I have a 4 pot autopots watering system and I plan to only run tap water through it. It looks like the autopots people recommend that you put a valve at the end of the line. It looks like it is to flush the line every once in a while to clean the tubes out. I would think that would be for those that use salt based liquid nutrients. If you are only running tap water in the reservoir do you think you would need the valve at the end of the line. Do any of you use autopots and not put the valve at the end of the line for it on there?