Stray Voltage - Fact or Fiction

MnFish1 · Aug 23, 2019

One thing that is usually mentioned when someone is having a problem with their tank/fish/coral is 'stray voltage'. If one reads through the literature many people say (though it can cause damage to humans - it should not damage tank inhabitants - except in certain specific circumstances. What does everyone think?

Note - Not asking about potential harm to people if a live wire is in a tank (thats pretty clear). Comment in the comment section

UCF Alum · Aug 23, 2019

Stray voltage, from what I’ve read, can definitely be a contributing factor to HLLE. I say this because my scopas tang has it and when I added a ground probe it started to clear up.

Not sure if it’s coincidence or not, but nothing else changed when it started to get better.

alton · Aug 23, 2019

Stray Voltage to me is induced voltage cause by lamps, electric pumps in your tank. There is no current in the tank so it is not bad for humans. I have seen up to 50 volts in a tank with no current. Having Current in your tank is bad for everything because you now have a piece of equipment failing and can leach all sorts of bad things in your tank, plus cause possible injury. Back to stray voltage and I have a testimony of a fish store owner

(From Richard at CB pets)

We know from experience that certain fish may do poorly in tanks which have stray voltage. One example is an imperator angel we had in qt that was doing really well. Moved him out for sale and all he did was hide in the corner and would not eat. Moved him back to qt and he acted fine. Moved him back out and he quit eating. Hmmmm...so I checked for stray voltage on the tank and it was 16 volts. Added a grounding probe and he immediately started swimming around normally and ate when I fed him. So I took out the grounding probe and he immediately swam to the same corner and would not move. Put it back in and he was back to acting normal.

And now a little warning for grounding probes;
If your service ground is bad outside it will use your tank as a ground and you will get more than a tingle. Example I got a call from a friend and he told me he was getting shocked when he put his hand in his tank. So I took a voltage reading and only 5 volts to the meter but to the hand it wasn’t very pleasing. Took out the grounding probe and voltage and shock was gone. I went to the service and added another ground rod and it took care of the problem. He left the probe out of his tank

If you are going to use a grounding probe make sure your service ground is adequate and always use multiple GFCI receptacles or breakers, keeping your main return pump on its own protection.