Today I had a very small cut on my finger,it caused my finger to be extra sensative and when my finger touched the water and my light at the same time, I felt a very small current. Now my light rests on my tank against the plastic supports. I figured the electricity was coming from light and due to dampness of aquarium, was conducting it's way to the water. So I shut off light and touched water and light, it still did it. So I figured it had to either be one of my 2 powerheads or heater. So I unplugged 1 powerhead and it stopped. I plugged it back in and I felt it. I thought case solved but I then unpluged 2nd powerhead and it stopped.I plugged it back in and it started. I then left those plugged in and unplugged the heater and again it stopped. It seems as if it didn't matter which one I unplugged ,as long as I unplugged something. Is it that I have too many things plugged in the powerstrip? I don't think so, but I can'texplain it any other way and I'm far from being an electrcian. PLEASE HELP.