ventilation and trimming

so i have these 2 plants growing now, doing a cheapo setup. im living in student housing in amsterdam here, so i can't go cutting holes in my closet door and shit. i'm getting some grow practice for when i go back to the states in summer. anyways, so i have had these 2 plants for 10 days now, just put them into their bigger pots and i had a few questions.

im going to put them on 12/12 lighting, and i am currently w/o ventilation. since they were on 24/7 until now, i just left the closet door cracked a bit. however, i am having a goddamn hard time finding a little enough fan to put in there. i know the plants like as much darkness as possible in the dark 12 part of the cycle, so i ask...will my plants get enough ventilation/fresh air during the 12/12 phase if i have them totally sealed off during the dark 12, but then have the door opened a bit with a fan blowing on them for the light 12? by the way, i am using 3 100w CFLs

second, i have the GROW formula and the BLOOM formula, but do not know how much to add of each? i have heard differing combos/schedules, wanted to know what you guys thought. any combos/schedules that have worked for you guys might help me. also, you are supposed to mix those formulas with water and then spray them on right? if so, do i also keep a sprayer with regular water as well? or do i only have the 1 sprayer with the water, grow/bloom mixture in there?

third, this sounds dumb, but should i be trimming these plants to maximize yield/quality? i am going for shorter, faster yielding plants, if that makes any difference. if so, how should i trim and what am i going for? if not, when should i start trimming for best results?

thanks for the help guys, and i looked through the growfaqs and searched as much as i could, but i couldn't find very good answers for these questions. ill try to get pics up too, i know that helps

andy

Welcome to the site, apstoned!
I'll try to help.

You definitely want to keep the 12 hour dark periods dark. From what i read, the surest way to hermies is light during dark periods. You gotta do what you gotta do but if there is any way to ventilate while maintaining darkness - you should try to find it. Even one of those wee-little fans to keep the air circulating.

There should be directions on the nutrients for how much to use per gallon/liter of water or something like that. I am no expert but i'll tell you what i do when i switch to 12/12. For the first week of 12/12, i continue using the same Grow nutes. the following week (the second week of 12/12) i switch to Bloom but at a quarter strength (PPM) of my Grow nutes. Example: if i ended vegetative with a PPM of 1200 - i start off my bloom nutes at 300 PPM.

There is great debate about trimming but i think we all agree that pruning/topping/cutting should be done during vegetative phase only - if at all. Strain goes a long way to determining how short and bushy a plant is but powerful close lights, topping/pruning, tying, etc.. can also greatly influence the way a plant grows.

Student housing in Amsterdam? lucky, lucky bastard!