As I said earlier, we really need to do this experiment with equal lumens and equivalent lighting structure (side lighting, etc). But I am really intrigued with how the T5s are performing here. Couple of questions OMB...Are you confident that the group of plants here are genetically stable? By that I mean are you confident you are not seeing phenotypic variance unrelated to lighting? I ask this because the 4 girls I am flowering are supposedly seed from a single cross, but one of them has a distinctly different growth habit, ie lankier, longer internode distance, and overall "thinner" appearance. Also, are you using a single temperature of bulb in your T5, or are you mixing kelvins, and if so, what is your mixture? Apologies if you've already covered this earlier in the thread.