if you hang them vertically you can have 2 rows of plants on either side, stadium style and you will get much more efficient use of the light. if a light is horizantal then half of the light produced must be reflected down to the plants there is no way around it unless you have one of those 360 gi grow systems. whether or not the light is reflected by the bulb or housing it is still reflected. as i said your grow looks excellent, i was just giving my 2cents. if i had that kind of space i would grow stadium style no question. that is how the large indoor "cash crops" are set up to get the most use of light/space. anyway, keep up the great work and keep use updated as to the progress of the grow, what are you shooting for yeild wise?...4lbs? i think that is a good conservative expectation for a 2.5kw (1st) grow. i could be wrong though my biggest grow was a 400hps scrog in a 2'x4' closet with yeilds close to 1lb. currently i have no grow due to legal issues. i would definetely like to hear your thoughts on what you are expecting. btw do you have a separate veg room. if not you should think about that as well. i had a 2'x4' veg chamber with 8 4ft argosun full spectrum (t12)flouros. with that i was able to supply 3 flower chambers so i could have 3 full harvests every 7-10 weeks, strain dependant. sorry about the long post. and if i haven't already said it your grow looks great!!!!!!lol