Don't forget the color temps of the lights are very important. Mh, cool white cfls, color 6500k= vegging mimicking summer. and hps, soft white cfls color 3700k= flowering mimicking fall. 18/6 for vegging and 12/12 for flowering. 24/0 is okay too, but the problem with 24/0 is that the roots do not develope as well as the canopy, which can lead to falling plants during flowering from the weight of the buds. I personally have never seen it while vegging my plants under 24/0, but have witnessed it with a buddies grow. Since then I have stuck with 18/6 for vegg.... Happy growing FAM....