Switching light to bloom

for autoflowers you don't need to switch your light to a 12/12 cycle to induce blooming.. that's just for photoperiodic plants.. autoflowers will start flowering by themselves, even under an 18/6 or 24/0 cycle (that's why they are called "autoflower"). I personally keep them at 18/6 for the whole grow, as with lowering to 12/12 you just keep 6 hours of light from them that they can use to grow buds.. 24/0 can sometimes stress plants a bit if they don't have great genetics, as it basically means they get no rest at all.