In one embodiment according to the invention, there is provided a filter device for liquid filtration, the filter device being in fluid communication with a plurality of liquid pathways, at least one pathway of the plurality of liquid pathways having a smallest equivalent fluid flow diameter of the plurality of liquid pathways. The device comprises a filter membrane (108) and a filter core (109) comprising at least one cross hole (110) in fluid communication with the filter membrane, each cross hole having an equivalent fluid flow, diameter. The sum of the equivalent fluid flow diameters of the at least one cross holes does not exceed the smallest equivalent fluid flow diameter of the plurality of liquid pathways.