Consulta

depending on efficacy of the light and hours of use, you'll need varying amounts of watts per sq ft. if faily efficient LED, you can do 35w per square foot over 12 hours per day and probably be near 'max' DLI relative to ambient co2 levels. for 18hours, you can use 66% of that 12 hour recommendation -- you can see DLI is 1:1 proportional to hours of use. dli = daily light integral. worth a read. hps you need closer to 50 watts per square foot over 12 hours.