I swear by surface skimmers. I used to use one on my old 55 on the intake for my canister. You can pick them up on Amazon for 10-15 bucks. Just be careful not to get any sand in them or the plastic screw adjuster will freeze up. They clear up the surface film in no time. Another thing to use is a sponge filter, cheap and can be moved to a QT/hospital tank if needed as well.