how did you measure it War?
I have picked up a 185 mV (0.18 V) DC in my water column. I am battling to work out what is causing it. ?
First suspect : pumps and power heads, second: fluorescent lights.
Check your AC voltage, it's possibly much higher...
Hennie
Cannot get an AC reading, either the meter can't go low enough or it ain't there.
I have tested lights and pumps individually.
Would an inverter be a possible cause ?
You can't really just test like that, as its measuring the potential differance between the 2 probes in the water only, Try do a test by placing 1 probe in the water and the other on somehing that is earthed, perhaps the aluminium cover of a lighting hood (If you know its earthed)..... then you will start getting some true results....
BUT BE CAREFULL
OK, I have done it and I get a lower reading - 50 mV
That shouldn't be problem, in other words, if you are standing on the floor bare foot with a hand in the tank, a voltage of 50mv would pass through your body if you were made out of a conductor like copper, but you not, so only a fraction of the 50mv will pass through you. you should be safe.
How could one earth the water incase there is an earth leakage. We cant put copper in the tank.
IIRC titanium bicycle spokes can also work well as a tank earther. But rather find the source of the leakage and stop it, a big (electrical) current in the tank can cause problems in fish, especially tangs (lateral line erosion)
How do you earth the 2 pin plugs. My pumps are all 2 pins, my heater, just about everything actually.