Does anyone have a DIY PVC overflow that they like? Does anyone have a link to a restarting over the back overflow design. I have been trying a few out and haven't had a lot of luck. I need one that can sit dormant for several weeks before it is needed. The goal is to have it as an emergency overflow on a very large kreisel. Occasionally the normal overflow screens get clogged with very large jellyfish and the tank (very slowly) fills up and overflows. I have used a few designs that "restart" after a very brief siphon break but none that restart 2 weeks later.