Abstract: A two-stage filter enclosed within a single vessel is provided. The two-stage filter is provided in the form of the vessel having a first filtration stage configured to capture particles of a first size, and a second filtration stage downstream of the first filtration stage and in fluid communication with the first filtration stage configured to capture particles of a second size, wherein the first size is larger than the second size. The first filtration stage may comprise a porous media. The second filtration stage may comprise one or more membrane filters.

Abstract: Some embodiments provide a pool filtration system for filtering pool water including a pump, a primary filter in fluid communication with the pump, and an auxiliary filter in fluid communication with the pump and the primary filter. The auxiliary filter can include a membrane filtration module, and a flow distribution manifold. The flow distribution manifold can include an influent port in fluid communication with an influent flow opening and an effluent port in fluid communication with an effluent flow opening. The influent flow opening and the effluent flow opening can be fluidly coupled across the membrane filtration module. The flow distribution manifold can further include a bypass mechanism. The bypass mechanism can include at least one valve that selectively fluidly couples the influent port to the effluent port to bypass the membrane filtration module.