72 volts in my tank!!!

[scsinet]

While you may be reading 72 volts in the system when testing from water to ground, it may be any number of things, some of them already mentioned... electromagnetics, induced current between devices, etc.
It's highly unlikely that every device you found is "adding" voltage has catastrophically failed (that is, has leaked water and exposed live parts to the water column). Your current measurements also tend suggest there is no live parts exposed. If there were, you'd be measuring a hell of a lot more than 3 MILLIamps, let alone 3 MICROamps (read: even IF you measured wrong it still is a meaningful measurement).
The 72 volts is not a problem unless the current flowing is enough to cause a problem. The test you did when checking voltage can be deceiving because it doesn't take into account the amount of current flowing in a fault condition. Measurements aside, the course of action I'd suggest is making sure you do what Joncat suggested. Get your stuff on GFIs. That will ensure, when used with a grounding probe, that the GFI will trip if the current levels exceed safe limits.
If the GFIs don't trip, then you should not have a problem. Of course, there is the possibility that a GFI can fail, so you probably want to get one of the small Gardner Bender GFI testers and periodcially test your GFIs to make sure they trip as expected.

 

[92protruck]

Mikeyfishy, I think you maybe overlooking the potential vs. voltage and effects on fish. There are many opinions and mine is that you can't use the "bird on wire" or "dropping from a parachute onto powerlines" example. It's like mixing apples and oranges. I believe fish are effected by voltage differently and there are a few research studies confirming this. The ocean is like a saltwater battery to fish. Many fish have a lateral line organ filled with numerous neuromasts some of which are designed to detect pressure changes as well as electrical charges including changes in electrical fields. There is even a little known fishing method called electrofishing where you stick DC voltage from a battery into the water to attract fish. Too much voltage causes unconsciousness and even death. Obviously, these fish are not grounded but are certainly effected by the voltage. I think an understanding of the lateral line organ and how electromagntic and/or inductive fields effect fish it is a better approach then applying land based electrical engineering. Just my two cents after seeing 50 volts in my tank and running a few tests. I am a big believer in grounding probes.

 

[michaeltx]

if this was my tank I would unplug everything in the tank and slowly turn one thing on at a time and test. I have seen where one thing was leaking voltage into water column and pulling it from other devices like powerheads and pumps.
If you unplud everything and still have a voltage reading then I am at a lose as to where its from.
one thing i will say is that any amount of voltage in a tank can cause problems with fish it may take longer to show when its minute but eventually it will cause problems.
Mike

 

[stdreb27]

Originally Posted by 92ProTruck
Mikeyfishy, I think you maybe overlooking the potential vs. voltage and effects on fish. There are many opinions and mine is that you can't use the "bird on wire" or "dropping from a parachute onto powerlines" example. It's like mixing apples and oranges. I believe fish are effected by voltage differently and there are a few research studies confirming this. The ocean is like a saltwater battery to fish. Many fish have a lateral line organ filled with numerous neuromasts some of which are designed to detect pressure changes as well as electrical charges including changes in electrical fields. There is even a little known fishing method called electrofishing where you stick DC voltage from a battery into the water to attract fish. Too much voltage causes unconsciousness and even death. Obviously, these fish are not grounded but are certainly effected by the voltage. I think an understanding of the lateral line organ and how electromagntic and/or inductive fields effect fish it is a better approach then applying land based electrical engineering. Just my two cents after seeing 50 volts in my tank and running a few tests. I am a big believer in grounding probes.
The lateral line thing is interesting. AC and DC voltage is different. As a east texan and having seen the whole battery thing done. They use a car battery with 500 amps of power. That is a rediculous about of electricity and they are grounded out. Being that the lake is on the ground. My thought is that with .003 amps there is a probablility that the reading is from himself. Not from the tank.

 

[mikeyfishy]

Very interesting, and believable. I know a little about electricity but next to nothing about how it affects fish. For now, I've done the best thing I can do. There's a titanium grounding rod in there and the voltage reads near zero. I've already tried eliminating all the machinery one by one but each one contributes, so there's really nothing I can do. The fish do seem to be doing better though between the grounding pole and the new Eheim 2217 filter.
Thanks for all the info everyone,
Mike
Originally Posted by 92ProTruck
Mikeyfishy, I think you maybe overlooking the potential vs. voltage and effects on fish. There are many opinions and mine is that you can't use the "bird on wire" or "dropping from a parachute onto powerlines" example. It's like mixing apples and oranges. I believe fish are effected by voltage differently and there are a few research studies confirming this. The ocean is like a saltwater battery to fish. Many fish have a lateral line organ filled with numerous neuromasts some of which are designed to detect pressure changes as well as electrical charges including changes in electrical fields. There is even a little known fishing method called electrofishing where you stick DC voltage from a battery into the water to attract fish. Too much voltage causes unconsciousness and even death. Obviously, these fish are not grounded but are certainly effected by the voltage. I think an understanding of the lateral line organ and how electromagntic and/or inductive fields effect fish it is a better approach then applying land based electrical engineering. Just my two cents after seeing 50 volts in my tank and running a few tests. I am a big believer in grounding probes.