It is always between 5.7 and 6.0What's your feed pH?
You had responses but never chose to reply back to them. Those plants are locked out dude, what mesium and grow style are tou running?Thanks a lot guys! Although I didn't get many replies here, but I want to give you an update. I fixed the issue in a week after this post. Not sure what caused the issue but looks like lowering the nute ppm and decreasing the light intensity helped and the yellowing stopped. The photo is week 6 day 6. Thanks guys!View attachment 1241312