The Lifereef overflow is the most reliable overflow on the market. The siphon does not break. To start it, be sure the front and back are both full of water. Put a piece of airline in the U Tube so that the end is at the top of the U. Put the U Tube in the overflow. The rear side goes in the section without the drain fitting. Suck the air out of the U Tube. There will be a little left at the top, but thats OK. Remove the airline. When you start the pump, the air that is left will be pushed through. As long as you have adequate flow through the overflow (200 GPH+), all bubbles will be carried through the U Tube.
