I dunno about using these eight bulb T5 Tek lights for flowering. I did buy one recently, purely for veg, and for that purpose, it's great. It's got two switches on the front, each one turns on four of the bulbs. Doesn't get too hot. It's 40,000 lumens, which isn't a huge amount for flowering (even a 400 watt HPS does a fair bit better than that). But for veg, I gotta say, this is one dynamite light. I have no regrets at all on the purchase. I highly doubt I will ever try to flower with it though, although since you can get warm bulbs, it's clearly possible. I just doubt the yield would be very impressive. If he got 5 ounces dry, well, that's probably going to be pretty much the average for a 40,000 lumen light - in other words, for the power used, it's okay. If you are using one box for the entire growth cycle for security reasons or space reasons or whatever, then it seems a reasonable thing to do. Otherwise...doesn't really compare to the lumen-generating and canopy-penetrating power of an HPS light.