It's not about what the water brings INTO your body, but what it can transport OUT OF the body!

your body, but what it can transport OUT OF
the body!

The more "empty" the water, the more toxins and waste substances it can dissolve (cleanse, detoxify, etc.) and remove from the body. "Empty" means as few dissolved particles as possible in the water.
The amount of dissolved particles is measured by measuring the electrical resistance of the water. When two electrodes are held in the water and current is allowed to flow, the electrical resistance of the water or its conductivity can be determined. The more particles dissolved in the water, the higher the conductivity, more current flows and the resistance drops equivalently. If there are fewer dissolved particles in the water, it works in reverse. The unit of conductivity is called "Siemens" (S), it is measured in Siemens per meter (S/m). The standard unit for freshwater is microSiemens per centimeter (µS/cm). Battery-operated conductivity meters are available for very little money. They have two electrodes on the underside spaced one centimeter apart; you hold the device in a liquid and on a display you can read the conductivity value, that is, the particles per centimeter.

According to Prof. Dr. Louis Claude Vincent (University of Paris), the optimal resistance value for our drinking water is below 130 µS (MicroSiemens). The water is noticeably soft and has a high cleansing effect in our body.
Already at saturation (contamination) of 280-499 µS, the water has a burdening effect on the body. A value that is too high introduces more foreign substances into the body than are transported away.
Pure "empty" water allows nutrient ions to pass through better and can transport pollutants and acids (waste products) away faster (detoxify).
See the following table of legal limit values and a scale by Prof. Vincent on the effect of "empty" water on the organism: