In this paper, a phage filter has been developed to capture, concentrate and isolate small numbers of pathogens from large volumes of water. The phage filter consists of a magnetized filter frame and hundreds of phage-coated filter elements made of a magnetostrictive material. ANSYS Maxwell magnetostatic simulations have been conducted on filter designs. A prototype filter frame in the size of 2″ has been made of a PMMA pipe and Permalloy 80 wire. Two permanent magnets were used to generate a uniform magnitude of magnetic flux density and a desired direction of flux vectors to align and hold a high density of filter elements. The filter elements in the size of 4 mm × 0.8 mm × 30 µm were made of Metglas 2826MB ribbon by mechanically dicing. The experimental results were compared with the simulation models to improve the filter design.