Just to take this conversation a bit more....a grounding probe without GFCI is of no safety to your tank. Without the GFCI, and you now have a voltage leak, you now have current. And current is the killer. Without the GFCI, you'll never know when you're electrocuting your tank. A GFCI will detect this current and pop the breaker. It's the combination of the two that protects both you and your fish.
Now, with that said, I do not use a grounding probe. The reason is that I want to feel that tingle to know I have a voltage leak problem. If I were to use the recommended GFCI and grounding probe, my concern is that it will pop at the most inconvenient moment....when I'm on vacation....leaving my tank with no electricity. So I'll stick with the tingle....gosh, I've been zapped enough doing electrical work.....the tingle is nothing!
My recommendation is to do what you feel comfortable doing....nothing or GFCI with probe....whatever floats your boat.
Now, with that said, I do not use a grounding probe. The reason is that I want to feel that tingle to know I have a voltage leak problem. If I were to use the recommended GFCI and grounding probe, my concern is that it will pop at the most inconvenient moment....when I'm on vacation....leaving my tank with no electricity. So I'll stick with the tingle....gosh, I've been zapped enough doing electrical work.....the tingle is nothing!
My recommendation is to do what you feel comfortable doing....nothing or GFCI with probe....whatever floats your boat.