I am using a 1000 watt HPS setup with a 1000 watt metal halide bulb for vegging and it works fine. When its time to flower I will swap bulbs. I'm not sure if it will work with a halide setup and a HPS bulb. It will not hurt the bulb to try. As long as you use the correct wattage you should be fine. Dont put a 400 watt in a 1000 watt fixture. It wont work for very long if you do.