general rule-of-thumb coverage for a 1000-watt HPS is a 10' x 10' area, but I'm sure you could add more wattage/sqft if you desired ... an old Rosenthal growbook claims maximum results are obtained at 60-watts per square foot, anything more is probably wasted ... I don't know how true that it is, as different types of lamps differ in lumens/watt ... :smokin: