sl305, I have not had much luck with the fission skimmer either, but I have read where others had.
In my experience so far (just 4 weeks), the bubble pad ends up getting filled with the skimate instead of the cup. Also, the bubbles are out of control in the display part of the tank. I am going to experiment more of course and see if I can't get it to work better. If so, I'll let you know. If you find a solution before me, drop me PM because I am also interested.