You need more light and more fertilizer. Stinky's eyes are better than mine, but what I see is plants that are spindly from lack of light, and that have poor-quality, somewhat yellow lower leaves, some of which have clearly already dropped. Classic sign of nitrogen deficiency. Also, I think I see a little interveinal chlorosis (yellowing from chlorophyll die-off) in some middle leaves. Probably the beginning of yellowing and death from lack of nitrogen. If you see that yellowing between the veins of the upper leaves, it's too much phosphorus. Miracle Gro 15-30-15 can cause that by overloading them on phosphorus (the 30), which causes a manganese deficiency that in turn limits the plant's ability to translocate nitrogen to feed the chlorophyll. If you see that on upper leaves, toss a little epsom salts on them and go to a fertilizer that's lower in phosphorus, and they'll be fine.

I don't know what the consensus is on what fertilizer to use on weed, but Stinky's right for sure that it should have micronutrients. And what kind of soil mix is that? It looks like mostly gravel and/or Perlite, not the sort of thing that would be naturally rich in those vital micronutrients.
ohkelly Reviewed by ohkelly on . Fungus or a deficiency? :weedpoke:notice the color on the mainstem,is it a big concern ? Im been keeping the temp around low 80` and the humidity around 50,also have a fan circulating air Rating: 5