Sylvania GroLux High Pressure Sodium grow lamps are dedicated horticultural lamps designed by one of the worlds’ most respected lamp manufacturers. Sylvania GroLux HPS lamps are regarded by many as the best dual spectrum High Intensity Discharge grow lamp on the market as the brand has been tried and trusted by growers for years. The GroLux lamp is for use during the flowering/fruiting phase of plant growth but is also suitable for growing plants in the vegetative or ‘Grow’ stage. Please note that HID grow lamps must be operated in conjunction with a ballast and reflector. Sylvania GroLux lamps are available in 400w and 600w models.