80x80x160 cm optimal plants size

150g plants x 4, maybe.. with a scrog. 4-5 week vege? really depends on the plant's growth rate and other relevant traits for yield. might find some vigorous plants only need 3-4 weeks to reach 150g size at harvest. yield is determined by light and size of the area -- oversimplifed. co2 obviously can improve yield with more light given than ambient co2 would allow. more plants will, to a point, reduce vege time. This may be critical to productivity if you do back-to-back grow cycles in perpetuity. This will shave time off your cycle and potentially get 5 grow cycles per year instead of 4 with proper overlap of seedlings/early vege. Basically, you could work it out so that your bloom time frame is what you divide 365 days by instead of including any vege time, since it'd be overlapped. if it's a one-off cycle each year... still saves time, which saves electricity. in some ways easier to manage smaller plants, but also more work transplanting and such. as far as pot size... figure 1 gallon per 1 month in the pot. if you do soilless, you can err a bit on small side in this regard, but don't stray too far. 2gallon or 3 gallon should be plenty for a very short vege period, similar to an autoflower's typical timing, except you get to predict it with 100% accuracy. so i think 4x11L will be fine as long as you don't over-vege. this will be something you'll figure out over time to make sure you fill the space but also don't over-grow for the space. that's just wasted time if you have to cut off excess congested growth. definitely use a net/trellis of some sort to maximize yield for area and support for the inevitable floppy plant you will come accross.