I don't think you need to add Zinc. You probably just need to lower the pH so it's available to the plant. I could see adding a little bit of micros but not too much...

Anyhow... mine seem better or worse depending on when I look. IDK, might just start over.

When I made my mix, I used coco fiber instead of peat at 25% of the mix. I always use peat, and shouldn't have tried to alter the formula (50% potting mix (FF OF or similar), 25% perlite, 25% peat moss). Then I add a little hydrated lime to counteract the lower pH of the peat, and it balances perfectly with water pH that is normally 7.3 around here and a low dose of Earth Juice nutes.