Thanks McToker. I have just read the sticky concerning electricity costs, but that doesn't really answer my question.

What I want to know is, which lights (CFL or HPS) give the best results for the amount of electrcity they use? Sorry if I wasn't clear before.

Maybe there isn't a definitive answer and it all comes down to personal preference. But as I am a beginner, I don't know enough to have a preference! So any help would be much appreciated