Using ground probes in aquariums

[powers2001]

I like these, off Amazon. If you can’t find what you need at the big box stores. I just ordered another one (I think my 5th) today, to be here tomorrow.

@JumboShrimp these aren’t necessarily necessary if your circuits are on circuit breakers. The breakers in your box do the same thing.

 

[kcschwabe]

Ok so now I’m a lil bit worried can some one please tell me how would I know or find out that I had a voltage leak on a piece of equipment without pulling it out and testing it Ps ( no controller )

 

[srobertb]

Ok so now I’m a lil bit worried can some one please tell me how would I know or find out that I had a voltage leak on a piece of equipment without pulling it out and testing it Ps ( no controller )

Well..I stuck my hand in my saltwater mixing tank last week and learned very quickly that my cheap ace Amazon special power head was leaking electricity. So there’s that…

 

[JumboShrimp]

Thanks, @powers2001. I guess like you say, it at least gives me a convenience-factor right behind the tank.

 

[srobertb]

I've used one for as long as I can remember.

Can you just plug it into any outlet? How about an outlet on a surge protector or Apex? Forgive my naivety is this is stupid.

 

[Brew12]

@jmichaelh7 you should have circuit breakers on every outlet in your house or it probably won’t comply with the building codes set by your local municipality. Those breakers are in your breaker box and are the same things as the GFCI at the wall outlet. The only reason an electrician installs one of those GFCIs as a wall outlet is if the owner wants to be able to flip the switch back on at the wall outlet instead of going all the way to the breaker box to switch back on or if the wall outlet you’re going to use doesn’t have a breaker in the box.

This is not correct. A traditional circuit breaker trips when a circuit pulls too much load, typically more than 15amps. The more load, the faster it trips.
A GFCI device does not care about total load. You could pull 100A in a 15A circuit and a GFCI will not trip. A GFCI trips there is a difference of in current of more than 5mA between the hot and neutral prongs of an outlet.
You can have GFCI circuit breakers but they aren't nearly as common.

 

[capted]

This is not correct. A traditional circuit breaker trips when a circuit pulls too much load, typically more than 15amps. The more load, the faster it trips.
A GFCI device does not care about total load. You could pull 100A in a 15A circuit and a GFCI will not trip. A GFCI trips there is a difference of in current of more than 5mA between the hot and neutral prongs of an outlet.
You can have GFCI circuit breakers but they aren't nearly as common.

Great explanation! I always thought they looked at voltage not amps. I assume they will work in an ungrounded body of water like a pond with a rubber liner. I have to ask though why my gfci popped but not the breaker when I cut a wire with a shovel? I assume it sensed a current difference by maybe the neutral getting cut.

 

[Brew12]

Great explanation! I always thought they looked at voltage not amps. I assume they will work in an ungrounded body of water like a pond with a rubber liner. I have to ask though why my gfci popped but not the breaker when I cut a wire with a shovel? I assume it sensed a current difference by maybe the neutral getting cut.

Good questions.

As a general concept, voltage based protections are very unusual in residential and even industrial systems. I do use them at work, but for very specific functions (I manage a 500kV substation among other responsibilities)

A GFCI will typically not work in a pond with a rubber liner just like it won't work in an aquarium because glass is an insulator. The current needs to have a path to ground which is blocked by the rubber and glass. This is where a ground probe comes in for salt water aquariums. It provides the path to ground. Pure water is also a very good insulator. A ground probe would do very little in a pond or fresh water system because the fresh water insulates the failed electrical device from the ground probe. The salt in saltwater makes it conductive to electricity so the water completes the circuit between the ground probe and failed device.

As for cutting the wire, there is a very good chance that it became a race. The circuit breaker overcurrent protection is designed with a slight time delay. The GFCI is designed to trip as fast as possible so it should have tripped first. Not because it went from hot to neutral, but because it went from hot, through the shovel, to ground. To turn a light on or off you normally only open one wire, preferably the hot, but that should never trip the gfci.

 

[jmichaelh7]

Well I ordered the ground , and the GFCI adapter on Amazon. From here on out if I stick my hand in the water , I’m turning everything off on apex and then the GFCI shall also be a second preventive measure

 

[JumboShrimp]

(I love what you have posted, @Brew12 “He who asks a question is a fool for five minutes; he who does not ask a question remains a fool forever.” - Chinese proverb.)

... And so to boil it down for us 'five-minute-fools'... If I just plain-old don't want to get z-a-p-p-e-d, should I have a grounding probe in my tank, a GFCI, both, or dare I ask: A grounding probe plugged INTO a GFCI? Thanks in advance.

 

[capted]

Good questions.

As a general concept, voltage based protections are very unusual in residential and even industrial systems. I do use them at work, but for very specific functions (I manage a 500kV substation among other responsibilities)

A GFCI will typically not work in a pond with a rubber liner just like it won't work in an aquarium because glass is an insulator. The current needs to have a path to ground which is blocked by the rubber and glass. This is where a ground probe comes in for salt water aquariums. It provides the path to ground. Pure water is also a very good insulator. A ground probe would do very little in a pond or fresh water system because the fresh water insulates the failed electrical device from the ground probe. The salt in saltwater makes it conductive to electricity so the water completes the circuit between the ground probe and failed device.

As for cutting the wire, there is a very good chance that it became a race. The circuit breaker overcurrent protection is designed with a slight time delay. The GFCI is designed to trip as fast as possible so it should have tripped first. Not because it went from hot to neutral, but because it went from hot, through the shovel, to ground. To turn a light on or off you normally only open one wire, preferably the hot, but that should never trip the gfci.

Good point about saltwater being more conductive. Now you have me thinking about my pond. If the pump wire somehow leaked voltage I wonder if it would shock me then pop the gfci as now I am the ground path?

 

[jasonrusso]

@jmichaelh7 you should have circuit breakers on every outlet in your house or it probably won’t comply with the building codes set by your local municipality. Those breakers are in your breaker box and are the same things as the GFCI at the wall outlet. The only reason an electrician installs one of those GFCIs as a wall outlet is if the owner wants to be able to flip the switch back on at the wall outlet instead of going all the way to the breaker box to switch back on or if the wall outlet you’re going to use doesn’t have a breaker in the box.

Why would you make a post that is so incredibly wrong? I know you are trying to help, but if you don't know then it's better to not say anything.

Every outlet is not on it's own breaker. A breaker and a GFCI are totally different.

This is really important stuff. Please don't lead people in the wrong direction.

 

[Brew12]

(I love what you have posted, @Brew12 “He who asks a question is a fool for five minutes; he who does not ask a question remains a fool forever.” - Chinese proverb.)

... And so to boil it down for us 'five-minute-fools'... If I just plain-old don't want to get z-a-p-p-e-d, should I have a grounding probe in my tank, a GFCI, both, or dare I ask: A grounding probe plugged INTO a GFCI? Thanks in advance.

I use a ground probe GFCI combination. It does not matter where you plug the ground probe in. You could plug it into your neighbors house and it would work the exact same way.

 

[Brew12]

Good point about saltwater being more conductive. Now you have me thinking about my pond. If the pump wire somehow leaked voltage I wonder if it would shock me then pop the gfci as now I am the ground path?

It probably wouldn't happen when you put your hand in the pond. Unless you have a lot of dissolved minerals in your water you probably wouldn't get zapped unless you grabbed the cord/pump at the location of the fault. The the GFCI should trip and protect you. Always a good idea to unplug anything in fresh water before touching it, but you are pretty safe leaving things running if you only put your hand in the water.

 

[kcschwabe]

Well..I stuck my hand in my saltwater mixing tank last week and learned very quickly that my cheap ace Amazon special power head was leaking electricity. So there’s that…

Ok then sounds good I guess my tank and a good then lol

 

[Kasey Grohowski]

So these can be put in with livestock already in tank correct? Just plug in and drop probe in sump?

 

[capted]

So these can be put in with livestock already in tank correct? Just plug in and drop probe in sump?

Yes. But if there is stray voltage and you are using a gfci outlet it may pop and shut the power. But that's a good thing!!

 

[Paul B]

You can have GFCI circuit breakers but they aren't nearly as common.

Good Morning Brew my good Buddy.
I think you made a "little" mistake here:

All GFCI circuit breakers are circuit breakers (overload devices) "and" GFCI devices. They will trip on an overload and a ground fault. But that is neither here nor there.

One interesting fact that almost no one knows about house wiring is that the old plug fuses were much safer than today's circuit breakers. Of course they don't have any protection for ground faults but circuit breakers replaced plug fuses long before GFCIs were invented.

A plug fuse blows instantly on any overload which made them a pain as they were very sensitive and even a motor starting would blow them.

Modern circuit breakers are hundreds of times more expensive than fuses but much more convenient.

As a Journeyman electrician in Manhattan I installed and worked on thousands of breakers over almost 50 years and "before" circuit testers were invented, to find a circuit we would just short it out with a paper clip, screwdriver or apprentice.

Then we would go to the breaker box and find the tripped breaker. With some breakers you would almost have to burn the place down before the breaker tripped.

There was a company called "Federal" which made many of the breakers in new buildings and they would hardly ever trip as the wires would melt before the breaker tripped so we didn't short those out. They are fortunately out of business now.

Just yesterday I had to replace a GFI breaker for my kitchen. The thing kept tripping on a ground fault with nothing plugged in. I got one at LOEWS because my supply at home ran out. I couldn't believe they are now almost $60.00. Not long ago they were $12.00

 

[powers2001]

@Paul B P LOL we still have some plug fuses in place on our farm buildings. We just recently replaced plug fuses with circuit breakers in our pump house. LOL

 

[capted]

Ha, I still know a house with scew in fuses. I used to pop them all the time with an air compressor!! I had boxes of them just for that reason.