The invention provides for a slider for a leak proof slider-zipper assembly having a leading edge and a trailing edge comprising a pair of protrusions at the bottom of the leading edge, a pair of protrusions at the bottom of the trailing edge, and an opening plow protruding from the top surface of the slider, between the leading edge and trailing edge, and having height not more than the height of the slider. The opening plow has a sloping surface from the leading edge towards the trailing edge such that the height of the opening plow at the leading edge is less than the height of the opening plow at the trailing edge.