just water spots or powdery mildew?

Ok so I can't upload a picture at the time my phone refuses to let me but one day I decided to mist my plants because they were turning pale they had a super small amount of nutes in them which I forgot about till already sprayed, but the next day they had like spots like when water drys on a cup leaves those white spots I'm worried it's powdery mildew or is it just because I misted them there about three weeks into flowering autos and both have it it doesn't really look fuzzy like mold either

It's probably dried salt from the nutes. But just my 2cents.

Yeah that's what I'm hoping it's on the side of my grow box to and wasn't there till I sprayed them I noticed there getting small speckled dots to that if held up to light you can see through them

sounds like it I never mist with lights on as it does leave "blemishes" that can go black if not enough air

I didn't mist with the lights on either always do it off so it doesn't burn the plants