No film but dust yes. A brown powdery dust. The flow on them is good. I blew it all off of them earlier today with a monoject and will watch to see if it comes back. If it does I have a dip coming this week hopefully if the mail is fast enough. I can always go to my farm and grab some peroxide and dip them in that at the right dilution.The dust or film you mentioned makes me think bacterial or lack of flow