2 YEAR consistent Deficiency issue - Purple fan leaves

[dbrn32]

PH issue coco/perlite flower

Hi all, I just fed my plants to run off and found something concerning. Nutes going in were ~1400ppm w/ ~6.5 ph. The runoff measured ~1400ppm w/ 5ph (maybe lower, I use drops, not a meter). Should I be concerned, and if so, what is the best way to correct this?