Is This Stray Voltage

[Brew12]

In the case of fish I think it has more to do with the fields around the fish than any current flowing anywhere.

Completely agree. I just wish I understood more about how the field interacted with the fish and if the voltage of the tank in relation to ground mattered.

I was once in a house where the carrier had broken for the electric service and the ground outside for the service entrance was broken. I had to get some wire and make my own ground with a screwdriver in the dirt to fix their service. The outside of the stove was energized. All the loads in the house where working through some path to ground that wasn't obvious.

Sounds like the neutral was still connected. When it comes unbonded from ground the first thing most people notice is that some lights get brighter when a large load like a washing machine or hvac unit starts. Unfortunately, this key indicator doesn't work nearly as well without the old style incandescent bulbs. I feel that house fires due to open neutrals like this are going to become more common.

I trust my meter and nothing else when it comes to electricity. It is truly herding cats. Viscous ones that can bite you.

Agreed with this, too. And I check my meters often.

 

[ltrace]

Just sticking a voltmeter in won’t show anything. Voltage is the *difference* in electrical potential between two states (live and ground). To measure if your tank has stray voltage, put the black probe into the ground hole of an outlet, and the red probe in your water. Then it’ll show a value.

Alternatively, just preempt all of that messing around trying to find the source and put in a grounding probe. It connects ‘the circuit’ between whatever is leaking voltage to your house electrical ground.

If it was me though, and it was that noticeable, I’d identify the equipment that is to blame and replace it.

When use the voltmeter would you set it to AC or DC?

 

[WVNed]

AC

 

[ltrace]

Thank you @chipmunkofdoom2 for answering my question at AC DC. Also thank you @neilp2006 for instructions on how to use the multitmeter because I was using it incorrectly. Now can anyone tell is zero the number I would want to see on the meter?

 

[ltrace]

Can stray voltage kill coral and invertebrates and not harm the fish in the tank? I ask because the last 3 months things have been dying off. Started with colt coral, then galaxea, zoas, anemone, candy cane, snails, cleaners shrimp, crabs. Toadstools are suffering but still living. Mushrooms are flourishing. Monti it doing okay. The Royal Gamma, Elibli Angel, 2 ice clowns, sleeper goby and lawnmower blenny are doing fine.
Nitrates 10-15
Phosphates .03
Mg 1250
Ca 420
Alk 7.7
ph 8.2
lights are Reefbreeder Superlux they were running at 30% but now are at 50%.
Any other suggestion will be helpful.

 

[Brew12]

Can stray voltage kill coral and invertebrates and not harm the fish in the tank? I ask because the last 3 months things have been dying off. Started with colt coral, then galaxea, zoas, anemone, candy cane, snails, cleaners shrimp, crabs. Toadstools are suffering but still living. Mushrooms are flourishing. Monti it doing okay. The Royal Gamma, Elibli Angel, 2 ice clowns, sleeper goby and lawnmower blenny are doing fine.
Nitrates 10-15
Phosphates .03
Mg 1250
Ca 420
Alk 7.7
ph 8.2
lights are Reefbreeder Superlux they were running at 30% but now are at 50%.
Any other suggestion will be helpful.

I doubt that the voltage itself can. Stray voltage comes in 2 main types. Induced voltages from magnetic fields from our equipment which is less of a problem. The other possible source is a fault voltage from a piece of damaged equipment. This voltage isn't likely to be a problem but it could mean you have exposed copper or other contaminants being released into your system which would impact inverts more quickly than fish. Using a GFCI with a ground probe makes it easy to see if you have a failing piece of equipment.

 

[pecan2phat]

Great debate/info guys, learned quite a bit!

 

[ltrace]

I doubt that the voltage itself can. Stray voltage comes in 2 main types. Induced voltages from magnetic fields from our equipment which is less of a problem. The other possible source is a fault voltage from a piece of damaged equipment. This voltage isn't likely to be a problem but it could mean you have exposed copper or other contaminants being released into your system which would impact inverts more quickly than fish. Using a GFCI with a ground probe makes it easy to see if you have a failing piece of equipment.

This is a tank for our school and the electrician put in a GFCI circuit. So every electrical device goes through that circuit. How would I test the individual device for failure?

 

[Brew12]

This is a tank for our school and the electrician put in a GFCI circuit. So every electrical device goes through that circuit. How would I test the individual device for failure?

Do you have a ground probe installed in the system?

 

[ltrace]

Do you have a ground probe installed in the system?

No I do not. Should I get one?

 

[Brew12]

No I do not. Should I get one?

I would recommend it. If you have a ground probe installed it will cause the GFCI to trip as soon as a piece of equipment fails. No further testing required.

 

[ltrace]

the only electrical devices in the tank were 2 power heads and a heater and I have changed those out. Assuming that I should get a grounding probe, should I put the original devices back in to see which one possibly failed?

 

[Brew12]

the only electrical devices in the tank were 2 power heads and a heater and I have changed those out. Assuming that I should get a grounding probe, should I put the original devices back in to see which one possibly failed?

I would. That way you know if they are safe to use as a back up in case one of the new ones fails. Even easier, you can run them in a bucket of salt water, plugged into a gfci, with the ground probe in the bucket. You can test them that way without putting them in the tank.

I keep one of these near my tank so I can test things without impacting my system.
https://www.lowes.com/pd/Shock-Bust...ngle-to-Single-Yellow-GFCI-Adapter/1000492081

 

[ltrace]

Hope this is not a dum question but how do you use it? Would I need both this and the grounding probe?

 

[Brew12]

Hope this is not a dum question but how do you use it? Would I need both this and the grounding probe?

A GFCI trips if current between the hot and neutral connections doesn't match. The assumption is that any other current must be going to ground.

Glass and acrylic are great insulators so there may not be a ground path for current to flow through. A ground probe provides this ground path.

So yes, they both serve different purposes and you would want both imo. The ground probe is very easy to use. Plug one end in anywhere put the other in the water of your tank.

 

[ltrace]

Thank you so much for your help. Our school students will thank you as well.

 

[User]

Thank you @chipmunkofdoom2 for answering my question at AC DC. Also thank you @neilp2006 for instructions on how to use the multitmeter because I was using it incorrectly. Now can anyone tell is zero the number I would want to see on the meter?

Glad I could be of some help.

 

[Paul B]

To answer your question, yes it is induced voltage. Go out to dinner and forget about it, your fish already did.
I don't eat paint chips. To save time so I don't have to wait till it dries, I drink paint right out of the can.

 

[PirateDan]

OMG!!!! Will you two just let it go!!!