Plants, Three Different Ones

Sorry just found this question. Looks more like a magnesium and potassium deficiency. The solution is to put your plants in larger pots sooner. The pots are limiting the size of the root system. I would skip the solo cups and start them in 1 quart pots yet water them as if they were in solo cups. As often is the case we all as growers te d to overwater on occassion this is actually one of the major causes of deficiencies. Always start a nice wet then dry type watering cycle starting around week 3. You ca also try supplimenting your nutrient routine with a cal/mag product @0.5ml per liter water a bit earlier in your grow to help prep her for bloom when they really start draining cal/mag for bud growth. Lastly older fan leaves are usually the first to fall and are usually removed during the first few weeks of bloom. Hope this helps your future grows.

I think it is a magnesium issue, possibly some calcium as well. You are using a lot of P and K especially with The Open Sesame. The other nutrients contain high amounts of phosphorus and potassium as well. Potassium and calcium are two nutrients that can cause magnesium lock-out when added in excess. Excessive Potassium blocks the absorption of calcium, magnesium, zinc and iron. It is a game of ratio's that you must play and when you add 1 thing it effects another. Happy growing! 👊