A standard siphon with an air vent pipe on top will do both. It can be used to siphon if the air vent is closed with a cap or it can keep the water level at a set height just like Kelly drew. We use several types and they all work. You can go to Pond Dam Piping's web site and see a bunch of them.

See this http://www.ponddampiping.com/syphon1.html

Last edited by ewest; 12/22/11 11:02 PM.