It may not be the Bounty or wattage. Some flowers will get taller hydroponically. I always look for flowers that are shorter or at the recommend thread. What I have learned over the years is that a lot of it is trial and error. Also while some flowers say they only grow x amount of inches they do not take into account the tall stems of the flowers, Thumbalinas are one example. The stems grow 12-14" but then after that last upper leaf they only grow 4-6" Very misleading, hence trial and error. I look at pictures online now to see how they actually grow,.