in my experience i have gotten the best yield under 1000's with plants topped for 4-6 colas, with 1 sq/ft of space a piece (in soil/soiless medium). If you are not worried about plant count i would go with 30-40 plants if u are using a 5x8 area. U can veg 30-40 plants in a 3x8 no problem. If you are in a state where u are worried about plant counts and are going to be flowering a max of 8 for legal reasons, i recommend u make a bigger veg section, and veg like 16 plants allowing u to have a very long veg so they could be huge and u could get max weight out of ur 8-10 weeks under the HPS with 8 plants. Use the biggest 8 for your first flower cycle, make sure u take ~10-12 clones first. So then the next cycle the other 8 have gotten a 16 week veg and are massive. Repeating this process over and over and just using the biggest and best vegged plants as your 8 chosen ones.
