I have 3 plants in 5 gallon buckets in my tent under 600w led light running 18/6. The whole plant has basically turned yellow and any new growth is even growing in yellow. I'm using General organics nutes, using about 1/2 of the recommending amounts. I stopped using nutes last watering and am beginning to flush it. Can't seem to stop the yellowing.
^^^ I agree. I use LEDs and I had a problem with light bleaching and leaves dying when my 2 300watt LEDs were about 10 inches above the canopy. I raised them to 36 inches and slowly lowered the led's as the plants were bigger and stronger to be able to handle the light. Light bleaching with LEDs is a very common problem. Good Luck.
Not to be a an ass, but you may as well start over. If you can recover that plant it will take weeks. Better to start fresh and learn from out mistakes.