Try to start 18/6 and when the first signs of flowering appear for a few weeks switch to 12/12. I grew the car several times along with the photo and when I switched to 12/12 the car also gave a good stretch, which increased the yield. Twice this was the case and once 20/4 without a transition and the same strain grew small. My conclusion is that at the transition of 12/12 in the car, the part of the genetics that the photo and it gives the command to stretch is triggered. Good luck and good growth)