I have 1 32w 6500k white light and 1 40w actnic blue light in an unplanted tank.
blue: 7:00am-11:00pm
white: 8:00am-7:00pm
The two lights on together bring out some cool colors in the fish. The blue light only in the morning and in the evening is kind of for a dawn and dusk thing. Plus, the more shy fish will come out when only the blue light is on. Both lights are on timers. Also, no algae bloom; however, I do have a fair amount of algae that grows on the decor. Could be the lights, could be that the tank gets natural sunlight for about an hour in the morning. Pleco has plenty to eat, plus I think it looks natural.....except on the glass.