Whats a good pot size for autos?

Depends how they will be grown entirely. In soil in particular it determines how large the plant CAN grow not will. In coco not as much, it determines how often you should feed it. So not enough info at this point. I would recommend 10-12L pots on principle, (3 gallons)

Hello I think it varies plant to plant, some have longer life cycles and those I always try to give bigger pots. But with indoor autos i usually stay with the 11-18 liter sizes. Occasionally I'll run some small ones 3.87 L and I've gotten some very nice plants, but I really feel like plants are definitely limited by their root space. I think your 20 L pots are good, being an airpot style you could definitely go several liters smaller and still get great results though because of the air pruning of the roots.

Heya! Most growers I have seen use 11.3L/3gal or 18.9L/5gal pots for autos. Depends on medium too I would say, you can grow some pretty big plants in 3gal coco pots. Cheers,