I don't quite understand the photo cycle thing, myself. The room in which my tank is located is always dark (there are no bright spots in this place *grumble*). Now I use a 60 watt pink bulb during the day, and a 40 watt red at night. I could just as easily leave on the red bulb 24/7 like I used to do, but the lighting really doesn't change in here. It's like it's always nighttime...
I understand the difference between leaving a red light on all the time and using a white bulb for only half the day, but how exactly does the photo cycles affect them if the red bulb is on all the time, but it's always dark anyway?