Feb 07, 2019 · “Potable water” simply means water that is safe to drink, and it is becoming scarcer in the world. Increasing use is stressing freshwater resources worldwide, and a seemingly endless list of contaminants can turn once potable water into a health hazard or simply make it unacceptable aesthetically. Aug 19, 2009 · I would suggest buying a small packet of PH solution of 7.0, they are cheap. Calibrate your meter with the solution, and test your distilled water. It should be 7.0.. but check it anyway.. I got some water, for the same reason, and it tested 9.0. And yes, it was "distilled" water before anyone asks, not spring or natural or any of that. Deionized pure water is a poor electrical conductor, having a resistivity of 18.2 million ohm-cm (18.2 megohm) and conductivity of 0.055 microsiemens. It is the amount of ionized substances (or salts) dissolved in the water which determines water's ability to conduct electricity. Demineralized water, on the other hand, most assuredly is corrosive, and will happily dissolve whatever it is in contact with until the dissolved solids level reaches an equilibrium. Now as I say, if you aren't adding much water to your system, that level is low enough that you won't see that much corrosion.