New spiral wound element improvements have been made so that RO/NF products are more robust. One improvement is the design of vents in the seal carrier or ATD's on the ends of the elements. This feature has proven to quickly equalize the pressure on the inside of and outside of the element and prevent rupture of the FRP shell. A second improvement is the development of feed spacers which have lower pressure drop. Thicker spacers with a unique geometry have been shown to have less pressure drop and reduce the frequency of chemical cleaning when treating water of poor feed quality.