hey guys i have got a vertex In-100 in sump skimmer. I have been very happy over the past year with the output of it until now. It seems like there are less microbubbles and it hasn't produced a frothy skim over the past couple of weeks, only larger bubbles at the top of the water line and less junk comming out of the water than before. My question, is this due to a pump going bad or something else. Everything seems the same with it, no loud noises and is still running good just no froth anymore to take the bad stuff over the edge to the cup. There for my skimmer is not skimming ?????