Inspired by http://www.aquaticquotient.com/forum...urface-Skimmer, I did a DIY for my 1.5ft as I was having some unsightly "oil" too.
I used a S$6.50 Aqua Zonic Emperor Mini and cough syrup bottle.

Step 1:
DSC_0160_zps636d4455.jpg

Step 2:
DSC_0161_zpsa2a4ca83.jpg

Step 3:
DSC_0162_zps78e3d372.jpg

In 30mins my tank is crystal clear.

Cheers.