60x60x180 cm Growbox... What do u prefer? One big ...

There really isn't a wrong answer here, it really depends on the style of grow you want to do and how crunched for time you are. The more plants you grow the faster your canopy fills up so less time needed to spend in veg state. More plants also gives insurance in case there are any duds in your batch or bad phenos. More plants also means more work caring for them though. If you plan to SCROG under a net, I probably wouldn't do more than 3. If you want to do a SOG grow in small pots you could probably do 9, maybe 12.

Good answer by numbers. I'd aim for 1-4 as well. have done 3 and 2 in a similar setup. I think it did well overall. The 3 plant one was going to be 4 but one of the seeds was male so I killed it. 12/12 from seed is also good. but plants will not flower till they are mature and that can take aorund 4-5 weeks. Do what you think feels best at this point and do it based on how many seeds you have. Good Luck!

Fastest and cheapest would be 4 plants with little to no vege time. Just go 12/12 from seed, maybe 1 week of vege? It's wise to have some space away from walls, so a slightly smaller than 2'x2' plant prolly takes anywhere from 4-6 weeks of vege to properly fill that tent with 1 plant - depends on grow method as well as genetics. *method being soilless/hydro vs soil.. whether you lst or top shouldn't impact this as long as it's done right. 1 less month of electricity is not a huge amount, but also 1 less month waiting for harvest. plant 6-8 so you can kill any weak or retarded plants. Even if you go with 1 plant, plant 2-3. There are qualitative reasons to go with 1 plant, but as far as cost and productivity, more plants is better. More plants also hedges bets against a turd genotype. when you do get one it's a smaller portion of canopy vs 100% of it. symmetry helps.. symmetrical growth is easier to shape into a square than a rectangle. Trying to make a plant oblong can be the cause of needless excess vege time and extra pruning of wasted growth on the short dimension side. I'd stick to 1 or 4 plants. 9 would be too many in 2x2.

one big. 40x40 per plant if you ask me

I have in my grow box 60×60×180 two plants. At the moment I wanted to try with two but next time I will try with three plants without using the SOG method. I guess I will use the LST method

If you're running hydro or coco and a photo periodic and you can let her veg for at least 4 weeks in that case better only one. If you grow in soil with autos or if you use the SOG technique, better 3/4 plants (but you should be prepared to manage them, so it depends on your experience)