Robertsanswered grow question 10 months ago Looks like the leaves have been wet under the light being on. When I had issues exactly like this it was russet mites. Which are crazy tiny. Need 60x to 100x magnified to see. I soaked (30 min), and rinsed my whole garden about every other day for a week with neem oil mix. It eliminated the issue, and has not been back since. Looks like it is spreading to other plants as well.