How do i get the Plants to gain more height ? Is i...

Hi mate, as hashy said they double or triple in height when they hit flower. You can manipulate them to stretch during veg by giving them a little less light than they require, but hight isnt everything, I'd take a smaller compact plant over a taller one, its easier to manage. Hope this helps 🙂

When you flip into flower the plants usually double to triple in height.