Abstract: An electrolysis cell comprises a housing receiving a plurality of parallel electrodes separated by guides to define a plurality of passageways through which an electrolyte solution is flowed from an inlet end to an outlet end, the solution being subjected to electrolysis by applying an electrical potential between electrodes. At the inlet and outlet ends, spaced wall means engage with the electrodes to extend the electrolyte passageways and confine electrolyte to the respective passageways whereby a short circuit through the electrolyte between electrodes is avoided.