I am running a Reef Dynamics (don't know which one) skimmer and a Sedra ksp-5000 pump on it. In the last few months it has been making a louder and louder gurgling sound out of the air intake and I can't figure out how to stop it. I have tried running water through the line, putting vacuum on it, etc but can't get it to stop gurgling. Any idea what is up? It is getting pretty annoying.

