It's hard to tell. Does it rub off? What does the bottom of the leaf look like?

That bloom pattern is not powdery mildew. You're fine, man. Don't worry about it.

Also, thoroughly inspect the undersides of each leaf with a tiny white dot. I see several leaves with solitary marks. They may be specks of perlite or sap sucker marks. If you notice an increase in these specks, and they begin to grow lengthwise, you may have thrips. They are small yellow worms about 20 times tinier than a grain of rice, often seen around the tips and edges and veins of new growth, or underneath shaded growth.