Hortilux Metal Halide Blue 600 The powerful spectrum of HORTILUX BLUE is now available in a 600 watt version. 600W BLUE is a metal halide lamp designed to operate on 600W electronic ballasts or core and coil (magnetic) HPS ballasts rated ANSI S106. All 600 watt core and coil (magnetic) ballasts are HPS rated, therefore, the 600W BLUE is a conversion lamp on this system. Please note that there are no 600W Metal Halide core and coil ballast. They do not exist in the general lighting industry. That is why ALL 600W Metal Halide lamps are conversion lamps designed to run on HPS core and coil ballasts.