Stray voltage

EW_Fish · Feb 17, 2014

I have read many threads on this but not finding a clear answer on if it affect corals.
I have been keeping a sps dominate reef for 3 years now and after I moved I started losing sps. (looks like alk burn) But all my parms are stable and right. Well tonight I brought home a multimeter and tested. + in the tank and - in the ground socket. My reading was 30.4v on a 30g AIO tank. I tried to see which item was putting out stray current but looked like everything was even my brand new ehiem jager heater. So I thought I was doing it wrong. I got my voltage light up pen out and stuck it in the water and it was going off. I ran it out of the water on top of the surface to see if it was picking something else up but no light up. Any ideas here? My sps has no PE and I lose them within a week sometimes over night. I have been running circles trying to figure out what I'm doing wrong but everything is right

joekool · Feb 17, 2014

Did you try unplugging each electric item in your sump at a time and test until it goes away. Try that. Personally the only thing in my sump water is my heater and its only on when apex turns it on. Also I run a grounding probe in my sump to catch any stray voltage. Not sure what your setup is in he sump but unplug test unplug test etc.

I would go external return pump and external skimmer so no worries.

EW_Fish · Feb 17, 2014

I have a 30g AIO I tried unplugging each one they all have voltage even the new heater
1-return pump
1- 9002 tunze skimmer
1- 100w jager heater

Fuge light
display light (leds)

spspirate · Feb 17, 2014

Most reef systems are going to have stray voltage to some degree is what I understand. I just don't know how much is too much. Ill try to do some searching Josh.

EW_Fish · Feb 17, 2014

I saw over 40v is bad but havent gotten a clear answer. My sps just die lol. Never had this problem

Reefltx · Feb 17, 2014

Do you get a shock when you touch the water?
I tested mines about a week ago got 0 and I have a lot of gadgets running.

salmonshutters · Feb 17, 2014

I just checked my voltage in my tank and at first I was getting readings around .06-.15V, so having 30+ volts scares me in my eyes. 120V is pretty hard on a human, now imagine what 30 V could do to something as small as a fish.

EW_Fish · Feb 17, 2014

salmonshutters said:
I just checked my voltage in my tank and at first I was getting readings around .06-.15V, so having 30+ volts scares me in my eyes. 120V is pretty hard on a human, now imagine what 30 V could do to something as small as a fish.

Yeah I know right

EW_Fish · Feb 17, 2014

Also did you make sure the probe was in the ground socket well? I was getting a low reading till I connected well then it shot up

salmonshutters · Feb 17, 2014

You should get a drop in voltage by unplugging each item one at a time. You might have a few things adding current to your tank, so it may not drop completely from unplugging the culprit.

EW_Fish · Feb 17, 2014

I said I was getting something from each item. what I don't understand is i'm getting voltage from 2 items that are brand new

salmonshutters · Feb 17, 2014

Could a surge protector cause something like this?

spspirate · Feb 17, 2014

Thats normal if its just a little. 10v-12v is ok I believe of course 0.0v is what you want. Do you know how many volts each one is putting out?

EW_Fish · Feb 17, 2014

18.4v return pump
12.1v skimmer
8.3v heater

with all 3 plugged in 26.2v

EW_Fish · Feb 17, 2014

heater and the skimmer are new....

bct15 · Feb 17, 2014

That is fairly normal, your are not seeing stray voltage you are seeing induced voltage...it essentially comes from the magnetic field around the device. That is why your pump puts out so much.

EW_Fish · Feb 17, 2014

bct15 said:
That is fairly normal, your are not seeing stray voltage you are seeing induced voltage...it essentially comes from the magnetic field around the device. That is why your pump puts out so much.

Thanks

salmonshutters · Feb 17, 2014

idk if I agree with that, it just doesn't make sense to me.

bct15 · Feb 17, 2014

salmonshutters said:
idk if I agree with that, it just doesn't make sense to me.

http://en.wikipedia.org/wiki/Electromagnetic_induction

http://www.theaquariumwiki.com/Stray_current

I gave you a couple links to read, but there is a bunch more to read about it online. Basically what is happening, is your pumps an powerheads have spinning magnets that are submerge underwater, and all will induce a voltage to the tank. This voltage has no current, which is what you are worried about. The voltage is just a measure of the potential for current to flow. Because the induced voltage has no current it isn't a problem. It isn't the same as a stray current that would come from a short circuit in your tank, and supply current from the wall socket. A ground probe won't fix that.

Whys Alives · Feb 17, 2014

bct15 said:
That is fairly normal, your are not seeing stray voltage you are seeing induced voltage...it essentially comes from the magnetic field around the device. That is why your pump puts out so much.

^^^ This.

Light fixtures are especially good at inducing voltage, I've noticed.

Tho it has probably been said, for reference, it only takes 21v to conduct electricity thru a human being. A grounding probe will not keep you safe and it is imperative to have a GFCI on any outlets servicing your aquarium.