1st grow, 2x2 tent, Mars Hydro ts600.

Hi there! To me that yellowing looks like the plant is just cannibalizing those leaves 'cos she dont need em anymore. The reason I feel like this is that only those few leaves seems to be affected and everything else is looking healthy. I think that if it was bigger deficiency you should see symptoms on more leaves than those few. Maybe keep an close eye on her and see if this spreads before giving something more?