Is this light stress or nite burn

Growing under a 630 cmh. Have the light 31 inches above canopy. Just started noticed all the new growth yellowing now that I'm in 2 weeks into flower. These had been vegging for a few wks prior to flip. These started yellowing 2 days after feeding nutes. In FFOF. Using GH organics line

I have a lot of experience with ffof and can't recall ever seeing that. I am interested to follow. Have you used anything other than the GH Organic nutes.
You may need to list how often you used them and at what quantities. Not knowing what your problem is, my 1st guess would be that something was added to cause the problem but IDK.
Good Luck!

I've tried using other nutes with less success . Budha grow and bloom. I'm almost sure it nute burn. I fed 8ml bio bloom. 3ml bio bud. And some calmag. They still looked a little hungry 4 days later so I fed once again at same rate and 2 days after that is whem this yellowing appeared . So I flushed last night so I geuss we will see. Here's pics I took last night

Here's a better pic of the yellowing. It's confusing because the yellowing isn't isolated to just the tips nor is it wide spread. Just select spots , mostly near upper parts of the plant .