I just posted this because I think it is important to have a grounding rod. If you think about the amount of electrical components in our systems the chance of having one fail at one point or another is definitely a possibility. Some fail but not not completely and just bleed voltage into the tank which is not good for fish or corals. The worst would be if one component had shorted and was just sitting there waiting for you to put your hand in the sump or tank and complete the circuit.