you'll need at least 8 or 9 of the 23 watters. don't bother with the 9 watters. That's why everyone invests in a hps. I did the same thing as you when i first started. If i had forgone the cfl's and just bought the hps right off the bat, i would have saved a lot of money and not to mention how much better the quality would have been all that time. You save about $50 going with 9 cfl's over a single hps. Is that little bit of savings really worth it? It's only the price of one 1/8 of weed. Also, think about the hassle of moving 9 lights over moving just 1.