i dont even use these type but i was wondering is there a trick to starting an over flow. i have a couple laying around and i tried to set them up but had no luck.
prime it, duh. lol put a little piece of airline tubing in the u-tube and make sure there is water below both ends of it and just suck the air out of the u-tube and wallah!
you can stop hitting yourself... unless someone got lucky and saw how to do it.. the first time ALL of us set up overflows we asked the same thing (though some of us used the search feature so no one found out)