hi i am trying to set up a van mount system, ive bought all the items i think i need :-Tank, frame,pump,flow master, 20"pre filters 40/40 RO,11L di vessel,auto fill. I understand the water comes through the auto fill and pre filters then to the RO and di vessel. I have not yet got my head around the inlet, outlet, and drain connections of the RO and how to control the amount of waste water from it. Ive got the stainless steel type housing which has a center connection at each end and a connection off center at each end . I would be extremely greatfull if anyone has ideas on how to plumb the 40/40 RO