How much stray voltage is tolerable?

[jsodwi]

So I decided to check for stray voltage because the pipe heater I use in the winter to keep the drain on my auto water changer is getting old and I didn't want any electricity to run back into the sump. As it turns out, when my heaters kick on I'm getting about 1 volt running thru the tank. To us that small amount is nothing but how much is tolerable to aquarium inhabitants? I have no clue how long this has been going on but the heaters are all titanium and under a year old.

 

[Drstrangelove]

I would prefer none. I found a report that says that even cows will detect 1 volt and demonstrate avoidance behavior. One volt might not kill your fish, but might affect long term health.


http://www.uwex.edu/uwmril/pdf/StrayVoltage/03_What_do_we_know_about_Stray_Voltage.pdf


The bigger issue is whether or not 1 volt might become something much larger and perhaps affect you. Not an electrician, but my preference is none.

 

[jsodwi]

Yes Id prefer none as well. I'm going to unplug each heater an hope it goes away. Maybe one of them is defective.

 

[duanes]

Because fish aren't grounded, there is a theory that they may be unaffected by slight voltage.
But there is also a theory that although they aren't electrocuted by it, that it does cause a certain amount of stress.
If you can't find, or change whatever is causing it, there are titanium grounding probes available that are inexpensive, and are a temporary solution.
They can also save you from getting a large shock, and even heart attack in case the voltage takes a turn for the worst.

 

[jsodwi]

I unplugged each heater one at a time. It seems like they all put a slight amount of voltage in the tank. Now my meter is not the greatest so I don't know how accurate it is. But maybe I'll try out the ground probe.

 

[boldtogether]

0 voltage is acceptable.
Any voltage, not so much.
Remember, water is a very poor conductor of electricity, so worrying about stray voltage is easily remedied by the addition of a grounding probe....
I have had significant voltage detected in the tank disappear completely with grounding probes.

 

[Yoda1]

And if you put your hands in the tank.......

 

[duanes]

While I agree it is most likely the heaters, pumps, or even lights can be the culprit.
Try unplugging all the heaters to see if its still there. Then the rest, one at a time.
There is a diagram in the tech mag "Pumps, and Pump systems", that shows how to put your hand in water with voltage to lessen it traveling thru the heart, might be worth looking into.
If I find it, I will add it to the thread.

 

[spotfin]

With a grounding probe, does it make a difference if it is the main tank or the sump?

 

[joe jaskot]

An aquarium ground probe won’t protect you from electrocution. You must have BOTH a ground probe and a GFCI.