Hi, As I'm new on that forum and partly in that business forgive me please, if a question I'm going to ask is too obvious. I'll get tank, planning to set up system (buy one) for purified water and to be honest I'm little lost about next step: I know need a pomp with controller, need RO or DI or both but what's about membranes sizes etc.? Tank, I'm planning to use will be up to 600l, everything on my pick up, does this one would work http://www.windowcleaningwarehouse.co.uk/FRO20.html of course excluding pomps and controllers? Simply, I'm looking for bestspoke system I could install easily on my pick up and just start it. Thanks for Your help!