Stray Voltage

[mike31154]

Voltage measured with a meter from a tank to ground is not necessarily an issue. It's when the voltage has a path to ground. This will result in current flow from the voltage source to ground. If something of lower resistance gets between the voltage & ground, that results in shock. Generally, if the electrics running your tank are plugged into a GFCI outlet, you'll be safe. While 30 volts is getting up there, there are many pitfalls when trying to measure voltage & current in salt water. If you're not getting zapped when touching the water & the livestock isn't acting weird, there shouldn't be cause for concern.