why you takin out a loan, just save up, you can start seeds and veg them for reaaaallly cheap its only flower that you need the high power lights for and you can veg for as long as you like, been vegging mine comin up for 2 months, and 2 paychecks have been rinsed on it (the whole project that is and soon to be a 3rd)
lol well I suppose you'll be paying it back in about 150 days XD providing all goes well, from what I've read on your other thread I think you'll have enough space to grow 4 quite big plants.
Humidity is good for veg, they love it (up to a point) its bad for flower else your bud gets mouldy... umm controlling humidity...
keep any unnecessary water out of the room during flower as the lights get really hot and evaporate it making more humidity.
good ventilation.
don't spray them when they're flowering.
I'm still on my first grow 52 days in XD just be patient, use common sense and you should be fine.
hehe yeah I drove up to scotland the other week for the weekend the weather said rain but it was well warm XD
your not growing in your attic are you? if -12 i would not recommend the attic as its the place that gets both the hottest in summer and coldest in winter.
I just grow in a closet in my room, works a treat!