Using ground probes in aquariums

Brew12 · Feb 12, 2020

samnaz said:
I realize this is years old now, just wondering if you ever did put together a more detailed how-to with photos of the process? You make it sound so easy (and cheap and obviously effective) but possibly above and beyond my electrical DIY skill level.

I did actually.

DIY GFCI installation

I have a reputation for having a passion for safety, especially electrical safety. I want to share how I will be implementing GFCI on my new system. First, I made a big box store run and picked up a 2 gang, new construction style electrical box. I also picked up 2 heavy duty cords, 2 gfci...

www.reef2reef.com

justusgra1998 · Mar 11, 2020

citymouse said:
Better late than never I guess...I bought a ground probe, glad I read some of this long thread, I hadn't installed it yet because I wasn't sure what the extra thing hanging off it was and I'm unsure if the plug is GFI protected...I suppose I should know this in my own home. Also...I've had a saltwater tank for about 11 years and never knew about or even considered using a ground probe, but often worried about the "what if" scenario! So thank you for this post from years ago...lol I'm going to go plug that probe in now! auto clicker

Can I plug this (see picture) into a power strip, and the probe into this portable gfi to protect the tank?

Neotetro · Apr 2, 2020

I recently began measuring the volts of my tank and using a probe after little shocks on cuts I had when in the tank. While using the probe, there is 0 AC but 120 DC? Why would this be? Is this dangerous? I certainly don't feel anything at this point.

Brew12 · Apr 2, 2020

Neotetro said:
I recently began measuring the volts of my tank and using a probe after little shocks on cuts I had when in the tank. While using the probe, there is 0 AC but 120 DC? Why would this be? Is this dangerous? I certainly don't feel anything at this point.

That definitely doesn't sound right. You shouldn't be able to get a DC voltage that high in your tank.

Neotetro · Apr 2, 2020

Am I reading this right? mV? AC is a hard 0, no shocks

Neotetro · Apr 2, 2020

Neotetro said:
Am I reading this right? mV? AC is a hard 0, no shocks

I changed it to to measure as volts.... it's now near 0

Brew12 · Apr 2, 2020

Neotetro said:
Am I reading this right? mV? AC is a hard 0, no shocks

mV is millivolts, so that would be 0.2V which is likely not within the accuracy of the meter.

Lonelyreef · Apr 24, 2020

would using a power strip with a built GFci work with a grounding probe or should it be at the wall

Brew12 · Apr 24, 2020

Lonelyreef said:
would using a power strip with a built GFci work with a grounding probe or should it be at the wall

You should be fine with the built in GFCi.

jcfons · Apr 30, 2020

So, after going through the shock of being the circuit completion, and the sudden loss of $1000’s of fish and corals in less than 24 hours, a ground probe is a must! Excellent write up!

Brew12 · Apr 30, 2020

jcfons said:
So, after going through the shock of being the circuit completion, and the sudden loss of $1000’s of fish and corals in less than 24 hours, a ground probe is a must! Excellent write up!

I'm glad you liked the write up, but I am so sorry you had to go through that! Just glad you are still around to post!

sixline · May 17, 2020

I need to install one soon.

I've actually been unplugging my tank every time I need to stick my hands in the water, which is rarely.

How do ground probes work in conjunction with GFC outlets? Do they achieve the same purpose? Can a ground probe be plugged into a GF outlet and does it make sense to do so?

I am catching up on this 26 page thread. Apologies if these questions have already been addressed.

Brew12 · May 17, 2020

sixline said:
How do ground probes work in conjunction with GFC outlets? Do they achieve the same purpose? Can a ground probe be plugged into a GF outlet and does it make sense to do so?

Ground probes and GFCi's have 2 separate functions that compliment each other. I'll use the example of a situation where a cord starts pulling out of a pump and exposes the copper to the saltwater. Without a ground probe or a GFCI, the pump will energize the water and leach copper into the system as corrosion is accelerated by the electric current. You could potentially get a dangerous shock if you stick your hand in the tank. If you run only a GFCI, the pump will energize the water until you put your hand in the system and create a path to ground, which will trip the GFCI. If you run only a ground probe, current will flow through the ground probe until the main circuit breaker trips or the ground probe wiring melts. If you run a ground probe and GFCI, as soon as the cord starts pulling out, the ground probe will allow current to flow, tripping the GFCI immediately.

Ground probes can be plugged into any grounded outlet, it doesn't need to be in the GFCI.

HighChiefKC · Jul 7, 2020

Just came across this thread. This might be a dumb question, but where do I buy a grounding probe? I figured it was something BRS would have. But didn’t see it

robbyg · Jul 7, 2020

HighChiefKC said:
Just came across this thread. This might be a dumb question, but where do I buy a grounding probe? I figured it was something BRS would have. But didn’t see it

Here you go. This looks like the one I installed 15 years ago and it still in good shape.
Comes in single or double pack.

vetteguy53081 · Jul 7, 2020

Amazon, ebay, Marine depot, aquarium specialties and Aqua cave

spllbnd2 · Jul 7, 2020

Those probes are a nice to have item for the tank. But we should all know how to find the root cause of stray voltages in our tanks and fix the problem.

How to Test for Stray Voltage

Purchase or borrow a voltage meter. They can generally be found for less than $20 at most automotive parts or hardware stores. Try Harbor Freight. I personally use Fluke equipment for testing both at home and on the job.
Turn the selector to "120 AC Voltage."
Insert the tip of the black probe into the third or "grounding" hole in an electrical outlet.
Insert the metal tip of the red probe into the aquarium water.
Watch the meter needle for any movement. Any needle movement indicates a voltage leak in your system. Digital meters will show a number reading.

How to Identify the Voltage Leak Source

One at a time, disconnect each electrical appliance (heaters, pumps, lights, chiller, filter) associated with your aquarium, retesting for voltage as described above after each unit is disconnected.
Heaters and water pumps (powerheads) are the most frequent cause of voltage leaks. These devices have 120 volts of electricity feeding into them, which is enough to do a lot of damage in a saltwater aquarium.
When the damaged electrical device is found, disconnect it from the electrical circuit carefully. Keep your hands out of the aquarium and don't handle equipment with wet hands in order to avoid electrical shock.

How to Solve the Voltage Leak