How much is too much?

[scottwhitson]

Stray voltage that is? Our tank just hasn't been doing as well lately we have been fighting some different issues but thought that I would check for stray voltage and found 8.5V of voltage running through our tank. :eek1: I would assume that this could be an issue but wanted to see if anyone else has issues with low voltage leaks?

 

[reefergeorge]

I say it's induced voltage. Everything including your lights will add to this number. You can either add a ground probe or not, but make sure to have everything on gfci outlets.

I personally have around 30 volts in my 90. 10ish in my 12.

 

[slief]

I say it's induced voltage. Everything including your lights will add to this number. You can either add a ground probe or not, but make sure to have everything on gfci outlets.

I personally have around 30 volts in my 90. 10ish in my 12.

30 volts?? If you could tap into that to drive a light or power head, you'd be genius! At that rate I could run the vacuum off my tank. I need to bring my multimeter home from work. This has me really curious. Gives a whole new meaning to Electric Eel.

 

[Mad_Reefer]

I had 38-39 in my 180 and I found that my heater was adding 29 so I removed the heater.
I think the numbers can be different based on how you make contact with the water so you just want to look for something that causes large amounts relative to the total.

 

[luther1200]

I tested a while back and had a high number also. In the 30's I think. So I unplugged everthing in the water one at a time and it had no affect. So I think it was the lights, and never really worried about it since everything looked/looks fine.

 

[Fish Ace]

Try unpluging everything then test, it wouldn't supprise me to see some sort of voltage.

 

[Sikryd]

+1 on the lights adding to the total. Its probably induced.

I would test and unplug everything just to make sure it isn't a heater or a powerhead.

 

[msobon]

Just a side note, what are you using to test your voltage in the tank, with a multimeter i would suggest also measure the current of the "stray voltage" and also if you are using any probes that you stick in the water will cause a current given that salt in water is a solution but shouldnt be 30+ volts

 

[Calif-Reef]

Couple questions, how do lights add voltage to the water and how do you ground your tank.
Thanks
mark

 

[iwishtofish]

Couple questions, how do lights add voltage to the water and how do you ground your tank.
Thanks
mark

Another question: Will a grounding probe in any way inhibit a GFCI from tripping?

 

[TP123]

Another question: Will a grounding probe in any way inhibit a GFCI from tripping?

shouldn't.

 

[reefergeorge]

Just a side note, what are you using to test your voltage in the tank, with a multimeter i would suggest also measure the current of the "stray voltage" and also if you are using any probes that you stick in the water will cause a current given that salt in water is a solution but shouldnt be 30+ volts

I checked with my voltmeter. I also put a resistor in series with the ground probe, and still got my 30 volts. I'll have to check the resistance again to figure out the current.

Every pump in my tank added 2-5 volts. The lights added 10ish. I'm not worried about it. If I ever feel a tingle I'll make a PSA.

 

[reefergeorge]

Another question: Will a grounding probe in any way inhibit a GFCI from tripping?

Don't ever use a ground probe without a gfci. Breakers alone are not meant to protect people.

 

[LobsterOfJustice]

Here's a post I made on the subject in another thread this week:

I've always read way more than 8v. Furthermore, it seems like every piece of equipment contributes a few here and there, so I cant eliminate it by replacing any one thing. Even more confusingly, some things lower the voltage when plugged in, and things give different voltage readings when plugged in at the same time as other things (not just a sum of individuals).

I've started a number of threads tring to find a threshold of how much voltage is too much, but cant get a straight answer. Just two days ago I was getting a shock and tested, got about 34v. I cleaned salt spray off some cords and got it down to 17-24v.