How many plants and how big should the pots be on an 90x40 cm surface ?

less vege time = more plants. otherwise you have to wait for more growth to fill the sapce... more plants reduces reuired vege time, all other factors remaining the same. genetics will mostly dicate yield, if filling space well.. nothing you can do about that. with ambient co2 if getting 50g/sq ft it's probably pretty good. as far as pot size... how frequently do you ahve to irrigatte? too slow? too fast? and at various points in grow does that change drastically that you have to adjust? simple stuff to work out.

You can scrog only 1 plant or SoG 20 popsicles… The most important factor is not the numbers of plants, but filling up the light coverage as quick as possible. 1 plant will take a longer Veg but less efforts, less nutrients, less soil. 20 popsicles will require a lot of work, more nutrients, more soil, but you can fill up the light coverage in just 3 weeks Veg.

2 to 3 plants is about the max space you have. If you want plants to grow bigger in future then lighten up substrate. Like a coco perlite mix or dwc for future. Soil is the easiest , but plants will be small and have low yields.

Also so, wie das aussieht, würde ich maximal 3 Pflanzen in diesen 7 Liter Töpfen in das Zelt stellen. Ich growe in meinem 40cm x 40cm Zelt eine Pflanze in einem 8 Liter Topf. Eine Einzige! Und die nimmt das Zelt schon komplett ein. Also in deinem Fall, wie gesagt, maximal 3 Pflanzen in 7 Liter Töpfen. Happy Gardening 💪😎