Thanks, I acquired a 1500w fixture that had a burnt up external ballast. I was thinking if you could find a bulb in the 3000k-4000k range it might raise bait similar to the original metal halide. 40k lumen and 300w with a $100 bulb is worth a try. Just figured someone may have tried it already.They work ok, you will have to bypass the ballast. I don’t think the Backside led’s reflect that well and depending on your housing your limited by size of the led bulb. I think I could only fit a 250w led bulb from Home Depot in my Hubble 400w fixture.