Using Ground Probes in Aquariums

[Brew12]

Yes:)

If your heater is grounding your tank water properly it should be under 5V. If its not, you might need a separate probe.

 

[jsker]

If your heater is grounding your tank water properly it should be under 5V. If its not, you might need a separate probe.

Were would on find a simple, how to test for stray voltage?

 

[Brew12]

Were would on find a simple, how to test for stray voltage?

If you have a volt meter, make sure you have it set to test for AC volts, put one lead in the water and the other lead in the round ground slot on an outlet.

 

[DocPaulo]

Not a physicist but my understanding of the faraday cage is that it helps protect living organisms from electrocution...

Saltwater has high conductivity and acts as a faraday cage of sorts for the fish.. they may still be getting irritated by it but prob not lethal...

Any physicists here?

 

[Chrisss]

Grounding probe fixed my voltage leak in my tank. I would put my hand in the tank and get shocked on the cuts of my hands for about a 1 week, after I installing a grounding probe its been fine and reading a ~0.3 or less and no shock :D

Best and cheap fix and been solid for 2 years now and still no shocks!

 

[CDavmd]

Great article. So I have a peculiar situation. I have a 24x24 acrylic frag tank in my basement. It is not a heavy duty gladiator work table (wood top, steel legs). The basement is unfinished and concrete floor. I have a gyre and ecotech vortech in the tank. There is a sump underneath that sits on a rubber floor pad. Two heaters, skimmer, and For-15 pump. I also have a power strip screwed to the underside where I connect my Kessel light which hangs over the refugium portion. I do have power cables all running under and along the side of the table to an Apex EB832. It is powered through a long extension cord to an outlet.

I have noticed intermittently that when I am in my socks standing on the concrete and I go to grab a frag in the water that I will feel a sting if I have a cut on my fingers. Sometimes its very mild, other times very uncomfortable. I have unplugged everything and it still remains when its present. I am not sure if it is induced but my suspicion is that it is.

I purchased a titanium grounding probe and placed it in the sump and plugged it in to an outlet with an extension cord so it could reach. I still felt the electricity. I tried placing it in the display and still present. I tried unplugging everything from the EB832 with the ground probe in the water and I still feel it???!! I am at a complete loss. If I stand on some rubber matting, it is markedly reduced to absent.

Any ideas?

Thanks for your help.

 

[theMeat]

Ground probe should be paired with a gfci outlet.
Does the extension cord you are using have a functioning ground wire? How bout the outlet you’re plugged into?

 

[CDavmd]

Ground probe should be paired with a gfci outlet.
Does the extension cord you are using have a functioning ground wire? How bout the outlet you’re plugged into?

Thanks for the reply- yes the extension cord has a ground wire but the outlet is not GFCI. I do not have any GFCI outlets in my basement- I guess I will need to have one installed.

 

[Brew12]

I purchased a titanium grounding probe and placed it in the sump and plugged it in to an outlet with an extension cord so it could reach. I still felt the electricity. I tried placing it in the display and still present. I tried unplugging everything from the EB832 with the ground probe in the water and I still feel it???!! I am at a complete loss. If I stand on some rubber matting, it is markedly reduced to absent.

That is definitely an interesting situation. It sounds like the voltage source may be the concrete itself. Concrete is a fairly good conductor of electricity.

It's not a great test, but I have an idea on how to check. With the ground probe plugged in, hold the titanium part in your hand. It may help to have your had a little wet with salt water. With that same hand, extend a finger into your frag tank (without letting the probe in that hand touch the water) and see if you get a tingle. For safety reasons you don't want to hold the probe in one hand and touch anything with the other.

Thanks for the reply- yes the extension cord has a ground wire but the outlet is not GFCI. I do not have any GFCI outlets in my basement- I guess I will need to have one installed.

If you aren't comfortable switching an outlet to GFCI yourself, you can get something like this to plug into the wall.
https://www.lowes.com/pd/Tower-Manu...ngle-to-Single-Yellow-Gfci-Adapter/1000492081

 

[CDavmd]

That is definitely an interesting situation. It sounds like the voltage source may be the concrete itself. Concrete is a fairly good conductor of electricity.

It's not a great test, but I have an idea on how to check. With the ground probe plugged in, hold the titanium part in your hand. It may help to have your had a little wet with salt water. With that same hand, extend a finger into your frag tank (without letting the probe in that hand touch the water) and see if you get a tingle. For safety reasons you don't want to hold the probe in one hand and touch anything with the other.


If you aren't comfortable switching an outlet to GFCI yourself, you can get something like this to plug into the wall.
https://www.lowes.com/pd/Tower-Manu...ngle-to-Single-Yellow-Gfci-Adapter/1000492081

Thanks!

So i was able to run an extension from a GFCI circuit to the Frag system energy bar. I have the ground probe in the sump.

What’s interesting is I was under the tank working in the sump (after GFCI and ground probe setup) had my right hand on the concrete and the other in the sump and felt the current.

I’m going to try what you suggested and report back...

 

[Sump Crab]

So I decided to put in a ground probe and now I can feel electrical current when I reach into the tank. When I take the probe out I can no longer feel the electricity when I put my arms back in. What should I do now? Thanks!

 

[theMeat]

Is the ground probe plugged into. gfci outlet?

 

[vetteguy53081]

So I decided to put in a ground probe and now I can feel electrical current when I reach into the tank. When I take the probe out I can no longer feel the electricity when I put my arms back in. What should I do now? Thanks!

That is weird as it is doing the opposite of its purpose. It is important that the ground wire is actually grounded to receptacle and not attached to any LIVE source.

 

[Sump Crab]

That is weird as it is doing the opposite of its purpose. It is important that the ground wire is actually grounded to receptacle and not attached to any LIVE source.

I had it attached to my power strip, is that incorrect?

 

[Sump Crab]

Is the ground probe plugged into. gfci outlet?

No, it was plugged into my powerstrip

 

[vetteguy53081]

I had it attached to my power strip, is that incorrect?

No- has to be plugged directly into a receptacle

 

[theMeat]

I had it attached to my power strip, is that incorrect?

Stray voltage without a ground probe is bad. You will have to be grounded for you to feel that stray voltage.
Stray voltage with a ground probe is arguably worse, because it gives the current a place to go. Another words completes the circuit, you won’t need to be grounded to feel it, simply touch the water, and your fish feel it too
A ground probe plugged into a gfci outlet is the only way to go.
With a ground probe into a regular outlet you will need, around, the amperage that the breaker is rated for to trip. Another words 20 amps for a 20 amp breaker, etc. That’s a lot of power to get zapped with in water.
With ground probe plugged into gfci, a very slight fluctuation in ground will trip it. You might not even feel it.

Gfci will trip with stray voltage. Get yourself a gfci outlet or breaker for that line. Unplug everything to the tank. Hook up ground probe. Plug one thing in at a time until you find the one that trips the breaker. Then you will know which device is the culprit

 

[vetteguy53081]

Stray voltage without a ground probe is bad. You will have to be grounded for you to feel that stray voltage.
Stray voltage with a ground probe is arguably worse, because it gives the current a place to go. Another words completes the circuit, you won’t need to be grounded to feel it, simply touch the water, and your fish feel it too
A ground probe plugged into a gfci outlet is the only way to go.
With a ground probe into a regular outlet you will need, around, the amperage that the breaker is rated for to trip. Another words 20 amps for a 20 amp breaker, etc. That’s a lot of power to get zapped with in water.
With ground probe plugged into gfci, a very slight fluctuation in ground will trip it. You might not even feel it.

Gfci will trip with stray voltage. Get yourself a gfci outlet or breaker for that line. Unplug everything to the tank. Hook up ground probe. Plug one thing in at a time until you find the one that trips the breaker. Then you will know which device is the culprit

I have mine plugged into wall directly and it stopped the voltage immediately++

 

[Brew12]

So I decided to put in a ground probe and now I can feel electrical current when I reach into the tank. When I take the probe out I can no longer feel the electricity when I put my arms back in. What should I do now? Thanks!

It does sound like your ground probe is acting like a source. The only way this should be possible is if the ground connection you are using for the ground probe is not actually connected to ground. The other possibility is that you are touching something energized that is outside the water and the ground probe is acting to complete the circuit.

If you have a voltmeter I would take a voltage from the probe (with it out of the water) to the ground of an extension cord plugged into a receptacle from another room. If the voltage is 0VAC you can try taking a resistance and it should be less than 0.2 ohms.

And as stated, GFCI's are a great idea for a tank, but I encourage using more than one so a single failed piece of equipment can't trip the GFCI and crash the tank.

 

[Brew12]

Stray voltage with a ground probe is arguably worse, because it gives the current a place to go. Another words completes the circuit, you won’t need to be grounded to feel it, simply touch the water, and your fish feel it too

I agree with much of what you say other than this. Currents are continuously flowing through our tanks. In most situations, the ground probe will act as a drain and actually reduce the total current flowing through the tank.

If you have an electrical background you can think of our tanks induced voltages as a very high impedance transformer. Under no or little load it will produce the rated voltage on the output. If you start pulling current on the secondary, you get a current spike as voltage collapses but then voltage and current flow stay very low.