Keep an eye on the fins, let me know of any changes... and if you could take a picture of him if it gets any worse, I would be able to judge a little better what's going on.

I think I know of the film you are talking about. My firebellied newt's tank gets like a white film on it. My best guess is to keep the tank covered. I think a full hood would do the trick nicely without messing with the dissolved oxygen (the surface water gets oxygen through diffusion from the atomosphere).
-----
Phishie
Site Coordinator

"An ounce of prevention is worth a pound of cure."