I'm hoping residual sawdust from when I installed the new light. I need to do a good vacuuming in there. Don't smoke and build! You forget to clean up... I can brush that stuff off with my hand or blow it off without much troubleWait what is this? First picture.
I've backed off on ppm and did a water change today so we'll see if that helps, and nothing goes brown or yellow first, just holesIt does not look like bugs to me. First pic looks like a mutation. Second looks like a tear. Third may be nutes/light burn.