White spots on my foliage

Hello Yes you'll definitely get some leaves that start to fade as you only give plain ph'd water. But this looks like something more. If you take a wet towel will the spots wipe off somewhat? If so probably a pm situation. If not then probably a pest in the yard, could be thrips or other. Get some close up shots of the under leaves and see if you can see any spots down there or raised bumps. If there are id recommend making a soap spray bottle 3/4 water 1/4 Dr Bonner's castile soap (or dish soap works, but castile is the best against bugs and gentle on the plant) and that should kill off any pests and may even help to wash away and powdery mildew spores. Look into a couple things and see what you find.✌️