million (ppm). For example, a TDS reading of 1 ppm would indicate there is 1 milligram of dissolved solids in each kilogram of water.”
TDS is a measure of total dissolved solids and NOT dissolved contaminants. A higher TDS can simply be high calcium or mineral content. As Propur® filters are made from minerals, TDS may be higher after the water has been treated. This does not mean the filter isn’t working, it means the TDS meter is picking up the minerals that are naturally released by the filter. A PPM meter is the same as a TDS meter, it is simply measures dissolved solids in water. A TDS meter is not generally recognized in the industry as a proper means of testing water for contaminants. They were created years ago by the manufacturers of reverse osmosis systems as a means of demonstrating the effectiveness of RO which removes most if not all minerals.