Tanks containing up to two cubic feet of ion exchanger products or filter media which are rented to homeowners or business clients with the beds fully-regenerated and ready for use. Portable exchange tanks do not have the valve controls required for regeneration. Upon exhaustion (determined by predetermined calendar days, meter, or monitoring device), the tanks are returned to a central regeneration plant where the resin or other media in each tank is reprocessed and restored for reuse. Portable exchange tanks may be available with water softening or deionization resins, mixed ion exchange media, manganese zeolite, activated alumina, and activated carbon. Portable exchange tanks are used for both household and commercial applications.