Using Ground Probes in Aquariums

[T Carey]

I have a small quibble with what you said in your opening post. You said " Electricity always takes the lowest resistance path to ground." That suggests that it ignores the other paths.

That is somewhat misleading. Electricity takes all paths available to it. Most of the current will go through the lowest resistance path if the other paths are much higher in resistance. There will still be some current flowing through the other paths.

 

[Brew12]

I have a small quibble with what you said in your opening post. You said " Electricity always takes the lowest resistance path to ground." That suggests that it ignores the other paths.

That is somewhat misleading. Electricity takes all paths available to it. Most of the current will go through the lowest resistance path if the other paths are much higher in resistance. There will still be some current flowing through the other paths.

True, I explained why I simplified it here in post #31
https://www.reef2reef.com/threads/using-ground-probes-in-aquariums.555682/page-2#post-5710420

 

[T Carey]

True, I explained why I simplified it here in post #31
https://www.reef2reef.com/threads/using-ground-probes-in-aquariums.555682/page-2#post-5710420

Sorry. I missed that in going through the thread.

I have had a power head develop an insulation failure on the high side of the winding. That put the tank at close to line voltage but there was little current flow since there wasn't an adequate ground for the tank. I discover this working on the tank. Fortunately i was wearing rubber soled shoes so I got a good tingle and started looking for the cause.

I have an old house with the only three pronged outlets in the kitchen and bath. Rewiring is a real issue since it would require removing the siding and insulation on a chunk of one first and second story wall.

 

[Brew12]

Sorry. I missed that in going through the thread.

No worries, these comment sections can be hard to follow. I may go edit the article to correct that. When I write papers, they tend to be technical and detailed. Most people here would fall asleep reading them. I probably go too far in the other direction on R2R in trying to make them more using friendly.

I have an old house with the only three pronged outlets in the kitchen and bath. Rewiring is a real issue since it would require removing the siding and insulation on a chunk of one first and second story wall.

Its an unfortunate but real problem in older homes. A ground probe won't do you any good, but you can still use GFCI's. They won't protect your aquarium as well but they will protect you.

 

[Greg Gdowski]

No worries, these comment sections can be hard to follow. I may go edit the article to correct that. When I write papers, they tend to be technical and detailed. Most people here would fall asleep reading them. I probably go too far in the other direction on R2R in trying to make them more using friendly.


Its an unfortunate but real problem in older homes. A ground probe won't do you any good, but you can still use GFCI's. They won't protect your aquarium as well but they will protect you.

I thought it was a good article. I think this one was especially important to make user friendly.

BTW. Couldn't you hook that grounding probe to a water pipe in the house? I'm guessing that the negative is likely connected to a pipe in an older house. Is that true?

 

[Brew12]

BTW. Couldn't you hook that grounding probe to a water pipe in the house? I'm guessing that the negative is likely connected to a pipe in an older house. Is that true?

Thank you.

As long as no plumbing modifications where made to the house so that the piping is still all metal that should work. Assuming that there is a nearby pipe, anyway. And yes, the neutral (not negative, that's a DC thing) should be connected to ground via the homes plumbing.

 

[Greg Gdowski]

Thank you.

As long as no plumbing modifications where made to the house so that the piping is still all metal that should work. Assuming that there is a nearby pipe, anyway. And yes, the neutral (not negative, that's a DC thing) should be connected to ground via the homes plumbing.

Correct! My mistake....

 

[Hybrid Ken]

Here is the other argument I have seen. The ground probe should NOT be plugged into a GFI outlet. It is what the manufacture says but I have seen people say no you have to have it plugged into a GFI or you it wont work ...you turn your tank into a giant batterie....you will burn your house down....ect ect

 

[Brew12]

Here is the other argument I have seen. The ground probe should NOT be plugged into a GFI outlet. It is what the manufacture says but I have seen people say no you have to have it plugged into a GFI or you it wont work ...you turn your tank into a giant batterie....you will burn your house down....ect ect

It shouldn't matter where it is plugged in. All you need is a connection to ground which should exist in every outlet. It would even work just as well if you ran an extension cord to your neighbors house and plugged it in there.

 

[mch1984]

Thanks for the article, I do what I can to make the tank safe. Myself and my wife and kid put their hands in the tank sometime, if I get shocked ok but I hope never them. I do have a question. I use titanium heater connected to an apex, is that acting as a group probe? Or since they are connected to the apex, do I need to get a grounding prob as well and connect it into an outlet? Also, since the grounding probe is protecting us from problems what do you suggest to check to see if there are issues? Does a voltage meter still work in this case? I've used one on my tank before, so should we use one on a regular basis just make sure there isn't a hidden issue?

 

[Brew12]

I use titanium heater connected to an apex, is that acting as a group probe?

As long as it has 3 prongs it should be just fine. The Apex does not open the ground connection to turn the outlets on and off.

Also, since the grounding probe is protecting us from problems what do you suggest to check to see if there are issues? Does a voltage meter still work in this case?

I like having everything that is wet plugged into a GFCI, that way if something fails I'll know immediately.

If you don't use GFCI's the easiest way to test is with an analog voltmeter. I have one of these that I can use.

The nice thing is that they pull a little current when measuring voltage. If the voltage is induced, the meter will drop to zero VAC. If it is a fault, you will get a solid reading. When working on circuits in a facility this is my favorite way of determining if a voltage is induced. A more modern digital voltmeter doesn't pull enough current to drop down an induced voltage.
Optionally, you can use an ammeter to test for current flow. You will have to unplug your heater to check, so it won't be part of the test, but take a current reading between the tank water and ground. If it is anything above 0.1 amps on a decent meter you may have a problem.

 

[mch1984]

As long as it has 3 prongs it should be just fine. The Apex does not open the ground connection to turn the outlets on and off.


I like having everything that is wet plugged into a GFCI, that way if something fails I'll know immediately.

If you don't use GFCI's the easiest way to test is with an analog voltmeter. I have one of these that I can use.

The nice thing is that they pull a little current when measuring voltage. If the voltage is induced, the meter will drop to zero VAC. If it is a fault, you will get a solid reading. When working on circuits in a facility this is my favorite way of determining if a voltage is induced. A more modern digital voltmeter doesn't pull enough current to drop down an induced voltage.
Optionally, you can use an ammeter to test for current flow. You will have to unplug your heater to check, so it won't be part of the test, but take a current reading between the tank water and ground. If it is anything above 0.1 amps on a decent meter you may have a problem.

Thanks for the response, I use GFCI as well but wasn't sure it would still trip with the ground. I remember now you saying it still would. I think I'm covered, my dad however I'm not sure the best approach. He has one of the old houses without grounded plugs so we will have to change something up for him.

 

[Brew12]

Thanks for the response, I use GFCI as well but wasn't sure it would still trip with the ground. I remember now you saying it still would. I think I'm covered, my dad however I'm not sure the best approach. He has one of the old houses without grounded plugs so we will have to change something up for him.

Those old houses are a challenge to make safe. It's unfortunate that it can be so expensive to modernize their wiring. This is true of using any electrical device with a 3 prong plug, not just aquariums. Those ground plugs are there for a reason.
Fortunately, GFCI's still work in those older houses.

 

[mch1984]

Those old houses are a challenge to make safe. It's unfortunate that it can be so expensive to modernize their wiring. This is true of using any electrical device with a 3 prong plug, not just aquariums. Those ground plugs are there for a reason.
Fortunately, GFCI's still work in those older houses.

Yeah and lucky enough we have full access to both plugs being used for his tank. I know he as talked about changing the plugs out to GFCI, so I will be pushing him on the subject and we'll get that done.

 

[Brew12]

Yeah and lucky enough we have full access to both plugs being used for his tank. I know he as talked about changing the plugs out to GFCI, so I will be pushing him on the subject and we'll get that done.

Your GFCI receptacles should come with little stickers that say the ground plug is not used. Make sure you use them! You don't want to risk the next person who comes along thinking they are grounded receptacles when they are not.

 

[BigTeeHaz]

 

[infinite0180]

@Brew12

I just recieved my grounding probe after reading this and deciding i should get one. I take it that the end that goes in the sump can be fully submerged right? Its not like just the titainum tip can only go in the water right? Also is it ok to plug it into a power strip or should it go directly into the wall?

Thanks!

 

[Brew12]

@Brew12

I just recieved my grounding probe after reading this and deciding i should get one. I take it that the end that goes in the sump can be fully submerged right? Its not like just the titainum tip can only go in the water right? Also is it ok to plug it into a power strip or should it go directly into the wall?

Thanks!

Yup, it can be fully submerged.

Yes, it is ok to plug it into a power strip although ideally it would plug into the wall.

 

[iReefer12]

Hi @Brew12

This was all very informative. I’ve been in the hobby 7 years and never had a ground probe before but now I’m going to install one.

A question I have, I had a dedicated GFCI outlet for the tank, but it kept tripping because of the signals from the Radions on ramp up and ramp down? (I didn’t understand it that well)

So I had an electrician remove the GFCI from the outlet that all my tank equipment is plugged into.

Will a ground probe still work here and just trip the breaker if bad things were to happen?

 

[Brew12]

Hi @Brew12

This was all very informative. I’ve been in the hobby 7 years and never had a ground probe before but now I’m going to install one.

A question I have, I had a dedicated GFCI outlet for the tank, but it kept tripping because of the signals from the Radions on ramp up and ramp down? (I didn’t understand it that well)

So I had an electrician remove the GFCI from the outlet that all my tank equipment is plugged into.

Will a ground probe still work here and just trip the breaker if bad things were to happen?

No, a ground probe will not cause a non GFCI breaker to trip unless there is a very catastrophic fault.

I would recommend doing something like this to add multiple GFCI's to your system so that a single fault doesn't take out everything.
https://www.reef2reef.com/threads/diy-gfci-installation.342874/