It's pretty cold where I am right now, it can get to even 40F at night (but inside probably no less than 50F) Can the plants survive this? They've just germinated so I don't know if they can take it?
I'm wondering about this to. My light cycle is during the night and reaches 76 F during that time and lights off during the day sometimes drops to 56F is this to much stress for the plant?
Nah.. think about all the high plateau / desert areas like Afghanistan where there's shit loads of weed. Those places get cold at night all year long. It's not ideal, but few things are.
My room gets down in the low 50's at night and in the mid 70's during the day and my plants are just fine, If anything the cold will slow growth, but not alot and it may make your buds turn purple Good luck, you'll be fine!
a buddy of mine has been growing out doors at his cabin for around 7 years now, during the summer it reaches about 85 on a good day and usually drops to around 40-50 at night and he racks up the lbs.
Oh and a tip, since your lights throw off heat, put your lights on during the coldest time and off during the warmest. During the winter I also move my ballast into the grow area to add extra heat as well.