Hi I built a single 4x40 membrane RO system with a 240 Procon pump a few years ago and it works great. Now I am looking to improve my system to allow me to run it less hours. I am wondering what you guys would recommend adding a 2nd membrane, adding a re-circulation pump, or larger Procon pump? I am worried if I add a 2nd membrane that it will foul quicker without adding more flow.