I use rubbermaid container for my water storage. I have a 50 gallon containor for fresh water from the RO/DI unit and then I mix saltwater in a 31 gallon container. Never had any film build up in the freshwater, but have noticed a white film if I let saltwater sit in the container too long without circulation. I don't think it is a problem. I think the guy on Reef Central just grabbed a trash can real quick before he had to go out of town and maybe forgot to rinse it very well or the water just sat too long. Most people are now spending the extra money for "food grade" containers. If you don't clean these out occassionally and if you don't circulate the water, you still end up with the same problem.