Basics

Btw, I can't actually see any mildew from those pics. Like, at all.

Some things I know about are citric acid, potassium carbonate/bicarbonate, epsom salts, even MPK, plant oils/phenols, lactic acid stuff (like milk) and some bacterias. Lower humidity (though mildew can also often result from drought). And of course, weaker plants are more susceptible. Especially if they have thin leaves that don't have a decent waxy coating.

Hmmmm mould only really starts if the humidity is way too high and event then its hard to settle because of the fans in our tents. Though of the top of my head I know diluted milk works. Though here is some more information I found online for you to combat powdery mildew :) https://www.gardendesign.com/how-to/powdery-mildew.html Peace out and good luck