Electroosmotic dewatering was enhanced by periodically interrupting the power (the off-time) and simultaneously short circuiting the electrodes. Noting that continuous application of power corresponds to an off-time of zero, the final amount of water removed increases with off-time, goes through a maximum and then decreases. For Hydrocol clay, the experimental optimum off-time was 0.1 s for an on-time of 30s.