I have a noticeable leaf issue with one of my plants. The edges are rusting / yellowing and the bottom fan leaves are tuning yellow fairly rapidly. I’m using general hydroponics nute line. pH of water is coming in at about 6.3-6.2 in 3-gallon felt pots of coco. Using 2 LED SF-1000 lights that I recently moved to a distance of 15in. from canopy (They were at 9in). I have 3 plants in total and only one of them is showing signs of this issue.
Any suggestions on how to fix this issue would be greatly appreciated.