HELP! Likely stray voltage

[rogeragrimes]

120-gal tank with reef and fish. I have several electronic devices inserted into the tank or 30-gal sump, including two water movers, sea swirl, heater, water pump, ATO, and mixed GTO reactor.

Is any voltage above 0 bad?

I noticed that my Toadstool Leather coral, possibly Sarcophyton glaucum, started looking very poor two days ago out of the blue. I felt some small current when I touched the water on my arm hair and in a small wound. Got my regular voltage meter and put the red/hot probe in the water and black/ground probe on a screw on a nearby light switch.

With everything in-plugged I have little to no current. If I plug in my two water movers, I get about 2-3 volts detected (using that method above). If I plug everything back in the voltage climbs to about 20v.

Is anything above 0 volts too much? Or I'm wondering does each electrical device submerged into the water carry some nominal expected and normal voltage?

 

[mcgyvr]

NO...
Forget you ever heard the term stray voltage.. What you are seeing is 100% normal and not indicative of an issue..
Specifically see post #9 and #12
http://www.reefcentral.com/forums/showthread.php?t=2627113

and remember...
ALL line powered (AC) equipment MUST be installed on a GFCI device (that could be one that just plugs into the existing outlet or a replacement outlet or a replacement breaker for the circuit).. But it must offer GFCI protection.. Surge protection is NOT the same thing..

That device will potentially save your life and can be had for as little as $20..

 

[rogeragrimes]

Thanks. Yes, it is GFCI protected.

 

[mcgyvr]

Some good GFCI devices to have..

Adapters.. Simple.. No electrical knowledge required.
http://www.homedepot.com/p/Defiant-GFCI-5-Outlet-Adapter-30339037/203741442
http://www.homedepot.com/p/Defiant-Plug-In-GFCI-Adapter-3-Wire-Grounding-30339036/203741464

Or you can just swap out the existing outlet for something like this.. (electrical skills required. requires turning off breaker to outlet)
http://www.homedepot.com/p/Leviton-...lim-GFCI-Outlet-White-R72-GFNT1-0RW/205996720

Or replace the whole circuit with something like this.. (electrical skills required..requires turning off main breaker to house for safety so that the panel board can be worked on safely)

(this is 20A.. 15A would also be very common/available and you should not install a 20A where a 15A breaker was as this requires running new electrical lines)
http://www.homedepot.com/p/Square-D...le-GFCI-Circuit-Breaker-HOM120GFICP/100002959

 

[mcgyvr]

Oh and its VERY common for leather/soft corals to close up/shed skin/drop arms,etc..
All are normal and may last a day or 2 to a week or more sometimes..
Thats how it reproduces and shedding is to remove algae from the surface of it..

 

[rogeragrimes]

Oh and its VERY common for leather/soft corals to close up/shed skin/drop arms,etc..
All are normal and may last a day or 2 to a week or more sometimes..
Thats how it reproduces and shedding is to remove algae from the surface of it..

Thanks. That did happen once before to a small toadstool and it "recovered". Thanks. It was the toadstool condition plus the light current I'm feeling that got me worried. Seems it's normal.

Thanks for your reply.

 

[mcgyvr]

Not a bad idea either to routinely use the "test" button on the GFCI unit to ensure its working properly too..

But feeling a tingle on a cut with saltwater is normal..
Its the salt..
And a GFCI will shut down the system in the event of an real issues (current flow not balanced between line and neutral)

 

[Cardmines52]

I am also curious about that.

 

[LobsterOfJustice]

A little voltage is normal. Test the voltage while unplugging items one at a time. If you can isolate a single item responsible for a large drop, consider replacing that item if you can. Otherwise, if each item contributes 1-3ish volts, don't worry about it.

 

[mcgyvr]

A little voltage is normal. Test the voltage while unplugging items one at a time. If you can isolate a single item responsible for a large drop, consider replacing that item if you can. Otherwise, if each item contributes 1-3ish volts, don't worry about it.

I usually state that if you do measure anything less than 1/3rd line voltage then it should be ignored and treated as normal.. (so with 120V service anything under 40 volts should be ignored)
Anything above that and you might want to start looking for a problem..
But thats really what the GFCI will protect you from anyway.

 

[rogeragrimes]

Thanks everyone

 

[ReefHog]

But feeling a tingle on a cut with saltwater is normal..
Its the salt..

Yes but not always. I felt the "tingling" on a cut in my sump and plugged in a grounding probe to see if that would make a difference. It did. When the grounding probe was in the water column, no shock/tingle. Pull it out and the shock/tingle was back. I unplugged my equipment one by one until i found the culprit. The pump to my gfo reactor. replaced the pump and no shock/tingle with no grounding probe.

 

[rogeragrimes]

Yes but not always. I felt the "tingling" on a cut in my sump and plugged in a grounding probe to see if that would make a difference. It did. When the grounding probe was in the water column, no shock/tingle. Pull it out and the shock/tingle was back. I unplugged my equipment one by one until i found the culprit. The pump to my gfo reactor. replaced the pump and no shock/tingle with no grounding probe.

Thanks for the idea.

 

[joshbrookkate]

Following....
Is it a good idea to keep a grounding probe in my DT and/or my sump? I am using GFCI protected extension cords.

 

[mcgyvr]

A grounding probe will just make sure your GFCI trips the instant a problem develops..
Which could mean when you aren't home,etc...

As long as you are using it with GFCI devices then use it if you want..