I bought 2 600 watt E ballasts, and am already having problems. I got about 1000 hours out of a hortilux eye enhanced spectrum bulb. After I called customer service, I was told to put a new bulb in, as if I returned the ballast, and it works, I will be charged for the new one they send out. So I put my spare hortilux eye bulb, and it lasted a whopping 12 hours. So I guess My E ballast is eating bulbs. Ain't really right to ask for a refund on the bulbs when a bad ballast is causing the problem, but at $75 each, I may try to get one replaced.