I have disengaged it completely from the sump. The 3/4 inch discharge dumps into 2" line, which temporarily flows into a gutter and into the yard. Garden hose fills the IBC for now. So there's plenty of air to break the siphon where it dumps into the 2" line. The purpose of the air gap here is to function as a gas exchanger.
What is Photobucket?
A pic to show how each barrel works, from the flow in, to the flow out. Each one of the 6 is identical.
This pic shows the water level when the siphon stops. It's not supposed to stop for at least another 1-2 inches lower. EVERY barrel half stops at this point.
Picture of all 6 beds with 3/4" fill lines and ball valves. Volume tank and sump barrel are behind me when I took the picture.
This shows the general concept of how it all works.