Wrong. A siphon is only a siphon when the air vent gets closed off by the high water level in the pond. Until this happens, as you say, the water will just trickle through the pipe when the level is at normal pool. But when the water gets high enough to close the air vent, watch out because a siphon can flow almost 5 times as much water through the pipe as gravity can. Once the siphon lowers the water and uncovers the vent, it goes back to a gravity feed again.

Hey Moe, I'm trying to think but nuthin's happening!