I came back to my plant today and noticed issues w...

It looks more like a phosphorus or potassium deficiency or both but the rest of your leaves look great in your photos. It could be an old deficiency that just became more pronounced because it was an older fan leaf. You are adding quite a bit of cal/mag I would lower it to 3 ml per gallon excess calcium can cause potassium lock out. Don't forget some of your other products have calcium in them already. Sensi Cal/Mag extra is a chelated product using EDTA which allows the roots to rapidly absorb the nutrients. Signs of phosphorus are dark green almost blue-ish coloration of the leaves with brown necrotic spots at the edges. It's also wise not to mix different companies nutrients and try to use their specific nutrient feeding charts if possible. Hope this helps.👍