Help Identifying Problems - Calcium deficiency?

Ive got 3 plants each with a problem or maybe its the same problem in all three? They are in Foxfarm ocean forest soil. They are on pureblend nutes with budcandy. 10 days ago I spotted some white powdery mildew so she got sprayed with some SaferGro Mildew Cure and Humboldt Sticky wetting agent. The White Widow was looking a little yellow and showing some brown spots so with someone else from the forum's advice I flushed the plant and started them on some veg nutes and some molasis. The 4th and 5th photo are from the WW plant now. I am seeing a bunch of little white specs but only on the surface of the leaves they don't go through the leaf. This looks similar but just smaller dots to the plant in the 1st and 2nd images. Is this a Calcium deficiency or could this be some kind of burn from the mildew spray? Lastly the 3rd picture is from a Platinum OG plant. It looks like nute burn to me and the plant has been cut from nutes but while I was posting I wanted to make sure.

Thanks!

It could be many things but I'm not thinking Calcium deficiency. When I looked at the leaves I thought pH damage with some heat issues. After reading your post I think the foliar spray and PM are pretty obvious culprits. If droplets are left on the leaves under full intensity lighting this can cause localized burns like you are seeing.

I'd be careful with the pH right now anyways though. Drop your humidity to 30% also to help with the PM.