Loud Sucking Sound

[Snufflupagus]

Hello all,

Well I finally filled my tank today to test for leaks and make sure the plumbing didn't leak...Everything is great, except on thing. In my over flow, when the water is going into the pipes and down to my sump, it's making a loud sucking noise. Does anyone know how to fix this problem? I'm not sure if it's just that my pipe is to close to the water level and is producing little tornados in which air gets in the pipe, or if there is something else that could be wrong. Any help would be appreciated.
THanks, Colin