hey,78,u should think about 400 watt.400watts only penetrates 2feet.start flower cycle 2FEET TALL.12HRS LIGHT 12HRS DARK.THIS WILL KEEP PLANT UNDER 4 FEET.ALSO U WILL NEED FAN TO KEEP PLANTS COOLER ALWAYS KEEP LIGHT ON 400 WATT 2FEET ABOVE PLANT.GOOD LUCK.