[Raul-7]

My photo-period is 12 hours total. It's on from 7am to 1pm...then on again from 3pm to 9pm. I don't know how to determine how much you need, I just got this from a suggestion.

 

[Raul-7]

I remember reading that it's beneficial(I can't remember why), but I think it's a rest-period for the plants. I just follow it since in nature it isn't always bright sun for the whole day...although I do know you are supposed to correspond your photo-period with the daylight period in your house.