BullitRoffa010

You've got a fairly substantial iron deficiency showing here. Are you using, by any chance, RO water for your grow? If you are, it contains no minerals at all and is most likely the cause of this deficiency... if you're not, then there are several other potential causes, pH being one and you've not provided any information on the pH levels you're maintaining... excess phosphorus can also lockout iron - but you've not provided us with any information on the nutes you're giving in what amounts... For a quick fix (and unfortunately temporary), you can get some ferrous sulfate and mix 1-2 oz in a gallon of water and use that to apply a foliar spray. Do this just before lights out, though. For a longer term fix, you're going to have to figure out what is causing this deficiency so here are a couple of articles to read about it - they mostly address iron deficiencies in a soil grow since it's pretty rare in a hydro setup but pick through as they DO address it.... https://www.cannagardening.com/info-courier_iron#:~:text=A%20leaf%20nutrient%20with%20iron,)%20or%20EDTA%20chelates%20(max. https://www.trifectanatural.com/problem-identifier/iron-deficiency-in-plants/ Good luck...