Hi
@Leeguan! What you're having here is a Nitrogen Toxicity, also called "the claw" because top leaves usually look like a bird's claw (curling downward). This can happen because of too much Nitrogen in the feeding solution - of course, but this can also happen if the plant doesn't get enough light to "transform" the nutrients into energy. Now as a solution, I'd recommend to stop nutrients now and until harvest. Nitrogen toxicity is known to give a very bad taste to the buds, so it's important to start flushing as soon as you can. If you can give this baby more light and less nutrients, while controlling the day&night temperatures, she should be fine. Hope this will help, keep us up-to-date and happy growing đ