This compact, sophisticated filter unit combines the function of two filter units; a Dual Vessel Bag Filter Unit with a Dual Vessel Cartridge Filter Unit. The unit allows pre-filtration and polish filter with bags or cartridges, within one unit. During the cartridge operation, the baskets and basket plate can be stored in a special storage rack in the unit. The Dual Vessel Cartridge/Bag Unit has the capability to use standard filter bags as well as standard plug-in cartridges.