Floating debris?

[dingusplease]

I'm still cycling my 3 gal picotope, but there's this layer (more like a film) of dust/debris/oily matter that won't go away. I did a 5% water change, but it didn't help. What can I do to get rid of it? I know water changes are the better option for a tank this size, but could a small airstone skimmer help with this problem? Here are some pics of the setup, with one powerhead on the middle right side, and one on the right-back area.







One possibility might be that my LFS rock isn't fully cured. Here is one pic of the section that raises my suspicion:

 

[Rare]

More surface agitation @ least with bigger aquarium is what helps or overflow system. On that small foot print I really dont know but maybe point the powerhead if that is what you have in there up more

 

[Sniperhank]

A skim on the water's surface is a reflection of poor surface agitation, like stated above. It is a collection of the excess protein/nutrients in your water that is normally removed by mechanical means, such as protein skimming.
I would highly suggest against something like an airstone. These break the surface and will begin to cause unneeded salt creep.

 

[dingusplease]

Thanks guys for the help. I moved one powerhead closer to the surface and the film is already disappearing! Really appreciate it!