I would get a moonlight setup, 2 lights is great for a 12. Then at night turn all the lights off except the moonlight.
I have a set ready to go, just need to find a power supply. Let me know if you are interested.
if you're talking about the antinics i turn mine on first for about an hour then have the whites come on and they run together until the end of the day and then i run the blues again by themselves for about an hour or 2 to simulate night fall then they shut off and i run moon lights during the overnight hours, then in the morning just the blues again and so on...hth