Grounding Probes – The Debate

[redfishbluefish]

Grounding Probes came up in another thread and I’m going to be so bold as to open this can of worms on grounding probes. I don’t like them. The only thing they protect is you, and you’ll never know that you have a voltage leak until you see your fish dying. Not to mention that you’re expendable. Grounding probes complete the circuit to allow electricity to flow. Without the probe, no flow of electricity, unless it is finding a ground elsewhere. The tingle (or shock) you feel when you put your hand in your tank is the notice that you have a voltage leak. Find the culprit and get rid of it. Again, the grounding probe would not allow you to know you have a voltage problem. I’ve said my piece, now let the probers speak!

 

[Hawkeye]

i have not used mine since i read about your objection to it long ago. Guess I should sell it!

 

[Gonzapa]

Paul. I am with you, I think if you have a voltage leak you need to fix it. A grounding probe is just a band aid.

 

[malulu]

without a ground probe, you may not have a chance to fix it...


i guess, *someone* need to come up with a metered ground probe!!
so, you can see it was leaking juices and also not risking to get shock!
shouldn't be too hard to make??

where is hell is Olivier when we need him??!!

 

[TanksNStuff]

Paul, this is the first I've heard of this theory.

I'm no electrician but I was under the impression that the probe protects the fish too? Correct me if I'm wrong, but isn't the damage done only if there isn't a ground?

I understand what you are saying about not knowing you have a voltage leak with a probe. But without a probe there is nothing taking the voltage out of the water which I would think could cause the damage before you can realize you have a leak.

Come to think of it... the only place I could possibly have a leak would be in my sump because there is nothing electrical in my display (thanks to a great design on the vortech). Would a voltage leak even be able to travel up through the return pipe flow to do any damage in the display? I guess if the flow is a solid tube of water it's possible and the pipe would act like a conduit? Either way, it sounds like putting the probe in the sump would be the best spot because it would "fix" it before it got to the display.

I agree that we need some kind of meter present if we are using a probe though.

 

[falconut]

Not sure whether it's good or bad to have. But, I added one about a year ago and everything's been doing fine. So, I'm just leaving it there. I have mine in the sump with all the equipment.

I'd imagine if you had stray current in the sump, the whole tank wold be effected. Water is a conductor, so I imagine it would go right up to the DT.

 

[redfishbluefish]

Paul, this is the first I've heard of this theory.

I'm no electrician but I was under the impression that the probe protects the fish too? Correct me if I'm wrong, but isn't the damage done only if there isn't a ground?

I understand what you are saying about not knowing you have a voltage leak with a probe. But without a probe there is nothing taking the voltage out of the water which I would think could cause the damage before you can realize you have a leak.

Come to think of it... the only place I could possibly have a leak would be in my sump because there is nothing electrical in my display (thanks to a great design on the vortech). Would a voltage leak even be able to travel up through the return pipe flow to do any damage in the display? I guess if the flow is a solid tube of water it's possible and the pipe would act like a conduit? Either way, it sounds like putting the probe in the sump would be the best spot because it would "fix" it before it got to the display.

I agree that we need some kind of meter present if we are using a probe though.

George, it’s not a theory, it’s a fact. I’m talking the difference between voltage versus current. If you have a voltage leak….say an exposed wire….there is voltage present. Nothing happens….it’s sort of like potential energy….something could happen, but it doesn’t until it’s converted to kinetic energy. . So this voltage just “sits” there and does nothing (although this isn’t 100% true because most animals (and maybe plants, I don’t know) would be bothered by the presence of voltage (an electrostatic field).) But for the most part, the big problem with voltage is when it starts to “flow.” Now we have current. To have current in our tanks, you have to have a place for it to go. And that’s were the grounding probe becomes the cause for current. It’s the current that’s going to kill. This is also true with you putting your hand in the tank…you’re feeling the current flow though you. If you have a probe, the electricity is going to take the path of least resistance….and that’s the probe….so you’re not going to feel the tingle. In the mean time your fish are exposed to the current and voltage of the tank and you wouldn’t know anything was wrong until you start to see death.

Could you get electrocuted by sticking your hand in a tank with a voltage leak? I’m going to say yes and probably more so if you have heart problems. However, the likelihood is extremely slim. What will happen, and I’ve felt this, is a tingle you feel when you stick your hand in the tank. In all cases I was wearing shoes, which helped insult me to ground. If I were barefooted and standing in water I’m sure the tingle would have been a bit stronger. But I now knew I had a problem that needed to be immediately addressed.

I believe you’d be better off with installing GFI/CGFI in your outlets over using a grounding probe. JMTC I'll step down off the soap box now.

 

[mnat]

In all cases I was wearing shoes, which helped insult me to ground.

You should get rid of those shoes if they are insulting you so much you fall to the floor.

 

[TanksNStuff]

Pardon the semantics Paul. I didn't mean to infer that what you were talking about wasn't proven. I just couldn't think of a better term to describe what you were saying. In hind sight, theory was probably a bad choice.

Now that you explained it in more details ( I figured you or someone else might ) I understand your point much better.

Was Craig correct about the current going from sump to display? I kind of believed it to be true too but would appreciate your opinion on that topic. TIA.

 

[onefish2fish]

i thought electricity traveled to the ground? in this case the sump? there might be less of a tingle in the display and majority of it in the sump.

i guess that also depends where the electrical source is. if you drop your lights into your display, i wouldnt go feeling for a tingle.

 

[redfishbluefish]

Pardon the semantics Paul. I didn't mean to infer that what you were talking about wasn't proven. I just couldn't think of a better term to describe what you were saying. In hind sight, theory was probably a bad choice.

Now that you explained it in more details ( I figured you or someone else might ) I understand your point much better.

Was Craig correct about the current going from sump to display? I kind of believed it to be true too but would appreciate your opinion on that topic. TIA.

Saltwater is a good conductor of electricity and if there is a continuous flow of water between the DT and sump, the juice will flow up into your DT. I would speculate that the water going “down” to the sump is gurgling and may not be continuous, but the water going “up” to the DT is a continuous column of water. That would mean if you have a voltage leak in your sump, you’d feel it when you stick your hand in the DT.

You should get rid of those shoes if they are insulting you so much you fall to the floor.

Mike, have you seen the shoes I wear….they are insulting! As a mater of fact, my wife doesn’t limit the insult to my shoes. Most days I get, “You’re not wearing that, are you?”

 

[redfishbluefish]

i thought electricity traveled to the ground? in this case the sump? there might be less of a tingle in the display and majority of it in the sump.

i guess that also depends where the electrical source is. if you drop your lights into your display, i wouldnt go feeling for a tingle.

I’m talking VOLTAGE versus CURRENT.

Let me try this analogy. Voltage is like a big jar of angry bees. They are in the jar and everybody is happy (well, maybe not the bees). But nobody is getting hurt. Current is opening that jar…the bees flow and the hurt begins.

And lights falling into the tank....this is why a GFI/CGFI would be the way to go.

 

[The_Codfather]

Thanks for the heads up Paul.. I was always under the impression that grounding probes helped the fish too

 

[The_Codfather]

After some looking around I thought maybe there was a Tank voltage detector but seems no one makes one

 

[TanksNStuff]

Sounds like a job for Paul B!

 

[PaulM]

All you would need to is install a multimeter in the middle of your ground probe. Basically cut the line on the probe and attach each end to either side of the multi meter

 

[The_Codfather]

Do they come with alarms?
Add Edit: nevermind I found some that do

 

[Mbodell]

So here is what you need to factor with grounding probes. If you have one device leaking current in the tank it won't go anywhere and the fish won't notice it. If you have a second one, the electricity will flow between the two points and electrocute everything between them. If you have one device leaking and you put your hand in the tank you are now the ground. Hopefully a gfci would trip when this happened. If you have two leaking you may also become the ground for both.

A grounding probe only protects you from being the grounding point. The current will still be traveling from the leaking devices to the probe. If you had only one device leaching current and you add a grounding probe you are actually doing more harm to the livestock.

 

[malulu]

(1) let's put aside the case of when the system was down, which sump & DT are separated.

(2) in normal operation mode, all water are connected, regardless it is in the sump or display tank, IF it is grounded, no one will get shock, not the fishes, and not you. one leak, two leak makes no different, when the leak is HUGE, that is when the GFI/CGFI started to trip.

I am thinking most likely, if you just drop a hotwire to the tank for test, the GFI/CGFI will tripped BEFORE your fishes shock to death...

- it seems like the point of NOT getting a ground probe, is "i would not know i have a leak", so they rather to get tinkling then safe...
- i would prefer safe first, and if the leak is BIG enough, the GFI/CGFI will trip. (assuming you have one installed)

 

[Mbodell]

Gfci's will trip if there is a loss of current greater than 5ma. You can have a 120v bare copper line in the tank with no ground point and a gfci wouldn't trip until you added a ground. The GFCI's have to sense a current loss from what is returning back. Without the current grounding out there would be no loss.

How are you saying there is no shock between two bad connections? If there electricity is flowing between them of course there is. Your gfci might not trip because they would be on the same outlet so the power would be returning back through. It might me nominal, but it is still there.

A grounding probe keeps you from getting shocked as it is the path of least resistance. If you become the path of least resistance then you will become the grounding point and get shocked. Also electricity in salt water dissipates over the volume that it spreads. I don't know how it applies in small systems, but there is an article by Mike Holt (I think that was his name) that goes into detail with this.