More points of light
600 W over 1000 W
more lamps mean fewer shadows and about 7 to 8 percent more light per watt
Example room
18 by 18 ft, about 324 sq ft (30 sq m)
Tables
eight 8 by 4 ft benches on metal casters, pushed into a 16 by 16 ft (4.9 by 4.9 m) block
One aisle
roll a table aside when you need to work, then close the canopy again
Three lamps per 4 by 8 ft table
about 5000 fc (535000 lux) on the canopy
Hang, bounce, and power
Height
about 3 ft (0.9 m) above the plants so the footprint spreads evenly
Edge foil
heavy foil on the outer reflectors at the walls sends rim light back onto plants
Walls
flat white paint catches anything that still hits the perimeter
Power
one example room drew about 16 kW (142 A). A 220 V three-phase, 600 A service is the clean fit; install electrical capacity before the lamps
One panel
plug each lamp to its ballast on a shared timed board so they fire together
Climate in a large sealed room
Air-cooled lamps
8 in (20 cm) flanges, about six lamps per duct run, intake and exhaust through the roof
Night heat
heaters on if the dark period drops below about 65 to 70 F (18 to 21 C)
Day cool
two 15000 BTU window ACs on at about 83 F (28 C)
CO2
tanks and a meter holding about 1200 ppm, released under the trays so gas rises through the canopy
Circulation
fans mounted above head height so they move air without hitting people
Irrigation on the tables
Pots
32 five-gallon (22 L) buckets per 16 by 16 ft table block, coir soilless mix
Tank
about 180 gal (800 L) feeding 360-degree sprayers
Early
water about once a week; peak veg and flower about every 3 days
pH
6.3 to 6.5 in this example
Feed curve
start near 900 ppm, climb to 1500 over 5 weeks, ease to 1000 over the last 4 weeks, then pH-only water for the last 10 days
Veg time
10 to 20 days by variety, then 8 to 10 even branches into a 7 to 9 week flower, about 2 oz (56 g) per plant in that run