They only seem to be on the new top growth of this one plant. I fed them Grow Big and Big Bloom a week ago. I noticed the yellow tips yesterday.
They look pretty good. But ff has enough in it to last 3-4 weeks wo nutes. That might be slight nite burn on the tops nuts I mean slight. I think they look healthy maybe give normal watering for a couple weeks and test runoff
Beautiful healthy looking plant I see nothing to be concerned about. Happy growing