i'll thik i go with 15 then, but how much buds can produce 12 inches plant?

400 g end result, or am i dreaming?

hm well sea of green is best when u have lights that cover more surface area but don't penetrate very deep into the canopy. Like flouroescents or a few 250W HPS. A really good reflector can solve this problem but then the light has to be further away.

I think your results would be much better if you got a Cool tube on that light so you could get it nice and close and just blast them with lights. Lights loose intensity with each inch. Its more efficient to concentrate your power on a smaller area.

I would set up 6 plants in 5 gallon buckets and let them get pretty big but top them a lot. ESPECIALLY if youre using a big bud hybrid this SOG shit won't let your ladies reach their potential. If you keep the light real close and have your shit well ventilated you will get some monstrous buds. trust me when your hanging ounce and half ounce buds youll be glad you didn't set up a pussy SOG grow.