If your on a very short veg cycle (2 weeks) with the clones you may be able to pull off the 6 plants per square foot. If your planning on cramming all those plants into a small space why waste money on round planters when what you really need is some square planters. A quick lighting reminder, 5000 lumens for every 1 square foot. Each 23 or 26 watt CFL only puts out 1600 lumens.