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Brew12
Electrical Gru
Fantastic, I love hearing that!
Poll: Do You Use Ground Probes
- Thread starter Brew12
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anit77
Active Member
I ran the wiring for my entire basement. When I put in the aquarium I ran two more dedicated lines just for it. In total there are three circuits for the system, the two new ones and a shared. All outlets in use have GFCI's except my mixing station, which is a fourth circuit that is also shared but not used for anything other than the station, and I plan on adding a GFCI for it soon. Of the three circuits in use for the system, all have an EB8 connected to them.
I have three heaters in the sump. 2 300w Jagers on one circuit and 1 500w Finnex on another (Both the dedicated ones). The other equipment in the sump are three pumps. 2 Jebao DCP-18000's and 1 Jebao DCP-5000. I have not tested the DT or Sump for voltage yet but this thread has got me motivated to do so.
The one thing that has been bothering me is that depending one which equipment in running there is a variance in the reading my conductivity probe reads. It started out just happening with my T5's, whenever they were on there would be a 1~2 ppm drop in the reading. So I put a Ferrite block on the cord that powers them, which had no effect. Now that I've added the the two DCP-18000's I'm seeing the same thing when they are on. I'm pretty sure these instances are due to interference from the ballasts on the T5's and the controllers for the Jebao's. The lights are suspended above the tank and the only contact with the system is through an EB8, so that one has to be interference. But the pumps I'm just not 100% about.
Do you guys think adding another ground probe in addition to the Finnex heater would make any difference? And does the heater grounding through an EB8 possibly have any effect?
I have three heaters in the sump. 2 300w Jagers on one circuit and 1 500w Finnex on another (Both the dedicated ones). The other equipment in the sump are three pumps. 2 Jebao DCP-18000's and 1 Jebao DCP-5000. I have not tested the DT or Sump for voltage yet but this thread has got me motivated to do so.
The one thing that has been bothering me is that depending one which equipment in running there is a variance in the reading my conductivity probe reads. It started out just happening with my T5's, whenever they were on there would be a 1~2 ppm drop in the reading. So I put a Ferrite block on the cord that powers them, which had no effect. Now that I've added the the two DCP-18000's I'm seeing the same thing when they are on. I'm pretty sure these instances are due to interference from the ballasts on the T5's and the controllers for the Jebao's. The lights are suspended above the tank and the only contact with the system is through an EB8, so that one has to be interference. But the pumps I'm just not 100% about.
Do you guys think adding another ground probe in addition to the Finnex heater would make any difference? And does the heater grounding through an EB8 possibly have any effect?
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Brew12
Electrical Gru
T5's and DC controllers will feed harmonics back into an electrical system. This can cause some more sensitive components to read a little off. This is likely what is happening.
You can do a quick check and test the resistance from the Finnex heater jacket to its ground prong. It should be <0.2 ohms. If it is any higher than that another ground probe may help. Connecting through an EB8 should not cause an issue either. Again, a quick check of resistance from the the ground on an outlet to the ground prong on the EB8 will show if the EB8 has a problem. You can also do a complete system check with everything plugged in by taking a resistance from the heater jacket to any ground wire in your house. That would be the easiest test and wouldn't require taking anything off line. If it shows more than 0.2 to 0.4 ohms you can start splitting things out to look for the problem.
I remember testing this out back in the late 80's.
But I have better equipment now days and I check for pieces of equipment that would leak voltage such as heaters regularly. So it is not a big issue.
But I have better equipment now days and I check for pieces of equipment that would leak voltage such as heaters regularly. So it is not a big issue.
MnFish1
10K Club member
@Brew12 Could you comment on this article and the link at the bottom - some of the things they say I firstly don't understand and so would be curious on your comments:
http://angel-strike.com/aquarium/GroundingProbes.html
http://angel-strike.com/aquarium/GroundingProbes.html
Here is the introduction to the first article:
'Conventional wisdom found in magazine articles and in the bowers of world wide web chat rooms indicated that “voltage” in aquaria is one of the factors that can cause Hole in the Head and Lateral Line Erosion. We read quotes like, “Stray voltage is something that exists in every tank. Stray voltage can be eliminated with a simple ground probe available at most pet shops in the twenty dollar range. Elimination of stray voltage is a simple step in reducing the stress on your fish. Every marine tank should be grounded for your protection and that of your fish.” Is it true? Well not exactly, and as I will discuss below, the addition of a ground probe may even make matters worse!'
Here is a quote from the second:
'So now we have a system that can electrocute both the aquarist and the fish even though there is a properly installed GFI and ground probe. Were I to remove the ground probe, there would no longer be a current path affecting the fish (they are now the "birds on a wire"). The aquarist however, is still at risk if he touches the water and a ground. In reality, induced voltages and currents will be small... so small that they are probably NOT an issue for the safety of the aquarist, but with a grounding probe present, they could be unhealthy for the fish and coral (and I suspect they probably are, since sea life has little insulation to mitigate the current flow through their bodies. I can't believe that a continuous current flowing through one's body would not cause havoc with cellular ion transport, not to mention the "jamming" of sensory organs).'
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Brew12
Electrical Gru
I keep one of these handy to quickly check for faulted components. If my main GFCI trips this allows me to easily test my equipment one by one. For those not running a GFCI, it would provide an easy way to periodically check for faults.I remember testing this out back in the late 80's.
https://www.lowes.com/pd/Shock-Bust...-Single-to-Single-Yellow-GFCI-Adapter/1135923
anit77
Active Member
Thanks Brew!
One more question about the heater. When I was getting started with my Cal & Alk levels I was getting precip on the Finnex. I'm not having that problem any more. Do you think when there is a precip buildup on the heater it will increase the resistance, kinda like an insulator? Or just due to the fact that it's saturated with the water there'd be no effect.
My thinking is that just the sheer surface area of the heater and that there was a little space with no build up, that it wouldn't be a problem.
One more question about the heater. When I was getting started with my Cal & Alk levels I was getting precip on the Finnex. I'm not having that problem any more. Do you think when there is a precip buildup on the heater it will increase the resistance, kinda like an insulator? Or just due to the fact that it's saturated with the water there'd be no effect.
My thinking is that just the sheer surface area of the heater and that there was a little space with no build up, that it wouldn't be a problem.
Mick1of10
Community Member
Many, many tears ago I almost electrocuted myself and all of the fish in the tank - stupidly let a cord out of the tank without a drip line. Next had a low voltage spike from a defective under gravel filter power head (remember those?). Since then I have always run a ground probe and when they became available, GFCI outlets. I also check for stray voltage on any new stuff (I'm an engineer, so I like to tinker and add stuff that is probably not going to help anything except my sense of adventure).
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Brew12
Electrical Gru
Thank you for posting this! This is another article that someone with enough knowledge to be dangerous put together. They get much of the electrical theory correct but they miss some big picture items.
It would take longer than I have right now to dissect everything from both articles but I want to take a minute to focus on the second section you quoted.
"So now we have a system that can electrocute both the aquarist and the fish even though there is a properly installed GFI and ground probe."
You CANNOT electrocute a marine fish without taking it out of the water. Why? The water is more conductive than the fish. The majority of current will flow around a fish, not through it. If electrofishing worked in the ocean they would use it to collect hobbyist fish. The only way a person could get shocked with a GFI and ground probe properly installed is if one of them failed, which isn't what I would call properly installed.
"Were I to remove the ground probe, there would no longer be a current path affecting the fish (they are now the "birds on a wire")."
When someone uses the "birds on a wire" analogy in relation to marine fish it should throw up warning flags that they do not know what they are talking about. Again, the salt water is more conductive than they are. The fish live IN the wire, not on it. Birds live in an insulator, dry air, which is why they don't get shocked without a path to ground.
"In reality, induced voltages and currents will be small... so small that they are probably NOT an issue for the safety of the aquarist"
This is mostly correct. Odds of receiving a fatal shock from a tank is unlikely unless you have a completely failed device and are barefoot on a wet concrete floor or touch a grounded metal light fixture. A painful shock or slight tingle is more likely. The other risk is being hurt by the reaction to the shock such as from yanking your arm back or falling off a step stool.
"they could be unhealthy for the fish and coral (and I suspect they probably are, since sea life has little insulation to mitigate the current flow through their bodies."
They don't need much insulation to mitigate current flow through them since the water around them will protect them from most of the current. It would take a very large voltage (Over 15,oooV) to drive enough current through a marine fish to cause an issue. This doesn't really matter though since it would take so much current flowing around them that the water would boil before the fish was shocked. I would ask this, what is more harmful to a fish, an unmeasurable amount of current flowing through them or a failed electrical device releasing melted plastic and copper into the system? Personally, I want to know if I have a failed component ASAP so I can get it out of my tank, hence the probe with GFCI.
"I can't believe that a continuous current flowing through one's body would not cause havoc with cellular ion transport, not to mention the "jamming" of sensory organs)"
Again, fish won't have any meaningful current flowing through them. Voltage and magnetic fields can impact their sensory organs though. I haven't seen a conclusive study on it but there is reason to believe that stray voltages can cause HLLE in fish because of the sensitivity of the lateral line. If this is true, then a ground probe is the best way to remove those voltages and would make running a ground probe healthier for the fish than not having one.
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Brew12
Electrical Gru
I doubt it was a problem but I would need to do some testing to verify that. It won't take much clean surface area for it to work like a ground probe.
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Brew12
Electrical Gru
I feel like I should comment on one other problem with this article and that is the implication that induced voltages will cause large amounts of current flow through a ground probe.
It is true that if you have a faulted electrical component you can have large amounts of current flow to ground which makes a GFCI important. If it is an induced voltage, it would take a precision ammeter to even measure the current flow. There is too much impedance between the source and load to drive more than fractions of an amp. There just is no meaningful amount of power to push current.
alton
Valuable Member
I try not to step on Brews toes on his articles and I agree with him 100% on the grounding probe with GFCI protection if has been determined the grounding means at the receptacle and service is adequate.
Whether or not it is bad for fish to have a grounding probe in their tank I wrote an article for my local fish club and I had a fish store owner post this to that thread
(From Richard at CB pets)
We know from experience that certain fish may do poorly in tanks which have stray voltage. One example is an imperator angel we had in qt that was doing really well. Moved him out for sale and all he did was hide in the corner and would not eat. Moved him back to qt and he acted fine. Moved him back out and he quit eating. Hmmmm...so I checked for stray voltage on the tank and it was 16 volts. Added a grounding probe and he immediately started swimming around normally and ate when I fed him. So I took out the grounding probe and he immediately swam to the same corner and would not move. Put it back in and he was back to acting normal.
I guess some fish are more sensitive to it than others but since they sense electrical voltage it is probably a stressor to some degree for all fish.
Whether or not it is bad for fish to have a grounding probe in their tank I wrote an article for my local fish club and I had a fish store owner post this to that thread
(From Richard at CB pets)
We know from experience that certain fish may do poorly in tanks which have stray voltage. One example is an imperator angel we had in qt that was doing really well. Moved him out for sale and all he did was hide in the corner and would not eat. Moved him back to qt and he acted fine. Moved him back out and he quit eating. Hmmmm...so I checked for stray voltage on the tank and it was 16 volts. Added a grounding probe and he immediately started swimming around normally and ate when I fed him. So I took out the grounding probe and he immediately swam to the same corner and would not move. Put it back in and he was back to acting normal.
I guess some fish are more sensitive to it than others but since they sense electrical voltage it is probably a stressor to some degree for all fish.
I use a grounded titanium heather as grounding probe.
However, if someone come up with a low voltage direct current heather - the problem should be solved for the aquarist and the need for ground probes will not be there.
Today – there is a lot of low voltage equipment – the need for 110 or 240 V equipment is not there – only for heaters
I´m not so convinced as Brew12 that electrical fields not will affect saltwater fish in one or another way. The lateral line and other electrochemical organs is the same for salt as for fresh (as I know) and I think its showed that even saltwater fish can have an electrical view how the world looks like in the same way as some freshwater fishes.
Sincerely Lasse
However, if someone come up with a low voltage direct current heather - the problem should be solved for the aquarist and the need for ground probes will not be there.
Today – there is a lot of low voltage equipment – the need for 110 or 240 V equipment is not there – only for heaters
I´m not so convinced as Brew12 that electrical fields not will affect saltwater fish in one or another way. The lateral line and other electrochemical organs is the same for salt as for fresh (as I know) and I think its showed that even saltwater fish can have an electrical view how the world looks like in the same way as some freshwater fishes.
Sincerely Lasse
MnFish1
10K Club member
@Brew12 thanks for the answer (though I didn't completely understand it haha... It sounded like the article was mixing some 'reality' with some 'fantasy'. I have had a stray voltage problem one time - and it didnt seem to affect the fish - but the coral all completely closed up - which is how I found the issue with a powerhead.
If you could give a simple step by step (or a link to one) of how to do it correctly. (hook up a GFI/Ground probe), would appreciate. I currently have an extension cord with a GFI - and not sure if it would be better to have it wired into the wall). For example, if you have an apex, and a titanium heater plugged into that - does that also work as a 'grounding probe' or does the heater need to be plugged directly into the wall. (and do you still need a ground probe).
Could you also when you have time comment on the scenarios in the second article about the danger to the aquarist with 'certain' setup examples he gives (even just to say 'no thats not right').
... It sounded like the article was mixing some 'reality' with some 'fantasy'. I have had a stray voltage problem one time - and it didnt seem to affect the fish - but the coral all completely closed up - which is how I found the issue with a powerhead. If you could give a simple step by step (or a link to one) of how to do it correctly. (hook up a GFI/Ground probe), would appreciate. I currently have an extension cord with a GFI - and not sure if it would be better to have it wired into the wall). For example, if you have an apex, and a titanium heater plugged into that - does that also work as a 'grounding probe' or does the heater need to be plugged directly into the wall. (and do you still need a ground probe).
Could you also when you have time comment on the scenarios in the second article about the danger to the aquarist with 'certain' setup examples he gives (even just to say 'no thats not right').
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Brew12
Electrical Gru
I realize this is the internet and here you have me contradicting a professor emeritus of electrical engineering. Why should I be believed over him? Good question. Lets let the math show us how this works. If you aren't a math nerd, you will want to skip this.
Typical resistance of sea water 0.2 ohms per meter. The best information I could find on marine fish resistance is 200ohms for a 9" fish, worst case, and more likely to be 800 ohms or more. I will use worst case for this math since that will give us the highest current. The 200 ohms over 9" works out to 875 ohms per meter. This way we are working with the same units.
Even though Ohms Law is a DC law, it will get us close enough for what we need in AC. Ohms Law states that Voltage = Current x Resistance (V=IR). In a parallel electrical circuit current will flow in proportion to the resistance of each possible path. Starting with each path individually with a 120V source and we can plug in the numbers. In 1 meter of seawater, 120V gives us 600 amps. 1 meter of fish (yuck) at 120V gives us 0.14 amps. Hopefully this gives an understanding of the different levels of resistance and its impact.
When we put the fish and the water in parallel we know that current will flow in relationship to the conductivity of the path. For this part, I will assume we are limited to 20A by a circuit breaker. Resistances in parallel are added this way.
So, for a worst case US system we can't get more than 0.005 amps of current running through a fish by adding a ground probe. And yes, this is still a lot but the current through the fish is likely less of a problem than the heat this would put into your system. This would heat your tank as if a 2400W heater was installed.
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Brew12
Electrical Gru
I hope I didn't imply that fish aren't impacted by electrical fields! Quite the contrary, I believe that this is a problem. I just believe that this is due much more to voltage than current.
SashimiTurtle
Turtle
@Brew12, you know I have a ground probe and a GFCI on my tank.
I had close to 50V of induced voltage on my tank but no detectable current. Installed a GFCI outlet behind the stand and stuck a grounding probe in the sump. No more induced voltage and everything in the tank is plugged into that GFCI.
I had close to 50V of induced voltage on my tank but no detectable current. Installed a GFCI outlet behind the stand and stuck a grounding probe in the sump. No more induced voltage and everything in the tank is plugged into that GFCI.
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Brew12
Electrical Gru
I think you linked the same article twice, but here is the one I believe you are referring to so that people can follow if they desire.@Brew12 thanks for the answer (though I didn't completely understand it haha
If you could give a simple step by step (or a link to one) of how to do it correctly. (hook up a GFI/Ground probe), would appreciate. I currently have an extension cord with a GFI - and not sure if it would be better to have it wired into the wall). For example, if you have an apex, and a titanium heater plugged into that - does that also work as a 'grounding probe' or does the heater need to be plugged directly into the wall. (and do you still need a ground probe).
Could you also when you have time comment on the scenarios in the second article about the danger to the aquarist with 'certain' setup examples he gives (even just to say 'no thats not right').
http://angel-strike.com/aquarium/GFI&TechnicalDetails.html
There are many ways to connect these things to make it work so covering all of the options would be challenging. The most basic breakdown I can give you is that if the motor/heater is wet I would make sure it, or its powerbar, are plugged into a GFCI. Where the ground probe plugs in isn't important at all. If you and your neighbor share a common transformer from your utility you could plug it in at their house using an extension cord and it would still work. My preference is to plug them directly into the wall which minimizes any chance of it coming unplugged or having corrosion causing a resistance issue. But is it necessary? Not at all. You can even plug them into a power strip although I would only do it with a UL listed one.
I am more than happy to help anyone who has a question on how to set their systems up. Here is an example from my first system. I wired each outlet pair using a cut up extension cord so I could plug them into my Apex. This gave me 4 controllable GFCI outlets so only the faulted component would be lost.
It would have been too much work with my new system to do that so instead I put together this.
I have one powerbar from my Profilux plugged into each side. This way a fault will only take out 1/2 of my system. I made sure that my powerheads are on one side and return pump on the other so a single fault won't cause me to lose all flow.
Most of what he puts in here is correct other than thinking that any appreciable amount of current will flow through the fish. He is still hung up on his "birds on a wire" analogy.
The only one that I see worth commenting on is this one "Suppose I had a motor (like we'd find in a power head) and I supply it power from a GFI-protected source. Then I properly install a ground probe. Now lets say that I connected an electrical generator to the motor through an insulated mechanical coupling. When the motor is turned on, it turns the generator which in turn creates a voltage. I will then connect one side of the generator to ground and the other side to my aquarium water. What will happen? Current will flow through the aquarium and out the ground probe. Will the GFI detect this and trip? No, because even through its current results from the motor-driven generator's energy, the motor's lines remain balanced."
He is absolutely correct in that a GFCI will not trip in this case and that the ground probe will be carrying the current. For this reason I highly recommend that no one installs a generator into their reef tanks that is insulated from its power supply. If a fish needs to recharge their cell phone they should give it to you so you can recharge it for them and not risk the generator in the tank. Just my opinion though.
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Brew12
Electrical Gru
Glad to help. And if there is anything specific you wanted me to comment on just ask. It does amaze me that someone who gets the high level technical stuff correct misses the simple impact of the conductivity of the seawater. Especially since he mentions how conductive it is as part of his discussion!
