Abstract: A filtering device including (a) at least one surface filter element, each including: (i) first and second faces, the second face disposed substantially opposite to the first face, the faces having a first outer contour; (ii) a first opening through the faces, forming a first inner contour of the faces; (iii) a large plurality of grooves disposed on the faces, the grooves connecting between the outer and inner contour, the grooves adapted to trap solid particles; (b) at least one liquid-permeable filter element, each including: (i) third and fourth faces, the fourth face disposed substantially opposite to the third face, the third and fourth faces having a second outer contour; (ii) a second opening through the third and fourth faces, forming a second inner contour of the third and fourth faces, wherein the outer contour of the liquid-permeable element is larger than the outer contour of the surface element, and the third face of the liquid-permeable element is associated with the second face of the surface e