When to switch to 12/12??

Hi there! I think if the girls are trained the way you want them you can flip to flowering. Make sure they are growing healthy before flipping so they continue to grow that way too. I would do lollipopping and some defo now when you flip and after 3 weeks of flowering one more defo. This way your main colas will get huge and all the energy goes there and not to the lower bud sites.