Abstract: A filtration apparatus is provided which is easily convertible to a bag, sleeve and disc, cartridge, or tube filter configuration. Additionally, the apparatus is adaptable to function as an ion exchange column. The apparatus includes a tank having a base with liquid and gas inlets. A removable cover also has liquid and gas inlets and an adapter onto which several different filter elements may be coupled including a bag filter, a disc and sleeve filter, a cartridge filter, a tube-type filter, and a strainer for when the apparatus is to be used as an ion exchange column. The tank is capable of having liquid flow through in either direction and can be pressurized or evacuated as needed.