Now I need overflow help

[Murminator]

Sighs.....I just have seem to have the best of both worlds The tank is full of water in my garage (for testing if its gonna leak its gonna be there) Its running and I have to either listen to sucking noises or the sound of water splashing. When I put a short return tip on it splashes into the sump making a hell of a noise when I put a longer one on so it is under water thats quiet but then the stand pipe starts sucking. It is a prefab marineland kit similar to this minus the strainer
http://www.all-glass.com/products/aq...megaflow.shtml

any idears???