I have noticed that when I hit the autos with plenty of fertilizer early, and close bright light. I mean close too. I keep my leds about six inches over my plants. You will have to move the light up daily. When they hit fast veg and the stretch. They take longer to get to the blooming phase. Then when they do, I have been having everyone of them finish at no shorter then 3 feet. Some have been going over four feet, which I do not like. My test tent is 5 feet tall. It is well worth the extra time.