When and what size container?? please help

Hey guys I am currently on my first grow and chose buddha's white dwarf because it is an autoflower and is small (the most i heard it getting was 30 inches) so i figured i'd be safe growing this for my first time.

they are in their 2nd week and look great. they are currently in 3.5 square X 4 deep containers. when should i transplant to a bigger container and what size container should it be? i have gallon containers, but wondering if this is to small.

i have searched the boards and it seems everyone grows in bigger containers, but i am growing a smaller strain. any information would be great. thanks a lot guys.

if it matters i am using a grow tent and 4, 4 foot T5 lights at 6500k.

I grew 24 inch plants in 1.75 gallon and i felt they were a little small possibly rootbound not autos though id go with at least a 1.75 i wouldnt go smaller for any plant larger root system means a greater yield hope it helped

i've never messed with autos before, but i always start mine in clear 16oz beer cups then put them in a colored cup so i can see the roots developing. once the roots touch the bottom of the cup i transplant into a 1g pot. then as soon as they show their sex, i transplant once more into 3gal pots.

I use the same size pots and have no problems. They may just need more frequent watering later in bloom. I transplant my clones into 5in round pots and then transplant again into the 1.75's about a week after veggin

thanks guys, i'll go 1.75 to 2 gallons. ill find a use for the gallons somewhere