Don't know how much headroom you have,NT,but those VBS stretch like a motherf**ker. I veg for 8 weeks and mine are the tallest plants in the room at 5 1/2 feet+. I start a modified LST at 3-4 weeks and tie down the main stalk until 3-4 other side shoots reach the top one. Then I untie it. Lets me have 4-5 main colas and slows down the rapid stretch.