could be...could also be potassium def. if you dont have cal mag...use 1 teaspoon of epsom salt per gallon(magnesium) and 1/4 of a antacid broken up into a powder per gallon. if you dont have antacid I hear you can HARD boil 4-6 eggs in water...then let the water cool to room temp and feed your plants that. The calcium from the egg shells goes into the water when boiling.
it's not the entire plant! only select leaves that picture was the worse looking one all my girls are in the same soil, same nute regimen, water schedule, light etc. and just this one has the problem. . . none of the lower leaves are doing this starting about in the middle and working it's way up only effecting the larger fan leaves 0.o shits weird but has me worrying, I'm at the end of week 3 of flower
Leaf tips up? Praying for magnesium. Add the spots for confirmation. 1/2 to 1 teaspoon epsom salts from Walgreens in a gallon of tap water if nothing else. Calcium and magnesium deficits go hand-in-hand.
let me ask this. . . is it possible to have salt build up? not sure how that looks but I'm in 5gal fabric pots and the bottom of the pot maybe showing signs of salt residue. . . which in itself is weird because my last 3 watering's where straight water, and no besides the spots and yellowing from the tips the leaves are relatively healthy if that makes sense
Was using Fox Farm Grow Big whichs NPK is 6-4-4 then went straight water for flowering in week 3 or 4 now last watering hit them with some grandmas molasses, and just watered the one with the problem with some Epsom salt. . . they've all been given the same thing (besides the Epsom salt) and only one is showing signs of a def.
i have the same issue....i became convinced i had multiple deficiencies went with cal mag and some more food at 600 ppm things seems to responding well but its only been 24 hrs...i had purple stems too and im pretty convinced i didn't over feed. any pics of the whole plant?