My,temps were kinda hight,,for,a couple days,,and humidity, was high also,, due to power outages, now I'm back on track ,95. 100 degree, ,for,about,and,hour,or to
It may not be a bad idea to supplement some Nitrogen. I'm assuming the yellow started towards the bottom before it began working its way up?
You could do a light top dress of some guano like a 5-1-1.
But to be completely honest, the plants don't look bad. You could ride it out until harvest if you only have about a month to go. I wouldn't do anything too drastic as you could possibly do more harm than good.
ialways seem to get this when im 4 weeks into flower with Pro-mix, i feel like its a PH fluctuation outside of its range and so its not getting its nutrients, or its too little feed
If your lights are really strong or close it can sometimes drive the plants to really dig into the nutrients available.
I suggest you just have a look with a normal bulb as colours can be hard to read under grow lights.
If it is just nitrogen, the colour of the [plant will pick up in 2 to 3 days after you increase the feeding.