I just replaced my protein skimmer in my sump. The return for it causes my sump to fill up with bubbles and make my tank look like crap. We use these skimmers in our store and they dont do it there. This is a skimmer that is custom made by a guy in California. I'm just wondering how to eliminate all the bubbles that are being returned into my sump. It has a vertical return so it just kind of spills over back into the tank. There is a sponge surrounding the return tube but that doesnt stop the bubbles.