Nute burn and nitrogen deficiency

Hi all, back with more problems. This barney's farm auto blue cheese grown in biobizz light mix and bac nutes has burnt tips and yellowing rapidly bottom up. She's in her 2nd week of flowering and has been having 0.2ml root stimulator(concentrate) and 1.5ml of grow per litre. Any suggestions? Water has been going in at 6.2ph 350/400ppm.

I don't see anything to be too concerned about. I just finished some AK47 autos outdoor, feeding 900ppm of Jacks 321 every 3 days. Had no issues at all.