yellow leaves this morning

these cheese babies have been through hell and have come out looking good, until this morning when "bleu" showed some yellowing on her poor little leaves. i looked at the def chart but i am not really sure whats going on as the copy i have is blurry.

let's see they are about 20 days old, were burned by a falling light, they were watered a couple of days ago, just water, no nutes, the only thing they have had is superthrive like 2 waterings ago. only one has the yellow, i know the one kinda looks like it but i think it's the picture cause irl it's fine.

maybe it just needs breakfast?

The first pic looks like its mutated. I give nutes at week 1. You PH you water to 6-6.3?

yeah it's scarred up from the light hitting it. but came out of it. maybe it does need nutes. i can do that. i gotta take off for a few weeks and leaving mrs sunnyboy in charge and i don't want her freakn out over the plants so i wanna get this straightened out quickly