I have a 400 Watt lumatek ballast (the purple one) and it has settings for 250,275,400,400sl. So can I run a 400 Watt Hps at 250 or do you run the proper wattage bulb for each setting? I ask because I currently have 400watt bulbs and its getting to hot so I thought mabye I can run it at only 250? Anyone know?