Desmoanswered grow question 6y ago I also had that problem with 2 of my plants that suddenly started turning more and more yellow, I couldn't do anything right, it's still my first grow. But after purchasing a pH/EC meter, a lot became clear to me; my pH after adding nutrients dropped so low that it made your soil more acidic and certain nutrients couldn't be absorbed. I adjusted this and the plants look a lot healthier again and have resumed their flowering and resin production. I'm not going below 6.2 pH from now on. Maybe this can help you, anyway, good luck moving forward!