I have stray voltage

H

hdevils

New member
was wondering why my fish have been acting different. hiding under rocks/ in the corners...

tested my water for voltage and im coming up with a reading of .4 i un plugged everything to make sure i was doing this right and im still getting 00.4??

i tested a glass of water and i get 00.0

dont know much about elect. if everthing is off why do i still get a reading of .4? is it because the equiptment is still in the tank?
 
i have found where the voltage is coming from...

with everything on and running im getting a .4- .6 reading
soon as i take down the lights the volts go down to .0

now my question is how are the lights making elect. in the tank when no part is touching the water?
 
do you get a shock when you put your hand in the tank? the fish are not getting shocked as they are grounded.
 
i didnt notice any shock.

once whatever it is making the voltage is removed. should the voltage drop to 0 or will it take a while for it to drop to 0?
 
I would suggest going to lowes and buying the plug in style and then stuff in the gfci this will prevent electric shock... better safe the sorry
 
no but a ground prob will help as well. Either way i think you probaly need to adress the problem by fixing it instead of buying something else. I honestly do not see how a light fixture with nothing touching the water, can produce current in the water. Kinda strange.
 
my bet is that the high voltage of lights is messing with your meter. put your lights over your glass of water and you should get the same voltage.
.4 is so tiny I would not even worry about that at all.

Just for saftey though get the equp. on a GFCI asap.
I can almost get .4 volts just by sticking the probes on my tounge.

~Steve~
 
the gfci will just shut down if there is large enough of diffrence and pervent some one of getting electric shock... like the one in bathrooms and kitchens. I only suggested the plug in type over the direct wiring in case you have no exp. in wiring and it might be hard if u need to move the tank to gt to the outlet to re wire. but I think this is a very important safty measure. listen how much voltage do you think is runing through your system. protect your family
 
The stray voltage from your lights is due to induction. The lights are runing on AC and have a fairly high wattage, and your saltwater is a conductor, so the AC current above the water can induce a voltage within the saltwater w/o making any contact.

The fish inside your tank are not grounded (unless you did something); they're more like on a floating potential. So, the stray voltage is not dangerous for your fish, because there is no current flowing through their bodies (it's the current that kills, not voltage). If you use a ground probe, you'll be actually forming a closed circuit and you'll have current, literally, flowing through your water. That actually might kill your animals depending on its strength.
 
ok.. so if i understand Lake75 i may have voltage in the water but not current running thru it.. which that would kill the fish.?

So even though i have a voltage reading in the water its ok?

i tested the water this morning with all elect off and get a .03 reading. is this normal?
 
I wouldn't worry about the small reading that you have right now.

I don't know how much voltage is "normal" in saltwater w/o any electrical parts in there, but I wouldn't be surprised that you got some reading. Saltwater is an electrolyte solution. Whenever two different metals are in contact with an electrolyte, you'll have a battery formed and current flowing. The probes of your multimeter are made of metals and normally they'll have a different metallic coating on them. If the coating isn't dense enough to cover the probe metal, the you get two metals in contact with saltwater, resulting in a battery with a small voltage.
 
last night when i placed the light on the tank the reading was .4- .6, a dramatic increase.

even that no need for concern due to it being voltage vs current?
how would one know the difference when testing?
 
<a href=showthread.php?s=&postid=8134204#post8134204 target=_blank>Originally posted</a> by TX26257
I would suggest going to lowes and buying the plug in style and then stuff in the gfci this will prevent electric shock... better safe the sorry
Click to expand...

i agree !!!
 
I don't think you need be concerned with the small voltage reading in your syetem.

With all my lights on (3x175W halides), chiller, skimmer AND a titanium ground probe, I read 670mV. The reason I got the ground probe years ago on my first tank (a 40 breeder) is that I ocassionally felt a mild shock in the main water column.

The mild shock was being caused by about 40VAC stray voltage. The ground probe took it to near zero, but I guess it would maybe take a lot better ground that one can feasibly supply to reach absolute zero potential.

Is it possible that something else could be spooking your fish??
 
<a href=showthread.php?s=&postid=8136041#post8136041 target=_blank>Originally posted</a> by hdevils
last night when i placed the light on the tank the reading was .4- .6, a dramatic increase.

even that no need for concern due to it being voltage vs current?
how would one know the difference when testing?
Click to expand...
Difference of what? If you're not purposely grounding your tank, then you'll definitely have only voltage, not current.

Really, I don't think you should worry about this small stray voltage or even a small electrical current. In fact, there're tons of ions in saltwater (that's why they're conductive); their free movement does create localized electrical current and that has no ill effect on fish/corals.

If you really want to reduce the induction from your lights, you have an option here: Are you using glass shields between your lights and water? Then you can place a metal mesh (e.g. copper) between your light and the glass. This will act as a shield and contain the electromagnetic field. The mesh holes can be fairly large (e.g. 1") and the wires very thin, so it won't cut off your light output by any meaningful amount. --I don't know if anyone has done this before, but theoratically it's a solution.
 
im at a total loss of what can be spooking the fish. i havent witnessed any bullys, water perams are fine, temp fine, all have been in the tank for months, eat like crazy. am i missing something?

there may have been a bully in the tank a 1.5 wks ago. found the angel stuck in a rock head first.
 
hdevils,
Today I experienced the same problem with my CoraLight fixture. I put my hand in the water and got a "tingle" at a cut on my finger. I unplugged everything one at a time, not trying the light fixture until last because my thinking was "Hey, it can't be the lights because there is nothing with the lights in contact with the water..plastic legs (non-conducter) and cords not in contact with tank."

Sure enough, it was the light fixture!

I took the light fixture completely apart to look for a nicked wire, nothing! I plugged it back in and put it on the tank and the "shock" was still there. I unplugged one of the lighting cords, the "daylights" cord, and left the actinics plugged in and sure enough, no "shock".

How does "stray voltage conduct to the water? I am no electrician and am just looking for an explanation of how to prevent this stray voltage.

Thanks,
Jim
 
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