Ya thats what I thought but it started when I wasnt giving any fert, jus plain water, and Ive been using the same mix for a bit. Its 2 tbls to gal. water of Fox Farm Tiger Bloom.
I see the cotyledon leaves have dried up and the 1st and 2nd sets of leaves are yellowing. Yep, it's time to start your nutrients at 1/4 strength. In soil, watch the cotyledon leaves. When they start to yellow it's time to start the nutrients. Good luck on your grow!
next time transplaant about an hour to lights off, this gives the plant to recover and not stress that much. try giving it 1/4 nute of cal mag, probly a defficiency