Yip you got lockout lacking in potassium hard an I'd say most trace minerals rather then try fix the issue as your almost at flush stage id try workout why it happened. Usually I'd get deficiencies when it was colder so my soil temps would lower an plants don't uptake every part of the nutrient your feeding them. Water temps can also be issue heated water is a big help. Ph meter needs calibration or new battery lol 😆 I'd just flush an let them frost up then harvest u must only have 2weeks at most left ??