Using Ground Probes in Aquariums

[Brew12]

Know if i’m holding positive wire it doesn’t hurt until I touch neutral or ground, lol

This is a great way to describe what happens in our tank. If you are holding a positive wire you can't tell if there is current flowing through it or not. As soon as you touch neutral or ground you will feel it even if there had previously been no current through the wire.

In one of my tanks that I was feeling electric. Added a ground probe, tripped gfci. Tried it in another gfci, same thing. Plugged things in one by one til I found it was external return pump. Plugged it into regular outlet and it’s fine, except for the slight electric shock in the water. Guess it will stay that way until I get around to changing that pump. Am I missing something?

Where you plug the ground probe in doesn't matter. You could plug it into your neighbors house using an extension cord and it would function the exact same way.
I would change out that external pump ASAP. It could be leaching copper or other contaminants while it is running.

 

[Hybrid Ken]

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

That's incorrect from every thing I have ever read in researching proper grounding of a salt water tank. The water and probe are more conductive then the fish and you thus you only hear of electric eels in fresh water as in fresh water the fish are as conductive as the water (unless you are standing in a puddle) and the stray voltage will go to the probe/ground. It is basically giving the voltage a "path of least resistance" with out a probe you become that possible path under the right situation. As for the GFI or not is up for debate but every manufacture says to plug the probe into the wall outlet and not a power strip or extension cord.

 

[Hybrid Ken]

What do you mean by “secondary”?
Yeah, way above my pay grade...
Know if i’m holding positive wire it doesn’t hurt until I touch neutral or ground, lol

In one of my tanks that I was feeling electric. Added a ground probe, tripped gfci. Tried it in another gfci, same thing. Plugged things in one by one til I found it was external return pump. Plugged it into regular outlet and it’s fine, except for the slight electric shock in the water. Guess it will stay that way until I get around to changing that pump. Am I missing something?

Agree with more than one gfci suggestion, and good call on checking ground probe source to op

The problem with plugging a ground probe in is knowing that it is actually a functioning ground. some power strips will loose ground when they trip or blow and if the device causing the issue is on a different power strip the problem voltage is still there and the probe is now useless. I paid a few extra bucks to make sure I have a good ground on one outlet at the tank and that's where I put my probe. Older houses are notorious for having a outlet that looks like it has a ground but actually has no ground at all.

 

[BeejReef]

@Brew12

So, I'm not looking to cheap out on a $12 ground probe, but the best ground in all of my house runs directly behind my tank. Two iron hot water pipes that carry hot water from the radiators to the boiler in the basement. Can I just run an 18" length of stainless wire from the sump to these pipes?

 

[Brew12]

@Brew12

So, I'm not looking to cheap out on a $12 ground probe, but the best ground in all of my house runs directly behind my tank. Two iron hot water pipes that carry hot water from the radiators to the boiler in the basement. Can I just run an 18" length of stainless wire from the sump to these pipes?

You can, but I wouldn't. Or at least if you do, check the wire for corrosion regularly. Very few grades of stainless steel will hold up to continuous exposure to salt water. You may end up with excessive chromium in your system if you aren't careful.

 

[Dierks]

@Brew12

So, I'm not looking to cheap out on a $12 ground probe, but the best ground in all of my house runs directly behind my tank. Two iron hot water pipes that carry hot water from the radiators to the boiler in the basement. Can I just run an 18" length of stainless wire from the sump to these pipes?

Yes you can do that but you are going to want to get a Titanium end to place in the Sump. You dont want any metals getting into your water.

 

[BeejReef]

Ty both @Dierks and @Brew12


I'll look into a titanium piece for the sump. I just have more confidence in this particular ground than the house wiring, gfci or not.

 

[Rimsky]

I'm reviving this interesting thread.

Nowadays, most AC pumps, waves, etc. have been replaced with DC equipment. Assuming that ALL your equipment in contact with water is DC, the grounding probe is really needed? Let's say you have:
1. Everything connected to GFCI outlets
2. All the equipment in contact with water is DC (return pump, skimmer pump, wave makers, ATO pump, etc.).
3. No grounding probes

My house is very old so I always doubt that my ground is 100% proper. So I would rather eliminate my grounding probes connected to doubtful ground than have them in this scenario.

Your thoughts?

 

[vetteguy53081]

I'm reviving this interesting thread.

Nowadays, most AC pumps, waves, etc. have been replaced with DC equipment. Assuming that ALL your equipment in contact with water is DC, the grounding probe is really needed? Let's say you have:
1. Everything connected to GFCI outlets
2. All the equipment in contact with water is DC (return pump, skimmer pump, wave makers, ATO pump, etc.).
3. No grounding probes

My house is very old so I always doubt that my ground is 100% proper. So I would rather eliminate my grounding probes connected to doubtful ground than have them in this scenario.

Your thoughts?

While i agree with your thoughts, I still use ground probes for the purpose of " What if"

 

[Rimsky]

While i agree with your thoughts, I still use ground probes for the purpose of " What if"

Thanks for your reply.
But in this "low risk scenario" (full DC equipment and GFCI), What If an AC device in the house hot or neutral touches ground and that is what ends up affecting your tank via grounding probes? Sorry for my ignorance, I don't know if that is even possible, but I imagine that being even a higher risk than having the grounding probes in the first place -- in this scenario.

 

[acrocapital]

Seawitch submitted a new Article:

Using Ground Probes in Aquariums

Note from the Editor: Some time ago, our resident electrical guru, @Brew12, wrote a good article on the forum at the beginning of a discussion thread about using ground probes for your aquarium. As soon as I saw the article, I recognized that this deserved top billing. So, here, below, is our resident electrical guru's suggestions on ground probes in his own words. Hint: You need one.

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Photo by rawpixel.com from Pexels

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.

Does your aquarium system control panel look like this? Then get a ground probe.

This is a royalty-free image from Pixabay.

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Author Profile: @Brew 12

Steven Frick has spent much more time under the ocean than keeping a small piece of it. He got his start in the electrical field in the US Navy Nuclear Power program as an electrician's mate. After 5 years of service on the submarine USS Henry M Jackson he finished his final 3+ years of service teaching electrical theory at the Knolls Atomic Power Laboratory.

Currently, he runs the projects and maintenance for the power distribution system of one of largest electrical consuming heavy industrial companies in the Southeastern United States. He wrote his sites' electrical safety policies and routinely acts as a consultant to other industrial facilities looking to improve their electrical safety programs. As someone who loves to both learn and teach, he has focused his attention on his newest hobby, reefing.

Well said! Couldn't agree more.

 

[rtparty]

Have never run one and never will. I also won’t run a tank on a GFCI for any reason. They false trip far too often and you come home to a totally dead tank

 

[Rimsky]

Have never run one and never will. I also won’t run a tank on a GFCI for any reason. They false trip far too often and you come home to a totally dead tank

I agree, but if there is an accident and a human life is lost, that is worth the risk of having the GFCI false tripping. To mitigate that risk of false tripping, I have the Apex. If the return pump is off, there is a notification. If Apex is off, Fusion notifies.

Another option is putting everything except the return pump on GFCI and making sure that the power cable of the return pump is not touching the floor, etc.

Even if all equipment is DC, I imagine the GFCI protecting for the water spill scenario in which me or a family member walks bare footed and there is an AC cable (to a DC brick) getting wet.

 

[rtparty]

I agree, but if there is an accident and a human life is lost, that is worth the risk of having the GFCI false tripping. To mitigate that risk of false tripping, I have the Apex. If the return pump is off, there is a notification. If Apex is off, Fusion notifies.

Another option is putting everything except the return pump on GFCI and making sure that the power cable of the return pump is not touching the floor, etc.

Even if all equipment is DC, I imagine the GFCI protecting for the water spill scenario in which me or a family member walks bare footed and there is an AC cable (to a DC brick) getting wet.

Nope. No one is dying from my tank and how it’s setup. If only the return pump ran on my tank, everything would die anyway from the cold basement.

 

[SaracensRugby]

I had a 60 cube about 5-6 years ago. Read about grounding probes, so put one in the sump. Immediately, IMMEDIATELY my clowns started jerking around erratically when I plugged it in. I unplugged it, back to normal for the clowns. I'm not an electrician by trade, but that was enough for me not to use one again. Maybe I used it wrong (don't think I did), but that was enough evidence for me.

 

[Hooz]

I'm reviving this interesting thread.

Nowadays, most AC pumps, waves, etc. have been replaced with DC equipment. Assuming that ALL your equipment in contact with water is DC, the grounding probe is really needed? Let's say you have:
1. Everything connected to GFCI outlets
2. All the equipment in contact with water is DC (return pump, skimmer pump, wave makers, ATO pump, etc.).
3. No grounding probes

My house is very old so I always doubt that my ground is 100% proper. So I would rather eliminate my grounding probes connected to doubtful ground than have them in this scenario.

Your thoughts?

One of the biggest culprits of stray voltage in a tank is a faulty heater. I don't know of anyone making a DC heater yet, do you?

 

[Reefer Matt]

All five of my tanks have a gfci and ground probe. No false trips in over six years. If yours trips, find and replace the faulty equipment. You MUST use a gfci if you use a ground probe. A ground probe completes the circuit in the case of faulty equipment. Without a gfci, and a probe installed, the tank becomes energized during a short. Without using either, you risk a fire and electric shock if a short occurs. Forget “stray voltage”, use common sense when mixing electricity and water. You, your family, and your home are worth more than a reef tank.

 

[nereefpat]

You MUST use a gfci if you use a ground probe.

I agree. Unfortunately, I think there are lots of reefers that have ground probes in the tank but no GFCI.