Your thoughts on stray voltage please

Nicky,

You may wish to do a search on "grounding" here. I seem to recall reading that it is not a good idea to ground (or earth) a tank as doing so will make it possible for the fish to be electrocuted. Dats just what I remember, could be wrong

Roan

In the exact situation you mentioned - and this is important - stray voltage from electro-magnetic fields and NOT faulty equipment you dont need to worry at all.
Voltage isnt dangerous to the fish - the fish in the water cant tell what potential level their tank is on (voltage = potential difference). Its only dangerous if there is a current flow - which would only happen when faulty equipment comes into play.

After having shocked myself from a problem component, all of my tanks are grounded and have been for years. The leak apparently was not enough to trip the GFCI, but I could feel it. No more, NIMT.

There are few things I do not agree with RTR on, But I don't see a need for grounding the tank. I certainly would agree that it cannot hurt to do so. GFCI's were designed for the protection of humans, and should trip before any real harm is done. Different people are more or less sensative to electrical shock, so it is possible to feel a shock at a level below that which would trip a GFCI. I don't feel much after years of zapping myself, so I probably wouldn't know if a piece of equipment was faulty before it tripped a GFCI. If you create enough of a ground to be a problem the GFCI should kick out in every case.

Either way as said in the other thread, I would not use bare copper wire in a tank. This may be an unecessary precaution, but I don't like copper.

Dave

I may well be a hot house flower, but I will never put my hands in a tank when I feel a tingle. No thank you. Titanium grounding probes are cheap, and I am neither stoical nor masochistic.

couple of things I can think of
first in order to hurt the fish, current would have to flow through them - example: birds perch on live wires all the time, no ill effects unless they happen to come in contact with ground while touching the wire, then poof

by grounding the tank you may actually be increasing the likelyhood of current flow through the water and therefore fish.

electro chemical reactions take place when current is allowed to flow through water. Lets say you have a motor that is not properly insulated, most likely its windings/conductors will be made from copper. If you ground the tank with a metal conductor, one of the conductors (the softer one) will give up metal oxide to the other. One becomes the anode, one becomes the cathode and the water becomes the electrolite. In the marine environment boats have a chunck of zinc (called a sacraficial anode) bolted to the hull to protect other metals on the vessel.

last thing I can think of is that we regularily "shock" rivers and streams around here to count fish. The equipment used produces very high voltage (20,000-30,000volts) to product a tiny current flow through the water. The fish are stunned long enough to identify species and count, pehaps even collect scale and DNA samples. The point is that at 120volts your not going to hurt the fish but you may kill yourself if you happen to be also touching ground.

don't know about the affects of prolonged metal oxides, but I suspect it can't be good for the fish.

Bottom line is if you feel a tingle of any kind, don't worry about the fish worry about yourself and get it fixed.