Here is some more info:

http://www.wetwebmedia.com/cfmarfaq2.htm

"F.D.S." wrote in message
...
I have a question about lighting again:
I have two 55w 10k and two 55w actinic blue PC's on my 55gal tank.
Inhabitants are some damsels, 1 snowflake eel, green star polyps, a few
mushrooms and brown button polyps. When it comes time to replace the
bulbs,
can I put 65w or 96w on the system? Or would it be a waste of money due to
output of light is dependent on the ballast powering it? Thanks for all
your
help.
Fernan