Good decision Ruth.

You can buy a simple test instrument that will check to see if there is voltage in the tank. By temporarily unplugging each electronic device, (pump, powerhead etc.) you can find out which one is causing the problem.
Someone with a electronics background please chime in.

I have kept tangs for a few years and find that they do strange things from time to time (like swimming sideways at the water surface). We than become concerned about them and focus on them which in turn stresses them.

If they are eating and have no signs of parasites or other stuff, they are probably OK.

Wayne

Thanks Wayne - yes, other than the occasional hiding everything appears to be fine. At the slightest suggestion of food he is out doing the dominance laps around the tank. Fat and no signs of parasites or other diseases. Still goes into his cave - probably 4 or 5 times a day but other than that nothing in his looks or eating behaviour to give me concern.
We'll see how I make out with the grounding probe. My usual trick is to find stray voltage by sticking my hand in there and realizing that I have been shocked - it is usually as I am about 3 feet in the air and falling backwards at an alarming rate of speed from the chair that I was previously standing on. I hate electric shocks:twised: