I have a question, I have 2 grounding probes and when the electrician was here doing
some work, I asked him about the testing, that is mentioned in the instructions. He had
no idea what it was talking about. So they are still sitting in the closet. Iam also a bit
confused as how they could zap the fish. Do they absorb stray voltage, Iam confused.
Please explain for us dumbies.

They complete the circuit- so if there is stray voltage, it flows through your tank. You stay safe, because you can't ground the tank yourself anymore, but the current still flows through the water. It's not as dangerous to fish as it is to humans, but it causes their navigation systems to go berserk. Messes around with the sensory pits in the lateral line, if I recollect correctly.
With a GFI, on the other hand, as soon as leaking electricity is detected, it shuts down the circuit. No damage. Of course, then you have to start testing to figure out which piece of equipment is leaking... which could be a PITA. But still better than taking a risk, IMO.

So if you have a GFI, then you do not need a grounding probe?

A couple of dumb questions.

1. Should you have a probe in both the sump and the aquarium?
2. Can you not make your own ground probe with a piece of insulated copper or aluminum wire?

Never used one. Never needed one. If you've got "stray voltage", then fix the equipment that is causing it. Further, a GFCI will save your life, a ground probe will not.

As I posted, why not use both. I would never run with no GFI, but I do on occasion have something run to another plug for whatever reason. In my particular situation, no probe, arc to my forehead, probe in, no problems.

As for fixing the pump, thats all fine and dandy, once you know its screwed and leaking current.

There is a decent size thread about ground probes being very dangerous on RC.

My 2 cents...I have one in my sump, i have a gfi as well. The other nite hands were in the tank and i got a good jolt and then gfi tripped. It was my light, and about a year ago i was shocked by the same light and didnt have a gfi installed. Talk about being electrocuted!! Especially when one arm is all the way to the bottom of a 24" tank!!!

Not sure what the ground probe does, or if its worthwhile, but i know i love my gfi now!!

The general consensus is that if you run a ground probe you MUST also run a GFCI otherwise you are actually putting yourself at GREATER risk by having a ground probe without a GFCI because nothing will trip to shut down the offending electrical component should it actually be leaking current (to you for example).

Also, the fish don't get zapped. They aren't grounded. The idea that stray current somehow causes HLLE has generally been dismissed as nonsense over the last few years.

Do a search on RC - this has been debated ad nauseum and when people who actually know what they are talking about (I'm certainly not one of them) get involved in the conversation the take home message becomes the same - if you run a grounding probe you must also run a GFCI for your safety.

That is an intersting point that the fish are not grounded. I never thought about that, I always assumed that if I saw fish floating belly up I would know not to stick my hands in.

I really need to get a GFCI. I need to find someone in Calgary that can do it for me.

To be fair, I don't know how realistic an inference it is to suggest that because the fish isn't grounded that it wouldn't some how be effected by stray voltage. I've seen it suggested that because the fish aren't grounded they aren't at much risk, but when I think about it intuitively I would assume that if I cut the cables on one of my powerheads and stuck the wires in the tank next to a fish it would presumably show some kind of distress (but as I mentioned above I'm not really qualified to comment on electricity because I'm completely ignorant about its effects beyond what we use therapeutically in physiotherapy).