Ok, Rainman, it looks like this is more complicated than I thought. I have had a couple restarts since my last post. Even with the elbow at the bottom it still won't seem to flow very long. Maybe it's because of atmospheric pressure changes...?
On my first attempt after adding the elbow, it flowed for over 48 hours and looked like it was going to draw all the way down to the inlet. Then overnight it stopped when presumably the pond was almost done draining, judging by how it looked in the evening. But naturally, after it stopped siphoning that night we got torrential rains and the pond was almost full again by morning.
I restarted it and it flowed for almost 24 hours, dropping the pond level about 6 inches. Restarted again yesterday, and as of this morning dropped maybe another 6 inches. Could my fits and starts be the result of atmospheric pressure changes? My outlet is definitely a few feet below the inlet level, but not much more than a few feet.
Thank you all for the great help and info!
Last edited by swampmusic; 03/31/15 08:50 AM.
