Originally Posted by teen
yea, im pretty sure there the same. there both metal halide lighting. MH bulbs are just the screw in type that you would put in a regular household lamp, and hqi are double ended, meaning that they ar connected on both sides of the bulb.
the first pic is a regular MH bulb, the second is a HQI
A HQI bulb will penetrate deeper than a single ended. I believe they are also more energy efficient.