"David Ritter" wrote in message ...
I've noticed an oil like slick with a blue tint on the edge of the water in
my power filter. It's a 10-20 gallon Whisper Filter that hangs on the back
of the tank. I only see this substance on the water before the carbon
filter. I clean the filter system and it comes back within a week. Any
thoughts?

Looks like we're all baffled by this one --

--Mark