White spots on my plants: Magnesium deficiency or spider mites?

[GrowCannabis]

I've noticed some of my plants have white spots appearing on them and was wondering what the likely causes were...heres some pictures

 

[JJ Bones]

Kind of hard to tell with these blurry pics, however it might look like some PM. Not sure though...if you think spider-mites, try looking on the bottom-side of the leaves with a scope.

 

[Grinch420]

How can i fix this same problem? What can i do?

 

[McCrackin]

Baskets that drain. Then transplant. Then add no nuts until the nut burn goes away, look at pest control through SNs. Or Bayer.

Kelp flush.
Then don't overdue it.

 

[420 Girl]

If you think it may be spider mites, I would suggest trying this:
SNS 217 Mite Spray

 

[popcrnchicken]

Don’t just think or assume and jump the gun. Get a 120x microscope and look at the leaf, if there are trail marks then u got notes if not I wouldn’t worry so much. You are growing outdoor and your plant is a eco system or soon will be. I am not an experience grower at all, but it seems you need a good rain storm. It solved my problem.