My plants stayed short for a while too. It wasn't until I turned the blue spectrum down that they got some stretch going on. I'm starting week 3 of flowering today, buds are just now starting to really take their shape with white pistils starting to show on all the bud sites. One thing I learned from my first grow, is the most important thing in growing is patience! Especially with LED's, the plants take longer to flower, but if you just keep at it eventually you'll be rewarded