besides lando's post:
if you don't have any corals or fish turn off your daylights and just run the actinics 24 hours a day. other than that, what lando said.
I ran my entire cycle on a 72 bow front with 2 96 watt actinics on the entire time. the tank is 10 weeks old and there is coraline growing on the dry base rock i used in the tank