Roots getting brown

That isn’t a ph issue, that’s a calcium and magnesium issue. Being off by 0.30 or 0.60 won’t make a difference if you were 5.9 lower or 7.1 or higher I’d be an issue. The spots are from the plant starting to rust up from calcium def and the fanleaves yellowing like they are are from a magnesium def. the lime green tips are new growth and it’ll get darker as it grows. It’s usually sometimes it’s one of those two deficiencies or the other but some strains do both if the plant is more adaptive to being acidic. Buy some cal mag plus cause it has nitrogen as well and use it every other watering. It’ll work itself out with a few weeks. I use 2.5 ml in a half gallon once a week and 5ml when I give a whole gallon. Other than the magnesium issue they look great and good job on the veg.