Leaves Turning light green? Please Help

Hey everyone I was wondering if anyone might be able to help me figure out why one of my plants turned light green over the past few days. It had nuts burn a couple weeks ago so i flushed it then a few days later transplanted. Everything was going really good and back on track then this happened. Im wondering if it needs nutes but I'm nervous to give it ferts because i don't want to burn it again. I took a pic of 2 different plants so you can see the difference. Here are some pics. Let me know what you guys think. thanks again

Apply osmocote to the plant, that should fix it . guranteed not to burn and its good to carry the plant to full maturity.

Get some Epsom salts , mix a teaspoon per litre and use with your normal feeds until color comes back

Pity you didn't turn of the hps lights too...?