1. Is there a big difference between using 400w HPS or 8 T5's, when going scrog? Light penetration isn't the goal here, so using 400w hps isn't waist of money? (the question refer's to a 1Mx1M grow space) 2. When vegging only 4 plants, is there any advantage using 250MH over CFL'S? sorry for my english and thank's
The main difference between them are the lumen/watt output, and light penetration. Also it's much more convenient to have 1, 400w hps bulb with a cooltube (no heat issues) rather than an array of T5's. To veg the 4 plants I'd stick to 6400k t5's though
If youhave height issues, I would use t5ho 3000k for flowering. I think you can buy a lower k rating now, just get the lowest k rating you can find. I've seen some pretty impressive grows with t5ho. Check out the t5h0 badboy light 12 lamp this thing will do what your looking for.