Royal Creamatic 250w HPS

These last couple weeks she started to go yellow, I thought it was a ph/nute problem considering that all the plants had similar symptoms. I gave her some more nutrients to see if it was missing some but it didn't do the trick. After thinking and trying to figure things out I realized it might be temperature/light related. I increased the light distance and added more fans to help with air circulation, after two days the yellowing seems to have stopped and bud growth is getting to normal, still gonna wait a few days to see what happens. Glad to hear your thoughts on this.