unhealthy leaves--yellowed with spots

Here is a picture of my 6-wk old, soil-grown, cfl bagseed plant. Looking okay. I do plan to get more light on them. This is the more sativa-like one, and the rest are more squat, wider, darker leaves, seemingly more indica. I think they're doing okay.

So is this a potassium defficiency, maybe?

Thanks yall.

Dray

How 'bout I post that pic?/Users/admin/Desktop/IMG_2367.JPG