Plants leaves are yellowing; Stems turning purple and drooping leaves

Hello!
My first grow,
Setup:
-CFL grow
-Using seed started and cactus soil(Good draining soil)
-Plants are 2 and a half weeks old
-Unknown strain
-Light schedule is 18/6
-No nutes


I noticed that the shade leaves on one of my plants are turning yellow, and the stem on that particular plant(As well as others), are turing purple. I did have this plant in too small of a pot, and I re-potted it recently.


As for these plants, they are in the exact same setup, and I also recently re-potted them. Their leaves seem to be drooping and slightly curling under, and I do not know what the reason could be.


Any help will be appreaciated!

starting to look a little hungry .. I would pick a good fert or plant food at this point and start slowly introducing it at a very cutrate and feel it out from there ... good luck ... looks like your off to a good start .....

friend i have 2 that were like this there now 3 foot high still got the red stem thing goin on but dont think its to much to b concerned about from the research i did, plus on my previous grow i had the same thing goin on, still got gr8 bud m8, good look, they look good tome by the way.