what should i compromise on, light penetration or temperature ?

time to flower the ladies.

i have two options :
1. 12 hours of dark will be during the night.
2. 12 hours of dark will be in the day.

the first one is better for light penetration
the second one will be better to control temperature.

the temperature here is somewhere between 15C \ 60F at night and 20C \ 68F during the day.
when the lights are on during the night the temperature is perfect 24C\ 75F.

i can minimize light penetrations but not sure that i can achieve 100% dark during the day.

so, what do you think is more important ?

does your grow room have a window that you are worried about letting light in? do you know what the temps would be if you have the lights on during the day? i doubt it would get more than 3 or 4 degrees warmer during the day but you would need to know for certain. if you can get away with the temps in the daytime i would just run the lights during the day. i do this because i want the most awake time i can have with the plants so i try to match them to my own sleep patterns. i would run the lights during the day and just watch the heat.

yes, it does have a window that i would like to leave a bit open to let fresh air get inside.
there is no problem right now to leave the lights during the day, the temps are perfect, the problem is during the night, when there are no lights, i guess the temps will be something like 10-15 C (50-60 F) .

i like my temps at 65 at dark and 75 during light

Its a hard one because if a plant does not recive the right ammount of light during flowering then you will find that you will lose alot of weight through streching.But saying that if the plants recive too much heat from a light this can cause stress and burning,but somehow you have to get both parts right it can be done.But you may need to get a cool hood or try haveing a fan blowing just up at the light hood this can cool the light down alot,its little tweeks that you will have to do to your grow space that will make all the differance.One other way is make a room that isfar bigger than the ammount of plants needed,try and have a exaust fan at the very top of the grow room has the heat will rise.Or even worth thinking about lowering the light from say a 600 to a 400 has you will be able to have this closer to the plant tops.