i have a 2x2x 4 it's short. i took clones rooted and gave them a few days and then went to 12hr days. mom was short so I knew it wasn't going to be that bad. still crazy full tent 

you can do the same with an auto let it get a few leaves give it 12 but that won't matter to the auto look at my photo of the auto shooting past my light! 😀