I have an eshops x-120 on my 60 gallon cube. It was working great then I did a water change. Now when the water keeps coming out of the top. I have played with the air flow and the amount of water coming out of the skimmer. Nothing has worked and its driving me crazy because its been doing it for about 2 weeks now. I tried letting it just run and hoped it would fix its self but bubbles are going through the return and into the tank which I am sure stresses the fish out. Any help would greatly be appreciated.