Film on top of water.

I had the film problem myself. The only way to get rid of it is to REALLY get the surface of the water nice and agitated. It won't go away instantly. It took me a few days to a week but not whenver I shut all of my pumps down the surface of the water is perfectly clean. Also, do you have something that is skimming the surface? An overflow box of some sort? If the water level is too high it won't work properly. The water should flow into the overflow and down - not just the same water level. This would happen possibly if the drain is partially clogged.