gREEn7o0answered grow question 3 years ago Stems all appear green, likely not a cal,mag issue. Calcium is immobile and would have shown at the top, magnesium is mobile and would have started with old growth, but it also usually has purple show up in the stem.
It looks like you are going into flower, PK (phosphorus and/or potassium) would show similar to that.
Could be a deficiency, or it could be an excess or ph lockout.
You are running bottled organics which im not too familiar with, not sure if you can overdo organics that easily. I have however recently read about this brand someone else was having a similar issue. Seems the few people I read about running it found it to be fairly concentrated and were able to get away running lower dosages than recommended in feed charts.