A method and apparatus for separating drilling fluid is provided. A housing is provided with a number of vertical parallel spaced apart electrode plates within. The housing is filled with a batch of drilling fluid so that the drilling fluid fills up the spacings between the electrode plates and the drilling mud is subjected to an electro-separation cycle by placing a DC voltage across the electrode plates so that adjacent plates have opposite polarity and an electric field is created in the drilling fluid in the spacings between the electrode plates. During the electro-separation cycle, periodically subjecting the drilling fluid to a vibration cycle by inducing vibrations in the drilling fluid. When the treatment of the drilling fluid is completed, removing an upper layer of fluid from the housing.