I think from 1:00 to 9:00 for MH is good. also, I don't think you need UV light. I don't have one and don't see why I would need it. you probably just will need some small fans over the surface of the tank, because if the temp raises during the day, obviuosly because of the lights, if the temp will stay higher overnight, then the temp will go up the same amount of degrees as it does now. so, in the end you need a heater so the temp doesn't go too low, but you need fans so it doesn't go up so much when the lights are on. hope i wasn't confusing.