A device for separating ions from a fluid stream is disclosed. The device includes multiple chambers in fluid communication with one another. A first chamber has an inlet, and a last chamber has an outlet. The inlets and outlets of intermediate chambers are connected to one another so that fluid flows in a circular pattern through each chamber. A magnetic field extends through the chambers perpendicular to the flow. The magnetic field induces a force on the ions, moving ions of one polarity to ward the center of the chambers and ions of the opposite polarity toward the periphery of the chambers. Each chamber has an outlet for drawing fluid from the chamber center. The circulation direction reverses in each chamber allowing both positive and negative ions to exit via the outlets. Fluid of reduced ion concentration exits the outlet channel.