We had done some investigation on this subject, and the main affect was to the lateral line of fish (the research was on the effect of not grounding).

This LL is what a fish uses to sample for microvoltages caused when organic life moves. There is a small microvoltage emmited by muscle contraction. The fish can use this to alert them to the presence of predators coming into the area.

The current is not what is sampled for, but voltage alone.

The induced voltages from any submerged coil device ie: powerhead, heater, pump, and the aura from FL can all add voltage to the tank.

This voltage plays havok with the LL in that it is always being assualted. Imagine if you will being hooked up to a galvenometer for extended periods. Or using a vibrating sander, it doesn't hurt, but it gets annoying after a while.

The LL is designed to receive microvolts, and with it being constantly fed say 50V., you can imagine the net result.

Grounding just returns the fish to their normal environment as the ocean is always at ground state. Hope this answered your question.

From an exchange on our lists 5/12/97