Using ground probes in aquariums

[ingchr1]

...Like I mentioned earlier this probe is redundant. You already have sufficient grounding via any equipment used in or around your tank.
GFCI’s do work well and they are all that’s needed for safety.

Is it?

None of the AC equipment (return pumps and heaters) in my tank has a ground.

 

[jasonrusso]

Is it?

None of the AC equipment (return pumps and heaters) in my tank has a ground.

I don't know where this guy is coming from. How would a plastic pump (non conductive housing) that has a crack transfer current if there is no ground to transfer to?

 

[Cygnus]

Is it?

None of the AC equipment (return pumps and heaters) in my tank has a ground.

They are called double insulated. Same with electric hand tools with only two wires. There is no ground because they have been designed this way and have UL certification.
I looked at my equipment and I don't have any three wire equipment either. So this is a good point.

I don't know where this guy is coming from. How would a plastic pump (non conductive housing) that has a crack transfer current if there is no ground to transfer to?

It does not transfer current unless there is a fault. In this case your circuit breaker should trip.
Has anyone actually done any research on grounding probes?
There are as many that think like I do as those who think its a good idea.
GFCI trips at 4-6 ma. This is protection.

 

[ReeferSamster]

Heres one thing i noticed many years ago and this happened on more than one occasion with more than one type of fish:

Sometimes you get those fish that 'pace' along the glass of the aquarium even though other fish dont seem bothered. Maybe their personalities are more sensitive...

When I installed a ground probe. They stopped pacing and exhibited more natural behaviour. (pecking at liverock for critters, having fun fighting the flow of my gyres.) They seemed more 'content' in their world instead of trying to get out of it.

This is purely anecdotal, so take it with a grain of salt but there have been enough occasions, and experimentation for me in my humble experiences to have a belief in ground probes.

 

[markwayts]

I've had one in every tank after I got knocked on my rear due to a faulty heater

Same for me execpt it was 3 different times, 1 heater and 2 different powerheads.

 

[markwayts]

Why is it that some people refuse to put a grounding probe in their aquarium? I've seen many arguments against using them, some of which are based on what I believe to be bad information. I want to make the case for why every aquarium should have a grounding probe installed.
We have these beautiful aquariums full of salt water into which we place electrically operated equipment. Everyone has heard the phrase "Water and electricity don't mix" and it is especially true of salt water. Yet this doesn't have to be dangerous and a ground probe is key to making this safe.

An electrical shock occurs when current flows through a person. There are three main factors that impact the severity of the shock. The amount of current flowing through the person, the length of time they are being shocked, and the path the current takes through the body. For a shock to occur a person must be touching an energized conductor and a source to ground. The glass and acrylic most aquariums are made from are excellent insulators. If a pump or heater develops a fault in the salt water, it will raise all of the water in the aquarium to the same voltage as is available at the fault, typically close to 115V. If you are touching the metal housing of a light fixture or standing on wet concrete and touch the water, you become the best path for the current to take to get to ground. These shocks are most likely to take the most dangerous path, which is through our heart. It will go into the hand, through the heart, and either out the opposite hand or down through our legs. This is one way the ground probe keeps us safe. Electricity always takes the lowest resistance path to ground. The human body does have some resistance so a properly maintained ground plug will always offer a lower resistance path to ground.

I would also make the argument that the use of a ground plug is important to the health of our marine fish, but not because of a risk of electrical shock. Scientists use electro-fishing techniques to collect or count fish populations by shocking fish. Electric eels hunt prey by shocking them with electricity. So why do I say marine fish are not at risk for being shocked? They live in salt water. Electric eels are a fresh water species and electro-fishing only works fresh water. In a fresh water environment the fish is more conductive than the water just like people are more conductive than air. You cannot shock a marine fish while it is in salt water since the water is more conductive than the fish. This doesn't mean that marine fish aren't affected by electricity.

It is a generalization to say that all of the salt water is at the same voltage in our aquariums. In reality, small differences in potential can exist within the water. Eddy currents of water will cause a difference in voltage. There will be a difference in potential caused by any air bubbles that may touch a fish. While these may not cause shocks, it can cause a serious irritation across the surface of the fish. I would also point out that you do not need to have an electrical fault to have a harmful voltage in your aquarium. Any energized cord either running in the water or along the outside of the tank will create a voltage in the tank using a process called induction. This is why many people see a voltage in their aquariums without having a GFCI breaker trip. A ground probe will prevent any voltage from building up in the aquarium water, protecting our fish from these small voltage differences.

Grounding probes also protect our tank from another problem that is much harder to see and correct. If you have an electrical fault in your tank, there is a high probability that you have exposed copper in your system. This copper will corrode in salt water and the corrosion is accelerated when impacted by electricity. Even if you use a GFCI, the circuit will not trip on a fault until you have a source to ground. A ground probe will immediately provide that path to ground. If you do not have a ground probe installed, you could be leaching copper into your system for days or longer until a path to ground from your water is established.

The one argument against using ground probes I cannot counter is that it could provide a heat source during an electrical fault. If you have an electrical fault in a very narrow resistance range, and do not use GFCI protection, it can act like a heater. I know I wouldn't risk the safety of my family and friends in an effort to avoid this one scenario. I hope after reading this you won't either.

Most of your electric pumps and heaters and other stuff is in your sump. A ground probe in your sump will protect you and your tank from dangerous shock. It's only a matter of time until something breaks and leaks voltage into your tank. I've had a heater and 2 different power heads short out and shock me in 13 years of owning a reef tank.

 

[alton]

Its been a while since I have posted and there are 31 pages so;
Before you use a grounding probe make sure sure service grounding at the panel and receptacle is adequate. If not it will use your tank as a grounding means. One friend who lived in the hill country in rock had a very poor grounding means. Result 2 volts in sump but milli-amps were through the roof and the shock was really bad. Pulled out the probe, shock went away. Also fixed his grounding problem, but he still didn't use the probe. Second friend, had a GFCI, grounding probe and heaters where shocking him and GFCI didn't trip. He had an older home and when the person before him replaced the receptacle with a grounded GFCI there was no grounding wire, and they didn't place the little sticker on the receptacle that stated this. So grounding probe was worthless. GFCI receptacles and breakers are made to save your life, not stop you from getting shocked. 1 Milli-amp is a tingle, 3 to 4 milli-amp is a pretty good shock. Just remember without a grounding means a GFCI will not trip. You really do not want to be that grounding path.

 

[jmichaelh7]

I don’t have a gfci on my outlet but I purchased a ground probe.

Can I install this and be safe ?

 

[capted]

I would absolutely install a gfci outlet first. If there was a short in the tank the ground probe will complete the circuit and may even burn your wiring if the circuit breaker does not "pop".

 

[Paul B]

I don’t have a gfci on my outlet but I purchased a ground probe.

Can I install this and be safe ?

Safer than without it.

 

[jmichaelh7]

I would absolutely install a gfci outlet first. If there was a short in the tank the ground probe will complete the circuit and may even burn your wiring if the circuit breaker does not "pop".

Not possible the tank is sitting in front of the outlet and sump is blocking it

 

[Bebow]

Not possible the tank is sitting in front of the outlet and sump is blocking it

I had the same problem with my FW 90. I had enough space to get a plug-in GFCI. They do the job and are easier to reset.

 

[lonepalm99]

Great wrote up. Thanks for showcasing this information

 

[bluerider098]

I use a ground probe GFCI combination. It does not matter where you plug the ground probe in. You could plug it into your neighbors house and it would work the exact same way.

What outlet will trip, your neighbors or the one with the short?

 

[KStatefan]

What outlet will trip, your neighbors or the one with the short?

The GFCI where the imbalance is.

 

[drtechno]

I know that this discussion is about grounding probes, but with so many posts about GFCI, I would like to put in my 2 cents - install a GFCI breaker instead of a GFCI receptacle. The breakers are far more reliable and (from my experience) have no nuisance trips.

I have gone through numerous receptacles due to either outright failures (trip and won't reset) or nuisances tripping in my house (tank is not running yet). I have yet to see my GFCI breakers nuisance trip or fail. I also split the difference in my setup, two returns pumps on different circuits, one protected by breaker, one by receptacle. Sorry for tangent

 

[james2369]

Fantastic. Just knowing that one or two people are buying grounding plugs because of my post makes the time I put into this worth while!

Well here it is 2022 and I'm now buying one because of the post
Thanks

 

[BeanAnimal]

I skimmed the thread - wow is there a LOT of bad information here.

Fist of all - electricity DOES NOT take the path of LEAST RESISTANCE. It takes ALL PATHS in proportion to their resistance.

Ground probes can cause as many problems as they resolve, both from a safety standpoint and tank health standpoint when looked at from a micro current to macro current perspective.

I would NEVER run a ground probe without EVERY piece of equipment connected to the aquarium being grounded.

Let me give you a common scenario:

You have A metal halide reflector in the hood. The reflector has become energized by a bad ballast, floating neutral, or for that matter has induced current due to poor design. You stick your hand in the tank and your bare neck touches the reflector while doing so.

NO GFCI and NO PROBE - The tank IS NOT grounded. You likely DO NOT get shocked. There is no path for current to flow. Standing on concrete with bare feet? You DO get shocked. So safe in some fault conditions and not others.

GFCI Alone - The GFCI breaker may or may not have tripped, depending on the grounding status of the reflector itself. If it has not tripped when you contact the reflector and water (with shoes on) nothing changes. Bare Feet? The GFCI trips and protects you because the current leaks through you to the floor (not the tank). So still safe for the tank, and now safe for you.

GROUND PROBE ALONE (NO GFCI) - as soon as you touch the reflector and the water, YOU ARE NOW PART OF THE CIRCUIT. You get shocked or electrocuted as the current passes through your heart on the way to the water and ground probe. This is FAR MORE dangerous than the ungrounded tank!!!!

GFCI with GROUND Probe - same as above, but if the breaker has not already tripped due to the ground fault in the ballast, it will as soon as you touch the reflector and water, as the current will flow through the reflector, to you to the tank and then to the probe. Outcome - safe for you and for fish in any reasonable scenario... OR IS IT?


We can go through the same exercises with faulting equipment IN the water (a frayed powerhead cord for example) and the outcome is similar. The only difference... Without the GFCI the ground probe actually allow sustained current flow in the aquarium. If there was a GFCI there, you would no that there is a problem (it would keep tripping).

Please do not use a ground probe unless all of the equipment in, on and near your aquarium are protected by GFCI!!!!

I don't wish to get into the micro current and fish/coral health debate and how probe behaves in these scenarios, let's just say that they can cause more current to flow being present, than if they were skipped totally. (Back to the first statement about where electricity flows).

 

[vetteguy53081]

I skimmed the thread - wow is there a LOT of bad information here.

Fist of all - electricity DOES NOT take the path of LEAST RESISTANCE. It takes ALL PATHS in proportion to their resistance.

Ground probes can cause as many problems as they resolve, both from a safety standpoint and tank health standpoint when looked at from a micro current to macro current perspective.

I would NEVER run a ground probe without EVERY piece of equipment connected to the aquarium being grounded.

Let me give you a common scenario:

You have A metal halide reflector in the hood. The reflector has become energized by a bad ballast, floating neutral, or for that matter has induced current due to poor design. You stick your hand in the tank and your bare neck touches the reflector while doing so.

NO GFCI and NO PROBE - The tank IS NOT grounded. You likely DO NOT get shocked. There is no path for current to flow. Standing on concrete with bare feet? You DO get shocked. So safe in some fault conditions and not others.

GFCI Alone - The GFCI breaker may or may not have tripped, depending on the grounding status of the reflector itself. If it has not tripped when you contact the reflector and water (with shoes on) nothing changes. Bare Feet? The GFCI trips and protects you because the current leaks through you to the floor (not the tank). So still safe for the tank, and now safe for you.

GROUND PROBE ALONE (NO GFCI) - as soon as you touch the reflector and the water, YOU ARE NOW PART OF THE CIRCUIT. You get shocked or electrocuted as the current passes through your heart on the way to the water and ground probe. This is FAR MORE dangerous than the ungrounded tank!!!!

GFCI with GROUND Probe - same as above, but if the breaker has not already tripped due to the ground fault in the ballast, it will as soon as you touch the reflector and water, as the current will flow through the reflector, to you to the tank and then to the probe. Outcome - safe for you and for fish in any reasonable scenario... OR IS IT?


We can go through the same exercises with faulting equipment IN the water (a frayed powerhead cord for example) and the outcome is similar. The only difference... Without the GFCI the ground probe actually allow sustained current flow in the aquarium. If there was a GFCI there, you would no that there is a problem (it would keep tripping).

Please do not use a ground probe unless all of the equipment in, on and near your aquarium are protected by GFCI!!!!

I don't wish to get into the micro current and fish/coral health debate and how probe behaves in these scenarios, let's just say that they can cause more current to flow being present, than if they were skipped totally. (Back to the first statement about where electricity flows).

Agree. . . . probes are great but an alternative and not a solution until the leaking source of energy is located.

 

[BeanAnimal]

Agree. . . . probes are great but an alternative and not a solution until the leaking source of energy is located.

Yep - They can also cause fires in some instances. All in - they create far more danger than they alleviate if they are not used in conjunction with full GFCI protection. There are opinions, and simple hard science. Electricity in this context (again ignoring stray voltage/current and coral/fish health) is hard science.