Typically that's a Ca deficiency, but other things can cause that too. Without other symptoms, i'd wager Ca.. typically a neglected nutrient in many brands... just stupid, really. if your brand has a strong Ca portion, then look into other causes.
ugh advanced nutrients.. Used it first, researched after hate that stuff now.. Your soil is loaded with nutrients and ph buffers from the Advanced nutrients product... Kind of wish they would stop selling products as Cannabis friendly because they are obviously making products to make money and not to actually assist growers.
Hello.. Hope you are well.. At first i 4t it was overfeeding then noticed her tips aren't burnt.. Only thing i can think is wots her ph at? .. Are u feeding her at all?.. Is she getting wet leaves at daytimes?.. Definitely a deficiency of sum kind tho.. Stay safe n gud luck with her.. 👍🍀