Beginner question about my leaves and ppm

[Damo]

I. Noobie here. Could anyone explain what’s wrong with my leaves.
600w x 3
Various strains
Coco
Gone to 1/4 strength and feed at 700 ppm ish

This one in question is a very old auto. Took 10 week to start flowering. Been about 4 weeks since. This one generally has a higher ppm run off but could this be mildew? That’s powdery stuff and the white and yellow blotches.
Thanks guys if you need more info ask. Thanks

[HappyHydroGrower]

Not sure on the mildew. Looks like it. I’m sure someone will be along and can tell you.

Maybe @Covertgrower @Myfriendis410 can tell.

Do you have fans blowing around your plants? What’s the temp and RH like?

[Covertgrower]

If it wipes off, it’s more than likely white powdery mildew.
Diluted peroxide mixed with distilled water applied to the leaves right before lights out.