Would really appreciate a picture of the affected plant…if this started in the lower canopy and is now kind of randomly moving up through the foliage you MAY have a Alternaria infection moving in. Yellow leaf #3 (left to right) shows necrotic margin lesions…green leaves (5-6) show very typical Alternaria symptoms…
FWIW you can often differentiate fungi infections from nutrient issues by the yellow ‘haloing’. Very easy to see the ‘haloing’ on your green leaves… You can search Alternaria in Cannabis or go to my website BudBusterPro.net for some actual photos of affected plants last fall. Been accused of ‘spaming’ so I’m not sure I can give website info…sorry if I crossed a line here