\3g bags are fine. i start with cups, go to 1g, then flower in 3g. 5g bags of dirt are real pitas, better to have buckets once you get that much dirt going.
thanks they are in cups till 3 weeks i have a couple autos i might try first do you get problems like falling over when they go into flower would i be better off digging 2x2 holes directly in the ground