4th week flowering, suggestions/advices?

They will take up P and K during the first 2wks and again for 5 days 3wks before harvest which is why all the good bud boosters like overdrive tell you to use the boosters for 2wks from week 4-6 with an 8wk flowering period to catch those 5 days.3wks before harvest is when they put the most weight on but its catching that time when you don't know the strain so pk for 2wks from wk 4-6 if its 8wks finish.Ifn you haven't got access to hydro nutrients its shit and ash. Google when to use PK boosters. Advanced Nutrients are the best and have a great site with loads of info, made and tested on our plants.

Looking good! Not sure what your watering schedule is like, but maybe they could do with a bit more water - othewise they look pretty healthy. I think you've got a long time before harvest. I'm assuming they're outdoor - if so, you're at the mercy of mother nature. To my inexperienced eyes, I'd guess you've still got another 6 weeks of flower. Just a guess at this stage though. Keep up the good work!