In an aluminum pot line including plural electrolytic pots for production of aluminum metal arranged in end-to-end relationship in at least two rows and provided with electricity by plural parallel conductor bus bars arranged longitudinally of the pots, an independent bus bar at the rear of each row of pots for degaussing the magnetic field created by the electricity carried by the conductor bus bars of the opposite row of pots. The degaussing bus bar is located in substantially the same horizontal plane as the conductor bus bars and carries up to about 25 percent of the current of the latter, but in an opposing direction. The electric current of the degaussing bus bar may be subsequently cycled into the conductor bus bars.