Originally Posted by
capttommy
http:///forum/post/2612734
The best way that I found to test voltage in an aquarium is to put the multi meter on 200 volts. Put one of the leads in the round grounding hole on a plug. Be careful there is voltage in the plug. The other lead should be in the water. You will need to be sure the probe is firmly touching the metal in the grounding hole of the plug. Last week I had a pump start putting voltage in the tank and this technique showed 23 volts. All fixed and grounded now.
I may get overruled by SCSI or someone, but I usually prefer to start on the lowest voltage reading and work up. There was a thread a month or so ago where a guy was pulling his hair out b/c of voltages until someone pointed out he was on 200V instead of lower. Lowered the range, and found he only had a few mV, which is nothing to worry about.