Pot size

No not necessarily. You can go as big as you want indoors. But 5 gallon is a good size. I normally do 3 gallons but 5 gallons are an option. I did 20 gallons earlier this year with an auto

In my opinion, 20L pots size is plenty enough for an autoflowering. The plant life cycle is very short, the root ball isn’t that big and doesn’t grow that much.

Hey Buddy you asking if Auto-Flower Pot Size Indoors — Is 20 L / 5 gal the “Maximum”? Short answer: No — 20 L / 5 gal is not a hard maximum. Long answer: pot size does not automatically equal plant size, and bigger pots don’t guarantee better results with autos. 🧠 The key misunderstanding Many people think: “Autos stay small, so they don’t need big pots.” That’s not quite right. Autos can grow very large indoors — but only if everything else is aligned: • genetics • light intensity & distribution • environment • root health • timing (autos don’t wait for you) The limiting factor with autos isn’t space — it’s time. ⸻

A larger pot size doesn't necessarily mean a bigger auto, because the vegetative stage is relatively short—only about a month. That said, you have to stay on top of nutrition more closely in a smaller pot to ensure it grows well. In a larger pot with good substrate, the plant has easier access to nutrients without needing liquid supplements right away; however, sooner or later you’ll need to fertilize, as autos are hungry plants. I would use 15-20 liters per plant, depending on the available space, and fit at least 4 plants in 1 m2

20L would be maximum size I'd go for with an automatic. 16L will probably be just as good.

hi Harpoon............. Umso mehr Platz die Pflanze und die Wurzeln haben, desto grösser werden sie 😁 Zu gross gibt es bei der Topfgrösse nicht 😎 kommt natürlich darauf an, wieviel Platzt du hast...... Viel Glück😬

You can use whatever size you want, there isn't much point going bigger in my opinion

Will you can go ask big as you want, it's more space go the root and for the plant to grow. Just not a space efficient.