diy durso pipe for overflow

[sergifed91]

i have been considering redoing my durso overflow pipes to my marineland corner overflow on the 125 gallon reef ready tank. I have one side that will work great but the other side will not siphon the water at all. I have to play around with the durso to get it to start draining. i can add pictures later on after work. i have looked for clogs, took it apart and cleaned it. but no matter what I do it will not start draining without messing with it until it starts to drain. any recomendations orpics of overflows for a new overflow design for the pipes.

 

[sergifed91]

i modeled the durso pipes the same way my marineland 75 gallon looked like. so I know it's right the only thing I can think of theres an air bubble and the water doesn't want to drain because of it.