Ok I just opened my filter, this is one of those that sits outside the tank, and ontop of the water next to the bio fiber i noticed what lookes like very light white film. It is not moving with the water more like it is floarting on the top. Which i thought was funny because it is just a few cenemiters away from where the water falls backinto the tank. Yet it does not move with the water. Could this be Good bacteria? I have no idea what it is and i can not take a picture, as it does not appear in it well. Any ideas? Is it not suposed to be there?