new over flow not working.

[reefcrazy]

ok i bought a over flow at lfs and when i got home it didn't have instructions. i called lfs and they told me it was rated at 500gph. i bought a mag7 that pumps water up 4 1/2 feet up, that would be like 450 gph. i get the pump going but over doesn't work. any suggestions also the u tube on my over flow is 1in.

 

[mr . salty]

To start an overflow you must fill the outside box with water,then feed a 1/4 inch air hose into the U-tube till it reaches the top.Then suck the air out of the U-tube.This fills the tube with water...Then you should be able to start up the pump and the overflow should work...