Using ground probes in aquariums

[Shep]

@Brew12 So I was researching a good brand to buy and came across a few people saying that it has to be plugged directly into the wall and not a power strip or surge protector, any truth to this?

 

[Cory]

@Brew12 So I was researching a good brand to buy and came across a few people saying that it has to be plugged directly into the wall and not a power strip or surge protector, any truth to this?

Only if the power strip isnt grounded. Most power strips are

 

[Brew12]

@Brew12 So I was researching a good brand to buy and came across a few people saying that it has to be plugged directly into the wall and not a power strip or surge protector, any truth to this?

I prefer to plug it into the wall but it is not required. It will work just fine plugged into a power strip.

 

[jasonrusso]

So I was researching a good brand to buy and came across a few people saying that it has to be plugged directly into the wall and not a power strip or surge protector, any truth to this?

I bought a 3 way grounded adapter like the picture. I put the ground probe in that and then the power strip in the other. This way, if the power strip has an issue or corrosion I still have a good ground.

 

[harryball69]

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.

You talked me into getting one. just ordered it...

 

[Brew12]

You talked me into getting one. just ordered it...

Fantastic!

 

[islandbreeze]

Alright I'm sold I've tried to limit stray voltage by eliminating all electronics from my 3 tanks but my sump has some 110. I do feel a micro bit of current if I have a cut on my finger, sounds funny. However, has anyone ever tried or considered a 6 foot or maybe 3 six foot grounding rods hammered deep Into the ground connected to the probe? Why do I need to ground right next to a live circuit aka plug. Is this possible? Like they do for solar rigs? I'm curious if the voltage could be tested

 

[jasonrusso]

Alright I'm sold I've tried to limit stray voltage by eliminating all electronics from my 3 tanks but my sump has some 110. I do feel a micro bit of current if I have a cut on my finger, sounds funny. However, has anyone ever tried or considered a 6 foot or maybe 3 six foot grounding rods hammered deep Into the ground connected to the probe? Why do I need to ground right next to a live circuit aka plug. Is this possible? Like they do for solar rigs? I'm curious if the voltage could be tested

Isn't the ground in your outlet connected to the grounding rod in the ground and your cold water pipe?

The purpose of the ground probe is to trip the GFI (which is more important imho). If you don't give the stray current a path to ground then it makes a connection through the water and back through the neutral.

 

[jasonrusso]

BTW, my solar panel ground is tied into my main house ground. I guess it's whatever the code is in your state.

 

[RamsReef]

Alright I'm sold I've tried to limit stray voltage by eliminating all electronics from my 3 tanks but my sump has some 110. I do feel a micro bit of current if I have a cut on my finger, sounds funny. However, has anyone ever tried or considered a 6 foot or maybe 3 six foot grounding rods hammered deep Into the ground connected to the probe? Why do I need to ground right next to a live circuit aka plug. Is this possible? Like they do for solar rigs? I'm curious if the voltage could be tested

Your grounds are tied together at your main panel box. From there you have a ground that either connects to a ground plate / rod or your copper water pipe.
At the panel your neutral bar has one jumper connected to your ground bar. Unless this is a sub panel in which case they must not be connected.

 

[Brew12]

Alright I'm sold I've tried to limit stray voltage by eliminating all electronics from my 3 tanks but my sump has some 110. I do feel a micro bit of current if I have a cut on my finger, sounds funny. However, has anyone ever tried or considered a 6 foot or maybe 3 six foot grounding rods hammered deep Into the ground connected to the probe? Why do I need to ground right next to a live circuit aka plug. Is this possible? Like they do for solar rigs? I'm curious if the voltage could be tested

As long as you have good continuity between your outlet ground and the ground rod near your breaker box you should be good. Driving one closer would only reduce voltage by miniscule amounts.

 

[Brew12]

BTW, my solar panel ground is tied into my main house ground. I guess it's whatever the code is in your state.

Yup, it varies by state and also by installation. The grounding rod has to be within a certain distance of the solar panel. If you need your solar panel on the opposite side of the house as the breaker panel it may require an additional grounding rod.

 

[islandbreeze]

Isn't the ground in your outlet connected to the grounding rod in the ground and your cold water pipe?

The purpose of the ground probe is to trip the GFI (which is more important imho). If you don't give the stray current a path to ground then it makes a connection through the water and back through the neutral.

As long as you have good continuity between your outlet ground and the ground rod near your breaker box you should be good. Driving one closer would only reduce voltage by miniscule amounts.

Ok, that makes good sense. I guess it shouldn't matter just wondering if anyone's tried it. A probe to rod in ground that is. Let's say 4 probes, 4 outlets, unless I soldered 4 together, I'm just wondering if it would still trip gfi should I believe.

 

[islandbreeze]

Even better question for the community, using a small multi meter, what setting would I select and how could I go about measuring the very small stray current in my tanks? I would be very interested in finding out

 

[islandbreeze]

Doesn't the gfi trip when it detects the large trough milliseconds before the actual bump in current? Say a pump shorts out. The ground shouldn't matter I was thinking as long as it's solid. In Other words the ground not trip the gfi so to say the actual spike or trough before is what shuts off the circuit. I'm only just looking for way to send stray voltage to ground without adding plugs to cramped outlet area. Am I beating a dead horse here.

A lawyer once told me u never get what you don't ask for so never a stupid question right?

 

[islandbreeze]

Ok one more point then I'll shut up. I really am heart set on hurricane proof system. DC all the way, got 3 huge agm batts and working on solar plan w dc controlling possibly. We are lightning capital of usa here in swfl and I lost an established 8 yr reef during Charlie, they didn't let us back on island for whole week, sad thing was I had generator but no gas (most people forget pumps at gas stations are electronic and sometimes no power = no gas)besides I had no way back on island without special permit yada yada. I was furious almost got arrested even. If I could have my system without 1plug in an account outlet it will be my moment of victory. So, am I crazy to pursue this alternate grounding idea, is it dangerous, dumb question maybe, if ground is truly required to.be routed through gfi for gfi to trip then my question is answered but if I have no gfi on complete separate DC system why couldn't I do the rod plan? Thank you for everyone's input.

 

[jasonrusso]

Ok one more point then I'll shut up. I really am heart set on hurricane proof system. DC all the way, got 3 huge agm batts and working on solar plan w dc controlling possibly. We are lightning capital of usa here in swfl and I lost an established 8 yr reef during Charlie, they didn't let us back on island for whole week, sad thing was I had generator but no gas (most people forget pumps at gas stations are electronic and sometimes no power = no gas)besides I had no way back on island without special permit yada yada. I was furious almost got arrested even. If I could have my system without 1plug in an account outlet it will be my moment of victory. So, am I crazy to pursue this alternate grounding idea, is it dangerous, dumb question maybe, if ground is truly required to.be routed through gfi for gfi to trip then my question is answered but if I have no gfi on complete separate DC system why couldn't I do the rod plan? Thank you for everyone's input.

A GFI trips when the power leaving the hot side is not equal to the power coming back into the neutral. The GFI does not monitor the ground, only the neutral. So if you have 6 amps leaving the hot side, you will have 6 amps coming back to the neutral even if you have stray current because it will use the saltwater as a conductor to make a loop.

If you have 6 amps leaving the hot side, and you have stray current (a cracked pump), you will have 5.5 amps returning to the neutral and 0.5 amps going through the ground (which isn't monitored), this will trip the GFI. Don't confuse a GFI for a circuit breaker. A circuit breaker trips when the current hits 15 amps regardless of where it goes.

I made a backup using a computer UPC and 2 car batteries. I plugged in the bare essentials. 1 return pump and a heater. I've since installed a standby generator on natural gas so my backup only has to last for 15 seconds. I have my light on the battery now because the irritating power flashes (the ones that just reset your clocks)mess with the light timer.

 

[Brew12]

Ok, that makes good sense. I guess it shouldn't matter just wondering if anyone's tried it. A probe to rod in ground that is. Let's say 4 probes, 4 outlets, unless I soldered 4 together, I'm just wondering if it would still trip gfi should I believe.

Let me answer a few of your questions.

Only one ground probe is needed, you do not need one for every outlet. A ground probe connects your sump to your houses grounding system. You do not need multiple connections as all of your house grounds are tied together.
A GFCI does not need a ground probe, or even a ground connection, to work. As Jason pointed out, a GFCI device does not care what current is, only that the current in the hot prong and neutral prong match. It doesn't monitor ground current in any manner. A ground probe will allow a GFCI to trip immediately upon an electrical fault. If you don't have a ground probe, the GFCI may not trip until a new ground path is provided, such as salt creep or a person putting their hand in the tank.

 

[Jimmyneptune]

Do you need a ground problem for every tank /compartment on your system? I have a 93 gallon cube tank with a 20 gallon tank as a refugium followed by a 20 gallon sump with a protein skimmer and return pump. So I basically have three tanks on one system. My ground probe is in the main display to protect my fish and corals.

By the way, this is a great post a lot of people have a problem or issue with their set up and it's always one of the first things I think of is the tank grounded. I think people have lost a lot of fish or corals in the past due to being on a non-grounded display or QT.
Thanks

 

[Brew12]

Do you need a ground problem for every tank /compartment on your system? I have a 93 gallon cube tank with a 20 gallon tank as a refugium followed by a 20 gallon sump with a protein skimmer and return pump. So I basically have three tanks on one system. My ground probe is in the main display to protect my fish and corals.

By the way, this is a great post a lot of people have a problem or issue with their set up and it's always one of the first things I think of is the tank grounded. I think people have lost a lot of fish or corals in the past due to being on a non-grounded display or QT.
Thanks

Glad you appreciate the post!

One ground probe is enough to protect the entire system as long as the return pump is running. I only run with one, and it is in my sump. If everything in the system is on GFCI I wouldn't bother installing more than one. If you have an equipment failure, it will trip the GFCI and protect everything. If you don't run with everything on GFCI then I would consider installing one in each connected tank that has electrical equipment for personal safety reasons.