High TDS and effect on Chlorine
It is a generally accepted ‘fact’ that high TDS levels suppress the activity of free chlorine. It is not known exactly how, but one theory is that a high level of dissolved solids fills the water with solids that inhibit the movement of sanitizers. Another theory proposes that the particles contained in the TDS measurement are bonding to the chlorine molecule and disrupting normal behavior. Another possibility is that high TDS interferes with testing methods, producing false (low) results during chlorine tests.