I've been lurking this forum for a long time(2011), reading your guy's posts, following conversations up from 2009, reading the network of information from across the cannaforums and I just want to say thanks to RROG, tenthirty, Weezard, habeeb, Pet Flora and last but not least rives for being willing to work out the hearsay, put their money towards their own interests and being generous enough to share that data/experience with us. None of this would be possible without you guys, so again, thanks. My chamber is 4w x 7h x 2d, my grow style is top drip ScrOG, my strains of choice are NLxSK#1, Durban x Skunk #2, Chocolate Thai x Bubba Kush(Pre '98). I have been kicking around the idea of having two chambers one on top of the other, so I could feasibly get two grow spaces of 4w x 3.5h x 2d, but if I do this I need to make sure my wattages/distances will work out. I've spent the last three weeks researching the proper spectrum and I have come up with these LEDS that will suit our needs, I really want/need to make sure that I build this thing with the cutting edge tech/knowledge we have available right now. If there's a paradigm shift at the end of the month, so be it, I'm ready to build now and I want to do this properly. Cree XM-L2 WW 430nm: Exotic Hyper Violet LED (Would Prefer 5w) 465nm: Cree XLamp XP-E Royal Blue (Would Prefer 5w) 635nm: 5w Lumex TitanBrite 660nm: LZ1-10R200 740nm: LZ1-10R300 UVA/UVB:???? Do we even need UVA? I heard UVB is where it's at. 6:2:2:2:1:2 I am not married to any of these brands/lights, so please make some suggestions about alternatives. 430/465 Dimmable XM-L2 NonDimmable 635/660 Dimmable 740 on 15 minutes before and 15 minutes after WW's only. UVB: Unknown I know dimmable drivers are more expensive/less efficient, but I'm going for weight this time and I think the control will increase my yields. I am willing to wire up an arduino or a RaspberryPi for light automation/dimming control if it gets to that. So what do you guys think? Is the UVA necessary? Is there any way to integrate UVB into the panel? Should I split my cab up and make two chambers? (I could build 4 lights total w/off panel drivers) How many light sources should I need to eliminate shadowing? Thanks for the information so far, I wouldn't even know where I was at if it wasn't for these forums. Also a big thank you to KNNA, we'll never meet IRL but thanks for paving the way.