How much stray voltage is harmful?

JasonK84 · Jan 21, 2020

Just like the title says, how much stray voltage before fish start to be affected? I lost an Aussie Tusk a couple weeks ago and a professional necropsy resulted in nothing out of the ordinary. Yesterday I came home from work and my pink face wrasse was dead and stuck to a powerhead. As soon as I got off work today I ran to the hardware store and bought a volt meter to test for stray voltage.

I have 2 volts (already ordered a titanium grounding probe) reading on the meter. Could that be enough to lose fish from? Are wrasses more sensitive to stray voltage than others?

About the same time the Tusk quit eating normal was around the same time I replaced my powerhead. The pink face wrasse never quit eating and never acted strange. I’m about to unplug the powerhead and retest for voltage to see if that is where it is coming from but wanted to check here to see if 2 volts could be the cause of my issues.

Harlequin Tusk necropsy report:

Euphyllia97 · Jan 22, 2020

I have heard anything from 0-30 volts is considered a normal value without any probe. 2 volts shouldn’t be a problem. Try to find which piece of equipment is releasing the voltage as it could be the start of a failure.

Had a heater failure a couple of months ago releasing 120 volts in my tank For the whole day. Fish and corals haven’t been affected. As long as there is no path forthe voltage to go, there will be no current and your fish probabely don’t even notice if it is not a high value.

A grounding probe is a good idea for your own safety however.

Paul B · Jan 22, 2020

Most tanks will have stray voltage of about 20 or 30 volts. That would not kill anything but no one knows what stray voltage does to a fishes nervous system.

If a tank such as yours with no ground probe shows 2 volts, it really has no voltage actually going through the water. You are only reading it because you put a voltage meter in there so the electricity has a path to go, through the meter.

With no path to ground, there is no electricity going through your water or your fish.

We use ground probes for "our" safety, not the fish.

As a matter of fact, all the electricity produced on Earth travels back to the power station through the earth and seas.

Electricity did not kill your fish.
(Master Electrician 50 years)

JasonK84 · Jan 22, 2020

Paul B said:
Most tanks will have stray voltage of about 20 or 30 volts. That would not kill anything but no one knows what stray voltage does to a fishes nervous system.

If a tank such as yours with no ground probe shows 2 volts, it really has no voltage actually going through the water. You are only reading it because you put a voltage meter in there so the electricity has a path to go, through the meter.

With no path to ground, there is no electricity going through your water or your fish.

We use ground probes for "our" safety, not the fish.

As a matter of fact, all the electricity produced on Earth travels back to the power station through the earth and seas.

Electricity did not kill your fish.
(Master Electrician 50 years)

That was the reason for the question actually because I didn’t feel like 2 volts was much of anything. Thanks Paul. Been needing to get the tank grounded anyway.