Phals under lights?

[Phal grower]

Thanks for the quick reply Gage, that explains alot in a very confusing topic for me. Now I now what "k" means and am very thankful. You explained it in a way that I can finally understand. I think I'm going to try T5's, but maybe 4' lights. What distance do you keep your lights from your plants, and what would you recomend for 4' lights. It is amazing what I do for these plants. Sometimes I don't understand my own fascinacion lol. Thanks again.