Light Spectrum, Intensity and Positioning.
Many ideas, but hasn't anyone tried vertical T5's? Many people are happy with the results - just saying.
When choosing a light source/sources, there are some basic things you're gonna want to know:
1. Plants have different needs in different stages of their growth.
During Vegetative stage, plants like Blue light better (6000K - 6700K is kinda the best you can get from this spectrum)
During Flowering stage, plants prefer Red light better - there is a lot of info on the subject, right
here.
2. As you can see, there is a minimum of lumens per m2 to cover - so, the two things you will be considering the most, would be the spectrum of the emitted light and its intensity. The minimum you would have to cover would be at least 25 000 Lumens per m2. I don't know how big your growroom is, since I'm not really good in converting... and am a bit lazy, haha...
* light intensity is measured mostly in Lumens, its spectrum - in Kelvins or nanometers, when it comes to light sources. You can see what wavelength meets a specific color in Wikipedia. You can also see what's the connection between Kelvins and nanometers there, friend.
3. Mixed sources work best! If you're going with fluoro's, have half of them Blue and the other half Red. It would go like that: Blue-Red-Blue-Red-Blue-Red-Blue-Red.........
I tried growing with CFL's - I sucked, because I couldn't distribute the light evenly enough, so the plants stretched... After that, I thought "They're stretching anyway - gonna get a sodium" and bushed up a bit, witch only shows that you need to consider how you're gonna place your lighting, too - that is also very important, friend.
If you get 36 watt T5's plants can stay as close as 1mm or just be in contact and still not get burned.
Keep in mind that fluoro's require ballasts, while Compact fluoro's don't - that is also a great plus, if you ask me. Because ballasts also emit heat, so the best thing would be place 'em outside. At least that is what I'd do - donno how much heat they emit, but be sure you put the ballast/s outside if you're using HIDs...
I hope I helped you, friend! :)
Lots of Love.
Peace and Blessings,
the THC Lover.