Hey hey!
Well this particular post is a little dated. Since the run was assembled, I have build a water reservior. It's an insulated 5-gallon-bucket stand with walls that feeds 1/2" PVC with several self-filling watering cups.
A light duty spring pushed an empty cup up, opening the valve, it fills with water, weighting the cup down and closing the valve. Great system, gravity fed, and no leaks. And there a pvc union to remove the 5 gallon bucket from within the stand for cleaning.
View attachment 3613379
Lasts about a week in the plain of summer. Cups are easy to clean with a toilet bowl cleaner. Turn them (threaded) to dump and back to refill.
View attachment 3613377View attachment 3613378 I plan to insulate the pipes before the winter.