Abstract: A filtration system for a cross-flow membrane filter which reduces the deleterious effects of concentration polarization and membrane fouling, thereby increasing the average transmembrane flux. The filtration system includes a feed supply for providing a feed solution; a feed pump connected to the feed supply; a cross-flow membrane filter connected downstream of the feed pump for separating the feed into a permeate and a retentate, the cross-flow membrane filter including at least two membrane ports and at least two permeate outlets; a valve manifold assembly located between the feed pump and the cross-flow membrane filter; and a control system for controlling the valve manifold to selectively reverse the flow of the feed through the cross-flow membrane filter.