I've been using a ground probe ever since I got a little shock from my tank one day feeding my Stonefish. One of my pumps was sending a small current through my tank. I think the cord was loose in the housing or something, but the grounding probe seem to work. I have also been told (don't know if it's true), but too many electric units, pumps, powerheads, will sometime bleed a little current into your tank affecting the fishes lateral line movement. Meaning, they do not all move together, some even seem confused moving about all willy-nilly.. I guess it's just a matter of preference. Bang, or Broomer, one the top-dogs should be able to explain it better..