Help with yellowing tips indoor Siberian autos

[Xsoldiercloud]

Hey guys first time growing my medical girls. I am growing 2 Siberian autos 1 girl scout cookies and a kush Dr. All autos. All from seeds. The seedling phase was tricky with a 600 w HPS light but we made it. I am now getting yellow tips and slight curl of new growth on one of my Siberian autos. I stared feeding 2gs of megacrop per 1 gallon of water for a few waterings. Things were good until the 3rd feeding about 2 weeks ago. I went with a little more nutrients at about 2.49g per gallon of water and fed all 4 plants. 3/4 plants saw some good growth but 1 Siberian auto got fuzzy with yellow tips on new growth and some slight curl. I have been witholding nutrients on her thinking it is nutrient burn and just giving her water but she doesn't appear to be going back to green on the new growth. What should I do? Just keep watering her normally while i continue to feed the rest? I have resumed nutrients back down at 2g per gallon of water on the other 3 plants and they all appear to be doing great have all started flowering and generally all look happy