I'm new to them. I bought 3 and they're all running on the 315W/930. I was prepared to buy both and swap them out but i was told not to waste my money. When ever I'm trying something new I go to the store myself. I trust the owner he's not trying to sell me stuff I don't need. And that's why I go this route with anything new. And I'll pay a little extra on the cost for his knowledge. The next ballast failure I'll be buying more. But at the moment I've got to many new MH & HPS bulbs in the closet. When I use up the supply all remaining ballasts will be sold and replaced with these.
I prefer the 3100k even for veg, didn't notice any benefits to using the 4200K bulb. Besides, the 3100K bulb puts out more UV than the 4200K one, which was surprising to me (don't ask for a source, it was a test on another site that I forgot. Ushio bulb put out more UV than the Philips).
I prefer the 3100k even for veg, didn't notice any benefits to using the 4200K bulb. Besides, the 3100K bulb puts out more UV than the 4200K one, which was surprising to me (don't ask for a source, it was a test on another site that I forgot. Ushio bulb put out more UV than the Philips).