New grower seeking advice on nutrient deficiency (?)

[AndyMac]

Well, I was hoping to come onto this forum and proudly show off my little set up and beautiful ladies and pay the forum some tribute -but pride cometh before a fall it seems....

First off, I'm very happy to have found this forum. I credit this community as having put me right on so many things I cannot list.

I woke up yesterday to find these markings on the leaves. I have hunted pictorial guides and am guessing it's nitrogen deficiency. If so, what can I do to correct at this late stage of flower?

Appreciate the help very much.

 

[OldManGrower]

While not being an expert, I think I see white mildew on some leaves. The drooping tip may be from overwatering. I see no evidence of a nutrient problem.

 

[3Berries]

Some sort of white solid object on the leaf with yellow spot. Maybe a dried spray deposit?

 

[Rwise]

Pictorial guide is at the top of this page called "Plant Problems", link below also, take a look.
https://www.growweedeasy.com/cannabis-symptoms-pictures
I'll ask whats the PH?