You could do SOG and pull out much more and use your space more efficiently. You could grow 90 plants under 3 600W HPS with each plant pot taking up 1 sq. ft. in 2 gallon pots. Each plant would be 3ft tall at the max so you would throw them into flowering when they are about 6 inches tall. Make clones wait a week for them to root and a week to veg then flower right after; you could be getting harvests every 2 months. You could easily pull 2 lbs. per light.