I find surface skimmers (Eheim 35) to be very handy. Although I never get surface film, I find the skimmer pulls in dust that lands on the water surface. Once I tried without the skimmer and I landed with fine dust floating in the tank.
I also turn it on after trimming carpet plants. It simply pulls in all the tiny leaves floating and after 1/2 hour, I just clean the skimmer.
I also turn it on after trimming carpet plants. It simply pulls in all the tiny leaves floating and after 1/2 hour, I just clean the skimmer.