stray current-ground or no ground

[salty joe]

I thought about this last night while drifting off to sleep. My take on a ground probe is, it makes it safer for the aquarist but more dangerous for the tank inhabitants.

Safer for the aquarist is obvious, a ground probe gives the stray electricity somewhere to go besides through your body.

More dangerous for the tank inhabitants because a ground probe completes the circuit and now electricity is flowing through the tank as well as the animals in the tank.

My final thought is, the best thing would be a tank run solely on DC current no higher than 24V and no ground probe. The typical amperage used in fish tank stuff is no more than 2A. I don't think that's very hazardous.

That's not to say stray DC voltage shouldn't be tracked down and fixed.

If I'm wrong, please correct me.

 

[ZoWhat]

"completes the circuit" ......but not at 100% unless the fish has the ability to touch the faulty electric with one fin and the probe with the other fin.

99% of that "completed circuit" across the tank is lost to attenuation.

correct me if i'm wrong....

 

[Greybeard]

IMHO: Current leaks are bad. Find 'em. Fix 'em. Even if you never get zapped, there's no way that electricity is 'leaking' without there being an exposed electrical component somewhere... corroding. See? Bad.

Plug a ground probe in, make sure all of your electrical components are attached to a GFCI circuit, and presto... if something is 'leaking' electricity, it shuts off... alerting you that you've got a problem.

This is one of those things I wouldn't have suspected that ANYONE would disagree with, but... based on previous threads regarding GFCI and ground probes, I would have been incorrect. There are people who have some sort of problem with them... justification ranges from a GFCI outlet tripping without cause (which a properly wired GFCI circuit in good condition doesn't do), to the above... with a ground, the tank doesn't just have electrical potential, but actual current. Both ignore the fact that COPPER IS BAD in a reef aquarium. Metal corrosion is BAD. I want to do everything in my power to keep from having an exposed electrical component in my tank, and if I do have one, I want to know about it.

 

[salty joe]

Makes sense what you say about attenuation skimjim, but I don't know for sure.
Greybeard, an exposed wire is the most compelling reason I've heard for a GFCI in my situation (100% DC where my safety isn't a concern).

I realize a GFCI shouldn't nuisance trip, I also realize they sometimes do. I don't use GFCIs because of that but you make a great point.

Thanks for the ground probe/GFCI test. It took a quick minute to nail it down to the algae filter lights. I'm not worried about metal getting in the tank from the AF lights but will certainly find and kill the stray current.

So, since I don't need a ground probe for my safety and I don't plan on using GFCIs to indicate faulty equipment (might rethink that one...) is there a good reason for me to have a grounding probe?

 

[ZoWhat]

Usually the culprit is a powerhead

The electric motor is sealed in glass but over continuous heating and cooling cycles.....MICROCRACKS form in the glass seal, exposing just enough amperage to tingle your fingers

Left unchecked it will only get worse until the powerhead gets cooked...then the powerhead stops working bc the AC circuitry gets detached due to electrical damage