Superthrive as no effect on auto strains. Just thought I would let you know. F1 crossing does created a semi auto or photos sensitive none auto hybrid in the F1 generation through. More hours of light and bigger pots give bigger auto's regardless of feeds hormones ect. Best thing to do with auto's imo is breed then to a out cross for 7-8 generations then breed for the auto trate then breed to a kick ass sativa and ask if auto's are anything like ruderalis lol.