Slimy film on top of water

Question
I see a slimy kinda oily substance on the top of my water. It seemed to apear when I changed the filter pads. Do you know what it is, how to prevent and clear it up. I just did a water change and ran my Diatom filter for a day and a half to clear up slightly green water. Thank you

Answer
Hi Allison,
Thank you for your letter. My system is holistic, based on preventing water pollution. Check my page to see if you think you could be over feeding. If so, buy a bottle of Cycle and follow the emergency care instructions at the bottom of the page. Please read & print for future reference:
http://steamboats.com/aquarium.html
I hope this helps. Write back if you want to discuss further.
Nori