Stray Voltage talk

[UCF Alum]

I know this has been talked about before, but I’m bringing it up again.

I had to stick my hand in the tank tonight. I have a small cut on one of my fingers. I know the feeling of a cut when it’s stuck in salt water, but this was something totally different.

For the heck of it, I got out the multimeter. I held the ground side of the prong in my hand and stuck red end into the tank. There is a fluctuation of .03-.05v running through the water consistently. All but two of my pumps are DC. The AC pumps are Sicce that run my reactor and UV sterilizer. I do not see any other exposure of electronic devices to the aquarium water.

Have any of you done this test and are you aware of any potential adverse effects to the livestock? When I stick my hand in without a cut on it, I feel nothing. (I always avoid sticking the cut up hand in the water but both of them are banged up from yard work this past weekend).

Has anyone come across conclusive evidence of this being a problem?

Your thoughts, ideas and theories are all welcome.

 

[sandswhitson]

You should give your multimeter a good ground and see what it reads then. Stick the black probe in the ground hole of your wall outlet and the red one in the water. FWIW if you dont have a grounding rod/probe in your tank then there is no path for current to flow so no harm to anything in the tank.

 

[redfishbluefish]

First off, it's the cut!

Secondly, I've never seen voltage that low....you're very lucky.

There are two voltages in our tanks...

Stray and Induced

Induced is from magnets spinning in a coil....from pumps and powerheads. This voltage, which could be high, is not dangerous.

Stray voltage is from frayed wires or faulty equipment...and is the dangerous voltage.

Now I've said that as an electrical dummy....so let's have @Brew12 comment....the electrical genus here.

 

[Brew12]

There is a fluctuation of .03-.05v running through the water consistently.

This is extremely low, I'm guessing you run a ground probe or titanium heater.

All but two of my pumps are DC.

DC pumps run on some form of AC wave. They are only called DC because they convert AC from the wall to DC, then back to some controllable form of AC. They will both induce an AC voltage and read as an AC voltage in the tank if they fail.

Have any of you done this test and are you aware of any potential adverse effects to the livestock?

This is such a tough question. I'm not aware of any conclusive tests that were done. I can say with some confidence that current will not harm a saltwater fish at the levels it could occur in a house. The fish is much less conductive than the water around it so most current will flow around the fish. I haven't seen anything conclusive if voltage can impact a fish. Some suspect it causes HLLE, and I recently heard it could make fish appear disoriented.

When I stick my hand in without a cut on it, I feel nothing

It could be a reaction between the salt water and the cut. It could also be that skin has some resistance to it, so the cut allows enough current to flow to be felt.

Your thoughts, ideas and theories are all welcome.

If you have a meter that can read current, I would take a current reading between your water and the ground connection of an outlet. If you see more than 0.1 amps you have a voltage issue.

 

[UCF Alum]

This is extremely low, I'm guessing you run a ground probe or titanium heater.

Neither. Ehiem heater (does not kick on here in Florida until winter) and it was off. I do not use a ground probe. I can run a current test, but my probe wires aren’t long enough.

The “sensation” I get from my finger in the tank compared to sticking it in plain saltwater is different. Hard to describe, but if I had to, I’d say it’s “pins and needles.”

 

[Brew12]

Neither. Ehiem heater (does not kick on here in Florida until winter) and it was off. I do not use a ground probe. I can run a current test, but my probe wires aren’t long enough.

The “sensation” I get from my finger in the tank compared to sticking it in plain saltwater is different. Hard to describe, but if I had to, I’d say it’s “pins and needles.”

You can use an extension cord to get the ground closer to the tank and it should work.

I've heard of some people who are extremely sensitive to electrical voltages, you may be one of those rare cases.

 

[Dom]

In the end, I think using (or not using) a ground probe in your tank is about personal priorities. I use a grounding probe.

For me, it is about safety first. I have kids that come to the house regularly. And kids can be mischievous. If that mischief leads to them sticking their hands in the sump, I'd rather deal with the consequences of their hands in the sump than the consequences of electrocution.

In my view, that outweighs any arguement for not using one.