I think Farmer has it; CFLs are great for vegging and have even used them through the entire grow. The trick is the amount of lumen; my experience is that you need approx. double the wattage of CFLs to equal HPS for flowering. The fact that doing this brings your power usage back closed to the HPS level. I currently run CFLs for all vegging, including seedlings, clones and the infirmary. I have never seen stress when switching from CFLs to HPS but you gotta keep your temps relatively constant; can't place the HPS near as close as the CFLs from the plant too. I have HIGH hopes for LEDs but the cost is prohibitive and their results have not thrilled me yet. CFLs are loaded with mercury and that ain't good. The real deal is gaining as much research and as much experience as possible. Growing, like life is a learning experience. Good luck.
