flatlander using 3\16?

[asknupp]

Living in west central Ohio its hard to find enough slope at the end of any runs to make 3\16 vacuum available. ? is would I be better of staying with 5/16 or going with 3/16? Its all on gravity set up mostly in small acre block woods with mature trees that would have two taps per tree. Most lines would average 10- 20 taps getting out to collection barrels at fields edge. Any advice would be greatly appreciated.

[maple flats]

The advantage of 3/16 is that it fills easily and then gravity can pull. If you don't have the drop in elevation, I think you are better off with 5/16.