72 volts in my tank!!!

[mikeyfishy]

Have had a problem with fish dying for unseen reasons. For more detail than you'd ever want to know, see:
https://forums.saltwaterfish.com/t/251056/ongoing-saga-all-fish-die-in-days/40
Just tested for stray voltage. One lead on ground, the other in the tank. 72 volts! Confirmed with a second meter, both digital meters: one autoranging the other manual range. Unplugged my heater, 36 volts. Turned the AC plug 180 degrees on the heater and plugged it back in: 34 volts! Started unplugging the three powerheads and filter and each seemed to contribute roughly 7 to 8 volts so the heater was the majority of the problem, but all others seem to contribute.
For now I put a copper grounding rod into the water and it's down to 0.9 volts. I find three mysteries in this:
(1) Why would each appliance contribute as much as 7-8 volts? Doesn't seem normal.
(2) If this is my fish killer, why has it never affected the inverts and why would the fish only start dying after about 6 weeks. They live through the cycle (yes I use damsels to cycle) and then all of a sudden start dropping quickly after 6 weeks with no new equipment added. Plus any new fish added at that point die almost immediately which points away from stray voltage as the cause.
(3) I stick my arm in there to adjust things all the time. Why would I not feel the shock? Maybe it's just not enough amperage and/or I'm not grounded enough?
There are so many threads about stray voltage here, but I've never seen someone report something as high as 72v. Any clues here?
Thanks,
Mike

 

[mikeyfishy]

OK, just measured the amperage with the grounding rod out: 3 microamps. That's 3 ten millionths of an amp. Not sure that's significant enough to affect anything. I'm not even sure how the meter is able to read voltage with that little amperage.
Mike

 

[autofreak44]

wow i think i want to test my tank for stray voltage

 

[b bauer]

test between the hot and ground you should be 120v or really close if they are not you might have a floating ground.that might explain some voltage readings.sorry for the incomplete post my son had a large program running and computer ran slow

 

[seannmelly]

i dont think copper in your tank is a good thing

 

[mikeyfishy]

Originally Posted by seannmelly
i dont think copper in your tank is a good thing
But probably better than 72v until I can get something that doesn't corrode as much! I don't think the copper will be a problem over a day or two.
Mike

 

[sharkbait9]

thats a risk i think i might not want to take

 

[reefkprz]

copper corrodes extremely fast, 24 hours and you'll be seriously polluting your tank. copper toxicity wont just go away when you take the copper out either copper gets absorbed into your rock it could be long term detrimental for a very short term gain.
Titanium is the way to go but, if you need something short term use stainless steel untill tommorrow Wrap the copper wire around a stainless steel object, knife, fork, etcetera. I reccomend getting the copper out ASAP!
I would then look into better equipment, that wont be dumpuing voltage into your tank even with a grounding rod you or something else can get zapped if its a better conduit than the rod.

 

[mikeyfishy]

I have titanium in there now. I had a titanium exhaust flange clamp. It worked perfectly. I put both nuts on one side of the clamp to clamp down the copper wire to the clamp and then just hung the other side over into the tank. Works perfectly and cost me nothing. Another oddity has turned up this morning. When I first tested the voltage with the grounding rod OUT, I got 0.6 volts. I tested several times to make sure the grounding wire was totally out of the water and not touching any other equipment. Still 0.6 volts. By the time I got the titanium clamp ready (about 5 minutes), I tested it again: back up to 36v. I don't think it's a floating ground as when I test the ground, it tests OK. I also know it isn't the equipment when I can unplug each appliance one at a time and each contributes some voltage. It's almost like something is switching on/off causing the problem. Very weird, but I guess with the grounding clamp in, I don't have to worry.
BTW, there was no visible corrosion on the copper overnight. I looked at it and also wiped a cloth across it and there was no visible residue. I don't think it corrodes quite as fast as you think.
Mike

 

[stdreb27]

Now think about this, this thread isn't about the copper, but about the voltage in your tank. Something isn't sealed. That is what you should be worried about. Not how to channel the electricity out into the ground.

 

[seannmelly]

still the copper isnt good for your tank either way

 

[mikeyfishy]

Originally Posted by stdreb27
Now think about this, this thread isn't about the copper, but about the voltage in your tank. Something isn't sealed. That is what you should be worried about. Not how to channel the electricity out into the ground.
Agreed, but when I unplug things one at a time and see the voltage drop 7-8 volts with each item, I tend to think the problem is elsewhere: not in the equipment. How could every piece of equipment I have be leaking a certain percentage of the voltage. The likelihood of that is probably about the same as me winning the grand prize in the Lottery. Also, even when it was 72 volts with the heater cord plugged in the opposite polarity, you could stick your hand in there and feel nothing. The amperage was 3 ten millionths of an amp. With amperage that low, I almost think something around the tank might be inducing a voltage into it! Could even be something totally unrelated like the heat pump just outside that wall, etc.
Mike

 

[joncat24]

sounds to me like, the first thing I would do is to make sure that you have all your stuff on gfci plugs.
anyone who submerses an electrical device into a container of water without a GFCI is ...in my opinion....just asking for big time trouble. WHo really cares about the copper or anything else. I am talking DEATH.
anyone who says water and electricity dont mix is wrong.....THEY MIX VERY VERY WELL!

 

[stdreb27]

Originally Posted by mikeyfishy
Agreed, but when I unplug things one at a time and see the voltage drop 7-8 volts with each item, I tend to think the problem is elsewhere: not in the equipment. How could every piece of equipment I have be leaking a certain percentage of the voltage. The likelihood of that is probably about the same as me winning the grand prize in the Lottery. Also, even when it was 72 volts with the heater cord plugged in the opposite polarity, you could stick your hand in there and feel nothing. The amperage was 3 ten millionths of an amp. With amperage that low, I almost think something around the tank might be inducing a voltage into it! Could even be something totally unrelated like the heat pump just outside that wall, etc.
Mike
What kind of amp meter do you have and how much did you spend to have one that goes to millions. Most only do 3 decimal places? What do you have it set to as well. I'm not attacking you but I don't think it was measured correctly. Inducing voltage? What do you mean by that? Electricity doesn't just travel through the air. Unless it sparks.

 

[moneyman]

But, 60 Hz alternating current does generate a magnetic field, which can travel through media such as rubber insulator for the pump and wire. And, that magnetic field does create voltage in the salt water.

 

[saltn00b]

you are right, you dont feel it, because the amps are low. amps are what hurt and kill people.
also, fish can live a while with small voltage, they get seriously irritated by it, and can induce bouts with weakened immune systems leading to Ick, etc. eventually it will kill them, so the 6 weeks sounds reasonable.
i would take out the copper ground and get a proper one. asap.
take out any equipment that is contributing to the voltage. if you find something that is an underlying factor, and you can put them back in safely, ok, if not, then replace that stuff. you dont have to be SUPER unlucky and fight crazy odds to have a bunch of crappy equipment, poorly manufactured and spilling voltage. heaters are notorious for it. PH's break down all the time.
make sure everything is connected to GFCI.

 

[threed240]

Its possible to have multi-devices leaking voltage! However multiple devices will add to voltage. If two devices are leaking 20v each, they are both hunting for a ground. So the total voltage at the ground would be 40v. Its the same as hooking up 240v plug. You have two leads of 120v's each, and one nuetral.

 

[mikeyfishy]

Electromagnetism does just travel through the air and can induce a current in something that it is not touching. That's how inductive pickups work on timing lights, that's how some AC power detectors work, and that's how you can get noise/hum from running some cables too close (and parallel) to one another.
My meter has microamps, milliamps, and amps, and yes I know I'm measuring it correctly. The meter is a high end model from Radio Shack. As of a year ago, it was the best one they had. I use them all the time as I have some EE background.
I also have to question the whole theory of how/if stray voltage affects fish. Technically measuring between ground and your water really isn't doing anything constructive because it's all about *potential*. In the fish tank, the fish don't have access to ground so even if you have a voltage potential of 1000v between ground and your water, as long as there is no reference to ground in the water, the fish themselves will be seeing zero volts. Same is true for high tension power cables. You could drop in from a helicopter and sit directly on 40,000 volt lines and feel nothing. Drop a wire to the ground and hold it in one hand and before it even hits the ground you're dead. In fact, I have to question whether it's even a good idea to stick a ground wire in your tank. Depending on where the voltage is coming from, that could be equivalent to providing a ground and providing voltage potential in the tank. Has anyone really thought this through? Seems like all I find is speculation.
Mike

 

[threed240]

I wouldn't think adding a ground in your tank would be a good Idea at all. What your doing is allowing the water to channel this strayvoltage to a ground. This will cause, whatever is leaking the voltage, to get worse. IMO

 

[stdreb27]

Originally Posted by MoneyMan
But, 60 Hz alternating current does generate a magnetic field, which can travel through media such as rubber insulator for the pump and wire. And, that magnetic field does create voltage in the salt water.
And that is why they are shielded. hopefully...
Now lets suppose that there are 72 volts in the system. With .000003 amps in the system, that isn't going to kill fish. That is so miniscule. I'd bet the fish are producing more amps with there beating heart.