Oily Water?
 

Not sure exactly what is wrong or if there is anything wrong but there is an oily substance that floats on the top of the tank. Not a whole lot but it its noticeable when feeding and cleaning. Does anyone know what it is and if its bad.
Have a 55 gal tank, topfin 60 filter, 5 convict cichlids, 1 salefin pleco, and these two little crabs bought at the lfs.
thanks for any help you can give.

I get the same oily film at the top of my water if there's isn't enough water disturbance - especially after feeding. Can you change the angle/setting of your filter so that the flow is breaking the surface?

It seems to a common thing to happen once in a while. The only thing I know of that causes it is a protein that floats on the surface.

The best way to remove a majority of it is to float plain, uncolored and unscented paper towels on the surface to absorb it. Simply place the paper on the surface and remove it immediately.

I also have this oily film in my tanks. I first had it in one of my tank and then noticed it in the others too. I thought it was some bacteria and was going to post a question about it. Now thanks to this thread I realise that it may not be so bad and can be cleaned up easily. Thank you all! :D

Some foods will cause it. I have gotten it especially when I do not peel zucchini even after washing it really well.

Water changes can often help to control the oil slicks. When I neglect my tank it can take a couple weeks of regular water changes to finally get rid of it.

thanks for the input, i do regular 15% water changes once a week, and have three other tanks none of them have the problem, the paper towel idea worked and we'll see how it goes from there thanks again