Abstract: A filtration systems for fluids, particularly biological fluids. The filtration system includes a filter containing compartment connected at one end to a storage vessel and at the other end to a diaphragm pump. The filter comprises a hollow fiber module or a screen filter. The vessel serves as a storage container for a process stream to be filtered. The diaphragm pump provides the means for generating rapid, alternating, low shear tangential flow between the vessel and pump and through the hollow fibers or screen filter. The system allows easy removal of wastes from the fluid and the addition of fresh fluid to replenish the filtered fluid.