Flow Question
 

The water in my sump appears to have an oily film on top. This is really noticeable at the bubble brake and return pump compartment. The water on the top does not seem to move. Is this normal.

I had a similar issue on the surface of my sump, if there is so surface agitation a film begins to form. I solved this by adding a powerhead pointed towards the surface to stir the water. You could also probably use some sort of surface skimmer as well. The powerhead is probably the easiest fix.