Well, I don't see any bugs.

Take a close look at the spots.
First, try brushing them off. (long shot)
Do they look like some of the leaf has been eaten.
Thrips make those kine marks on the tops of leaves by noshing on the top layer.

If the surface is level, look on the bottom of the leaf with a magnifying glass.
Any eggs, poo, webbing?
No?

Dang!
So much for easy.
I don't like the looks of those fan leaves in the background.
It would be a good move to take some better snaps and fill out the troubleshooting form.

http://boards.cannabis.com/plant-problems/127058-troubleshooting-form-yay-you-know-you-wanted-one.html

We have some real talent here, but you have to help them help you.

Aloha,
Wee 'zard