Overflow Problems

[1bigstud]

Due to Lack of patience and experience when I first got my tank I didnt bother to get it drilled and used an overflow box. MY overflow u tube is gravity powered. I have recently upgraded my setup, in my old setup I had my return pump at such a level that wouldnt allow flooding of my tank in case the u tube lost it's siphon unfortunatley my new setup does not allow this. Is there any way I can hook up a power head to my u tube to suck out air and prevent a siphon loss? or to be able to recover on it's own in a power outage?