Ok guys, well I went ahead today and purchased some plumbing parts.
I built a bell siphon which seems to work pretty good. Although once in a while it gets stuck in this weird pump-siphon loop where the siphon just doesn't seem to break. I think it happens when the clay pebbles get stuck in in the holes. I'm going to build some kind of mesh thing around it so that can't happen anymore.
I'm going to attach two files.