Depending on the strain, it can take a bit longer for some to finish up. Once you start seeing extensive yellowing at this stage, and you see that the same feeding you were giving it in mid flower isn't having an affect anymore, meaning leaves are still turning yellowish and orangish and such, it means the plant had enough, you can give it a 2000 ppm feed and the only thing it'll do is make the buds harsh and metal tasting. Just keep an eye on the trichomes, the ideal harvest window happens quickly and you have a couple days to chop it in that time frame. The only thing you have to worry for from here on out, is keeping your temp and humidity in check, as powdery mildew/mold are your only enemies from here through curing.
