Originally Posted by cjason3041
my ignorance....what is the difference between a HQI and MH?????
HQI is just a magnetic ballast type that in 250 watt flavor generally overdrive 250w bulbs a good bit more than electronic ballast and the other two types of magnetic ballast (probe and pulse start) used to drive MH bulbs. although here and often HQI is just what people use interchangably to describe double ended metal halides bulbs. ex: " I have an HQI fixture with two 250w bulbs" what they really have is a fixture with two double ended 250w bulbs.