Can apple cider vinegar for Powdery Mold burn leaves?

[Southpw]

I have some powdery mildew on a Banana Kush outdoor grown plant in week 7 of flowering. I have been treating the plant with apple cider vinegar (1Tbsp) for 1 liter of water and spraying entire plant with it. In locations of mildew, I see burnt spots on those leaves. In unaffected areas, some leaves look like they have small white dots on them now. Can this mix be burning the leaves? Should I switch to milk? Its mild modes(right now) but have 3 weeks to go with this glorious tree I have grow
Here are 2 pics. Both of same location... One with flash and one without.
Any suggestions appreciated.

 

[Southpw]

 

[ChefDGreen]

Spray at night. Water droplets magnify light rays and burn plants.

 

[Southpw]

Thanks. I do spray at night. And location of burn is on far side of sun so likely not a reaction to the sun doing the damage.
I'm stumped. Not sure if I continue with treatment or not. I held off yesterday hoping for some responses here. I will continue the application for now.

 

[TorturedSoul]

5% Apple cider vinegar is pretty acidic (although somewhat less so than "white" (clear) vinegar). Typically, its pH is in the 3.3 to 3.5 range. I've read that it can be in the 2 to 3 range, but I'm guessing that's a product that's at a higher concentration (although that's just a guess).

What was the pH of the solution you mixed up?

 

[Southpw]

Hmmmm. I never checked ph of solution. I will do that tomorrow when I get back home. My wife is tending to the garden today and won't bother her with checking pH or spraying the leaves.
Thanks for your response