First Time Auto Flower Grow w/ 3 diff st

Switched back (Again) from the T5 to the 300w Vipar Spectra this week and has improved growth quite a bit. went a little too crazy on the nutes too soon this week even at 1/2 strength on all it seemed to effect my plants with minor nute burn. Also believe im having some PH issues (see pictures). probably going to ditch the mad farmer PH kit for a more reliable meter. if you cant tell already by now, im quite the noob at this! new growth isnt showing any nute/ph issues like the previous sets so i believe im in the clear..