The TOTAL SALT CONTENT (GSG) is the sum of the ions dissolved in water. Wait a minute, didn't we just have that? Be careful, when it comes to the total hardness, we only referred to the alkaline earth ions, but the TOTAL SALT CONTENT includes all ions, including sodium and chloride ions, which together produce table salt. You can roughly estimate the TOTAL SALT CONTENT using an electrical conductivity measurement, which, however, only helps to a limited extent, as you can neither infer the exact concentration nor the composition of the salts. Nonetheless, this measurement is important because the capacity of an ion exchanger or the performance of a reverse osmosis system depends on the TOTAL SALT CONTENT.