Quote Originally Posted by blissville maples View Post
This pump has never been used anywhere else, first time hooked up it was at 27.5, found some leaks now at 28.5
I re-read it, I didn't pick up on the 3/16ths only being part of the entire system.

So, you were experiencing low 18 inches on an existing 5/16ths section, switched it to 3/16ths and experienced the same mediocre results. Started switching it back to 5/16ths and now experiencing better results? That leads me to ask why the original 5/16ths was not producing those better results in the first place?

In all reality, I am not sure why 3/16ths is being introduced into mechanical vac systems. Wasn't it developed for its great natural vac properties with the right slope conditions? And wouldn't mechanical vac negate any natural vac that might be created with slope? I realize when there is no sap flow, there is no vac with natural flow, and with a pump there is all the time. For someone like me that has no interest in adding a mechanical vac system, it is great getting 27+ inches during the runs.