Wiring advice/help needed (voltage in tank)

[Wildechild_01]

Originally Posted by Vancity

With everything unplugged i get 2.7 volts (this is literally with NOTHING in the tank plugged into a power source)
with the lights plugged in it goes up to 4.5v
+ skimmer 21.6v
+ heater 32.4v
+ koralia powerhead 40.8v
+ aquaclear filter 54.0v
+ rid-volt and it drops to 4.0v

This is actually a very complex situation. I will assume that your GFCI is installed correctly as they are fairly straight forward. What you are dealing with is what we call Induced Voltage. Everything electrical generates an electro magnetic field. When this field interacts with something that conducts electricity (like salt water) a voltage is created. The Ballast in your light fixture, and the fluorescent lamps themselves cause this, as do all of the motors in your tank. Skimmer, powerhead, filter.. and even the power flowing through the heater all act to create a voltage in the tank. This does not cause the GFCI to trip because there is no loss of power by any of the items plugged in. The voltages you read are electrical potential differences between the water and your homes ground, providing that is where your other meter lead is. The 2v you read with nothing plugged in could be from any other nearby electrical device or could just be residual not quickly dissipated when you unplug everything, or other things.

As the tank sits without rid volt, there is a potential in the tank but with nowhere to flow there is no current flowing and no real risk to your tank inhabitants. You being shocked is another matter, when you touch the tank you become that path for electricity to flow, something as simple as wearing shoes while working in tank can actually eliminate this. Adding the rid-volt will give the voltages induced somewhere to go meaning you shouldn't get shocked, it does mean however that now your tank inhabitants constantly have electrical current running through their habitat.

Tricky decision. The 50v is not likely to cause any real harm to you, but if your standing bare foot on a metal drain in a puddle of water the potential is there, i generally only notice it if i have a small cut on the finger in the tank, and I'm touching the stand

As a read back through this i realize it may be more confusing than helpful. Short story I guess, unfortunately there is likely nothing you can do short of disconnecting everything electrical anywhere near your tank and then stirring the tank with a wooden spoon for flow and the sun for light. But I wouldn't stress out about it too much. If your worried about the zap put the rid volt in just keep an eye on your fish to see if it seems to affect them.

Hope that helps a bit, if not let me know and i will try again