A skimmer is the long term fix.

Not worth it in a planted tank, IMO. Clogs too easily.

I had a terrible problem with surface scum for awhile. But only for a few
weeks. It's completely gone now. I really think more surface agitation and
being careful with my fertilizing helped. I got lazy for awhile, and let the
nitrate drop to zero.


Leigh

http://www.fortunecity.com/lavender/halloween/881/