First grow issues.. can't put my finger on it, please help!

Ok so these are on their 6th day on the flowering cycle, they were switched to an organic fert which had fairly low numbers for flowering stage: 4-10-7.. might have used a bit too much b/c the upper leaves show a small amount of over-fert damage but the damage to the lower leaves/new growth towards the inside of the plant is a different issue i believe... The temperature is anywhere from 55-65F when the light is on and i would say about 45-60F when they aren't.. I know this is far from ideal but winter has come and the outside temps are definitely effecting them in their box. Would this constant cold weather be killing the lower leaves? They should be fine with water, they were watered the day before these pics and the soil is still pretty moist 3/4 inches down.. however the soil is pretty cool even with the lights on now.

Would too much humidity ever cause a problem like this in conjunction with the cold? Sometimes the humidity creeps up pretty high after watering since it is an enclosed box with little air holes & no intake/outtake fans because there is only the one cfl light and budget..

They are growing under a 125w cfl in a box about 1.5ft. x 5ft, any help would really be appreciated I want to help them!! Thanks

(the last pic is what they looked like right before switching to flowering stage)

I will flush them but can't get the ventilation issue solved right now.. no funds for that & would prob make too much noise.. as well as bring in cold air which would then require a heater.. haha