Thanks for the reply Zandor. So basically they're a better all-round bulb that I can use 4 veg & flowering. Is it still advisable to use fluorescents for the 1st few weeks & then use the light I have? Or can this light be used 4 the whole growth of the plant? If not, then when is it recommended to start using this light. I have my plants (seeds at the mo - 1 sprouted yesterday) under fluorescents but thinkin I may get better results just using the PSL. Any comments mucho appreciated