A manifold plate comprising: a body having an exterior and a length, width, and thickness extending along x, y, and z directions, respectively, of a standard x, y, z coordinate system, wherein the exterior of the body includes an outwardly facing mounting region against which one or more fluid treatment units can be mounted, the mounting region generally lying in an x, y plane of the body, wherein the mounting region includes a plurality of first openings and a plurality of second openings arranged to fluidly communicate with fluid treatment units that can be mounted to the body, the first and second openings (30, 31) being fluidly isolated from one another; first and second fluid channels (32, 33) extending along the body spaced from the mounting region, wherein the first and second fluid channels (32, 33) are 7.5 cm (3 inch) or less apart and fluidly isolated from one another and wherein each fluid channel (32, 33) includes a port which opens onto the exterior of the body away from the mounting region; and a plurality of first passageways each extending from and fluidly connecting one of the first openings to the first channel and a plurality of second passageways each extending from and fluidly connecting one of the second openings to the second channel, wherein each passageway (40, 41) is defined by a wall and at least a portion of the wall extends at an angle less than 90° to the mounting region and wherein a projection parallel to the z direction from every point on the wall of each passageway (40, 41) intersects the corresponding opening (30, 31) in the mounting region without passing through the wall, and wherein the first openings are aligned with the second openings. a body having an exterior and a length, width, and thickness extending along x, y, and z directions, respectively, of a standard x, y, z coordinate system, wherein the exterior of the body includes an outwardly facing mounting region against which one or more fluid treatment units can be mounted, the mounting region generally lying in an x, y plane of the body, wherein the mounting region includes a plurality of first openings and a plurality of second openings arranged to fluidly communicate with fluid treatment units that can be mounted to the body, the first and second openings (30, 31) being fluidly isolated from one another; first and second fluid channels (32, 33) extending along the body spaced from the mounting region, wherein the first and second fluid channels (32, 33) are 7.5 cm (3 inch) or less apart and fluidly isolated from one another and wherein each fluid channel (32, 33) includes a port which opens onto the exterior of the body away from the mounting region; and a plurality of first passageways each extending from and fluidly connecting one of the first openings to the first channel and a plurality of second passageways each extending from and fluidly connecting one of the second openings to the second channel, wherein each passageway (40, 41) is defined by a wall and at least a portion of the wall extends at an angle less than 90° to the mounting region and wherein a projection parallel to the z direction from every point on the wall of each passageway (40, 41) intersects the corresponding opening (30, 31) in the mounting region without passing through the wall, and wherein the first openings are aligned with the second openings.