I'm telling you man, you can get two 2" bulkheads, with strainers, and two 1" bulkheads, with strainers, shipped (for free) for $56.
Can't beat that that for ease of use and not having to figure out how to work a pvc overflow over the edge of the pond, through the floor of the enclosure, and secure it enough that a full grown caiman won't knock it loose. Plus you won't have to worry about restarting the siphon when you turn the pump off. It will automatically start!