oil

So i started cycling my tank last monday, all seemed to be going well until this morning when i looked at the surface water which seems to have an oily layer in it.   Im not sure if this has been caused by a recent "spring cleaning" in the living rom where the tank is or something else...

Surface skin has got worse, I tried the newspaper method, and it didn't really work, I don't want to airate as I am doing DIY CO2. I even tried cutting up some polypropylene sheet but it didn't stick to that. I have filter papers, do you think lining a net with filter paper and lodging it...