Babies are looking pretty good, but just in the last couple days, I've noticed some yellow fringing on the bigger leaves of one plant:

Attachment 290626

Should I worry? The other plant (same seed, identical conditions all around) isn't showing this. I thought it might be due to drying out a bit, but maybe not? Went 6 days without water, but the mix was still damp (and I'm still learning). Watered last night and used the same formula as before; 50% strength of the FF hydro nutes, pH balanced.