height

I have a durso pipe that I made for my Peninsula Aquarium and I think the bend in it needs to be lower maybe I need to cut the pipe down a few inches because I'm having to restrict the flow quite a bit and I have a good size return pump would lowering the pipe help at all?

This is one of four siphon drains. There will also be four backup drains. Is this the appropriate height for the siphons?