m0useanswered grow question 3 years ago BioBiz likes a PH of 6.2-6.4 if I remember correctly.
Also the runoff is at 0.5ec or 500ppm
That's too low of feed strength for Photoperiods.
look up feeding strengths and increase it slower as it starts to perk back up.
BioBizz also works well if you let it sit mixed up for 12hrs before you adjust PH.
It tends to drift downward.
Good Luck!