Growing pot size (volume)

20l minimum.

Depends on how large you intend to grow the plants. Same size as you need for regular seeds... It's the same plant. "they" say 1galloin per month or 1gallon per foot of vertical height. That's usa standards. I think these are okay for soil grows, but you get much more height and can over grow a pot more in a soilless context with little to now repercussions. so, method matters - soil vs soilless. Take a look at any solo cup competion of the peopel using soilles vs soil.. you can see a much more drastic effect of a small pot (small rootzone) on a soil grow than a soilless grow. osil might get 10-14 grams and the better soilless grows are 40+ grams froma 16oz pot. 3x larger from same pot size. I would not expect that to scale 1:1, though. if you do a short vege, can follow recommendations of a typical autoflower.. again, essentially the same plant and the only difference is a shorter time frame as to why you can use a smaller pot. in soil, err on bigger size, but when you harvest pull out the substrate and see how much it colonized the substrate.. if large zones are sparsely rooted, you can go smaller next time if you want. bigger is not "better" .. too big and your pot stays too wet for long periods of time and grows nasty stuff in rootzone. I use 5gal pots that are an actual volume of 3.6gallon (5gallon "compressed" fits is the reasoning.. stupid methods of measurement). If they sold a 4 gallon it'd probably be a better fit, and my grows are 95-105 days sprout to harvest. i shoot for 150-200g sized plants.

Depends solely on how much space and how many you want to grow simultaneously...

From start to finish if you plan to use no fertilizer you will need at least 7-gallon pot pre-loaded super soil. With fertilizer, mouses answer.

bigger the better. go as big as you can. I run a 2x4 tent and tent to go max 7gal or 26L that's if I'm doing 2 plants. if I'm doing more I have to shrink that volume. down to 2Gal or 4Gal