Ok lets say you are in Week 4 of Flower, before its just been preflowers, If you switch to 12/12 it takes around 2 week until flowers show up, And for Week 4 they look very good, Dont hold on NUmbers, just look at the PLant, all leave are green all Hairs are white and your trichomes are probably clear/ beginning of milky, your plant will need minimum 4 week more. Look for good ventilation, Watch humidity to avoid mold. And kep that Temperature its perfect. You are already using Blooming fertilisers, look to lower them when the end comes (in anround 3 weeks) and give them MOlasses to feed the microbacerias in te soil ( helps the plant to absorb) Skip grow big.. it contains to much nitrogen, there is no need now for Nitrogen, you can add a PK booster or leave it like it is... just no more grow big