Surface Skimming

[Rlon35]

I get this film on the top of my planted tanks, soemtimes It doesn't go away with water changes. Fluval has an attachement that will skim the surface of organic matter. Are there any advantages and diadvantages, in your opinion about doing this in the planted freshwater tank??? I can't seem to get to a page wherein I can see how the Fluval Skimmer Attachment works, but I thought I'd try for some feedback here.

 

[RadaR]

They can be used. Generally if you don't overfeed the fish, supply the plants with everything they want and provide some surface movement then you can prevent it. After all, we don't want the surface to be still. We want some water movement, not enough to "break" the waters surface but just enough movement to provide good gas exchange.
Too much drives off CO2.
The skimmers are fine though. James uses one on his tank.
With using one, you may find that you just have to turn the CO2 up a bit extra.