A fluid treatment apparatus for treating a fluid comprises an electrochemical cell having fluid orifices to receive and release fluid, and a fluid passageway connecting the orifices with a water-splitting ion exchange membrane is exposed to the fluid in the passageway. First and second electrodes are positioned about the membrane. The apparatus also comprises a controller to control and operate a power supply and valve system. The power supply supplies a current to the first and second electrodes at sufficiently high current density to result in bacteriostasis, deactivation, or a reduction in the microorganisms in the fluid. The controller can also operate a set of cells to deionize fluid and regenerate the cells.