Jef79answered grow question 5 years ago Hello.. Hope you are well.. I use canna pk in last few wks.. I know on bottle it says last 15days b4 harvest but in theory 7 of those days wud b flushing water.. I always work bkwards so if on a 8 wk schedule id do wk 8water..wk 7 wud get 1/2 base nuts n 7ml of pk.. I start to slowly give her pk at mid wk 5 at 0.3ml per ltr and very slowly raise it up as buds form.. Pk is very very strong..i never go to the recommended 15ml as find this to strong for my set up and always get tip burn from it.. Stay safe n gud luck.. 👍🍀