This Four-Tier Hydroponic Lettuce/Herb System with its 24 GT50 growing channels can reportedly produce 9,360 heads of lettuce a year or 180 heads per week. Measuring 8 feet 8 inches high by 4 feet 4 inches wide by 20 feet long, the capped channels provide a total of 720 1?-inch plant sites spaced 8 inches on center. The system, which is also used for herb growing, comes with a 300-gallon reservoir tank, inlet and outlet plumbing, a pump, and all the required fittings and adapters. Sold separately is a light kit that includes 28 two-bulb fixtures plus one 6,500K and one 3,000K T-5 bulb for each fixture.