Yea i know that... but getting a HPS light it's just to mutch for me now. They are to expensive for me, and in my country. The cheapest ballast for MH is 325$ and thats ballast only, after that i tought it's worthles to search the price for a HPS light. So i will use CFL's trought the veg. and the flowering phase. ANd since i'm a litle short on height in my gorwing room i would need CFL's because they can be placed closer to the plant as the HPS.