Ron, anytime you dip a cut finger in SALTwater you'll feel a buzz voltage or not
Have you tried unplugging each electrical device one by one with the multimeter in the tank to see if you get any variance?
FWIW I run the gamut of ZEO additives (incl. AA and LPS AA) except for the actual main ZEO system (go figure) and found that less is more - i.e. you need very little; anything approaching the max dosages on the bottles leads to an algae bloom.