Way too young for nutes in FFOF, if anything it might be too hot. Bottled water, if that is what you are using has a PH of 7. You should PH your feed water, and adjust that to 6.2 - 6.5. I would stop feeding, and get your PH more precise say to 6.3, and stay there. It's really to young to be deficient in anything. Peacei added some fox farm Big bloom to see if that will help i did 1.5 teaspoons to a half gal. that brought my ph down a little to what looks more like 6.5 7ish im using a cheap soil probe ph tester i know they suck n are bad to use but its all i have . , so hopefully that will help it along with giving it any nutes if that was the issue