Film on top of tank

Question
I have a 45 gal. saltwater tank.  I have an Eheim cannister filter and a protein skimmer on the tank.  Occasionally it gets a film on top.  What can I do to get rid of it and how do I prevent it?
Thanks.  Deane

Answer
Hi Deane

The film sounds like mixed organics and oils.  The best way to get rid of it is to provide lots of surface agitation by using powerheads.  I would recommend TUNZE Nanostream series of Hydor Koralia for extra flow.

Also, if you installed a sump and overflow, this would also get rid of surface organics.  

I also recommend getting rid of the canister filter your tank.  They are not required for marine tanks.  Live rock will provide the filtration and a protein skimmer will get rid of nutrients in the water column.

Kind Regards

Michael