If you can the best way to do it is to pickup a variable watt digital balast like the Galaxy so that you can vary the wattage depending on ventilation and heat issues. During the winter I use a 1000 watt, but during the summer I step down to a 400 watt because of heat issues. Not much change in finished product other than the 400 takes about 2 weeks longer to finish than when under the 1000.