Plants grow tall and spindly and topple over because people don't use enough fluorescent lights, it's not from the lights themselves. It's about lumens per sq. ft., and use enough of them and the plants will grow just fine. It's much easier to use enough by going with HID though. Just make sure you use daylight (about 6000K) for vegging and even more important, warm (about 2500K) for budding. In general plants grow more bushy and shorter with blue light, and taller and with less nodes with red/orange light. There's lots of good info regarding your questions that I'm not going to repeat in this thread: http://boards.cannabis.com/basic-gro...hing-mean.html