One of the first principles taught by Dr McDaniel is consuming "good" water, meaning distilled or reverse osmosis (R/O) water (mineral free water). "The biggest pollution is in what you drink" says Dr McDaniel. The TDS (Total Dissolved Solids) meter will measure the "solids" in the water you consume.
Test your city tap water, bottled water or any commercial water you consume. The water should be under 10 on the TDS meter, meaning under 10 parts per million. The closer to zero on the TDS meter the better, meaning less dissolved solids. Total dissolved solids is a measure of the dissolved combined content of all inorganic and organic substances present in liquid in molecular, ionized or micro-granular suspended form.
Some of the unacceptable solids are aluminum, lead, mercury, copper, tin, zinc, cadmium (well, you get the idea!) You don't want any of these in your drinking water. Make sure the water you drink, make coffee, teas, rice, soups, pastas and any other water added to cooking, is under 10 TDS.