What is this?

This is the White Widow strain from Seedsman. One set of leaves is ate up with it and the set across from it is ate up with and it is starting to infect my Northern Lights. Is this the dreaded PM I've heard so much about? I have the chart from George Cervantes, but nothing is matching up. Yesterday I fed them full strength nutes for the first time if that helps, going to flush them real good.

Look for bugs under your leaves yet ? Use magnification for best results

Midnight Warrior said:

This is the White Widow strain from Seedsman. One set of leaves is ate up with it and the set across from it is ate up with and it is starting to infect my Northern Lights. Is this the dreaded PM I've heard so much about? I have the chart from George Cervantes, but nothing is matching up. Yesterday I fed them full strength nutes for the first time if that helps, going to flush them real good.

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They need magnesium. Feed some cal mag .

that is most definitely not powdery mildew.
my first though is spider mites.
it could be early stage mag deficiency.....a half strength shot of cal-mag couldn't hurt.
but look for mites...especially since it's spreading to a different strain

Ok just got done flushing, going to give them some RO water plus the cal/mag. For now the strongest magnifier I have is 10x will that be enough.

You should be able to see sounder mites with the naked eye. Little black spots that will move if u poke at them. If you don’t see anything like that then check your mag

nurrgle said:

You should be able to see sounder mites with the naked eye. Little black spots that will move if u poke at them. If you don’t see anything like that then check your mag

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Ok I didn't see anything like that on the affected plants. I fed them the RO water with the cal/mag.

Probably my own fault this happened, when I fed them nutes yesterday I usually put the cal/mag in when I give them the nutes. After reading the label on the back, it said Cal/mag wasn't needed when using all three base nutes. These are the AN nutes. So I will make sure that doesn't happen again. Thanks everyone.

tried buddy.kindbot.io on the image and the top suggestion was Magnesium.
You can try a few photos to guide your search for diagnosis