i would go with bigger wattage in veg a 250 aint shit
You'd be surprised how good the lower wattage lights are when used to their maximum potential, just pulled 3oz, +/- a few g, per plant from a 250w (3 Plant ScrOG)
so i think lol i say THINK i have the lights settled now i need to know how much of my loft i need to section off to do this comfortably and what an ozone gen costs to keep it in check
also is it better to keep the plants tight togher or space them out a bit was wondering if spacing them out to much will waste lumes on the floor and would it be a good idea to plum water up there and heat OMG i walked around up there yestarday to try and come up with a lay out and just about shriveled up like a raisin it had to be 140deg up there its a steel roof with no insulation i wanted to exchange my air from inside the loft but i dont think this will be possible with that much heat and i dont want a air con the size of a pick up truck up there to cool it all
Haydoon has a point, you will most likely have to insulate the shit out of the loft space if not to keep the heat out in summer but to keep the heat in when winter comes, literally do it up like a liveable loft conversion but instead of a bed and wardrobe you have hydro pots and HPS's XD
Is there any where else you can grow? I'd consider shelf based, stacked up system with 5+ shelves (a light on each shelf) and ScrOG with a shelf for vegging mums. With 4 flowering sections using 8-10 lil' clones a shelf (as soon as they have roots) 1 shelf every 2 weeks should start bringing in the sort of weights your looking for. But hey that's my opinion as a micro stealth grower
Stay Frosty!