Abstract: An improved electrolytic system for treating aqueous solution which passes the solution along an inner helical insulator wrapped around a centrally located anode solid rod and an enclosing inner cathode tube, then along a cathode tube wrapped or spaced with another helical insulator and an enclosing outer anode tube. The solid rod can be replaced with an innermost tube in order for the solution to initially pass through a cathode portion of the system. Also, the innermost cathode tube can have a plurality of apertures as passageways for the solution. A DC voltage is applied, in one direction or in sequential fields of different directions across the plurality of metal rods and tubes, thereby effectively removing both suspended materials and dissolved solids from the aqueous solution to be treated. The power supply required from the DC voltage can be decreased by treating specified tubes or rods.