This is an explanation of how a traditional bell siphon operates. It goes into some of the physics of how the auto siphon gets started and stops. One of the biggest problems I've run into is getting them to stop properly on large grow beds. I've solved this problem with one simple little piece! It's so simple, I'm kicking myself for not figuring it out years ago!
This grow bed is using 3/4" pipe for the drain and standpipe with a 2" bell. The fill rate is LESS than 1/2 liter per minute and the siphon still starts with no problem. It's been running for about a week without any problems.