Mildew? This has been on certain leaves of my plants since I got them so I didn't think much of them. But as I'm about two weeks into flowering, I want to see if this is possibly an issue. Have okay airflow in the tent but could be better. Humidity is 55% atmosphere. Thoughts?
That looks like insect damage, but hard to be sure without seeing them in normal light. Either way, get a magnifying glass and have a look at the tops and undersides of your leaves.