the yellowing leaf i am not concerned about just low nitrogen, you can pick this off the plant now if you like. the damage on the other leaves could this be from over spray while watering? have you examined the undersides of the leaves for pests?
here is a nutrient availability chart
here is a leaf deficiency chart
here is the Cannabis Plant and Pest Problem Solver
Cannabis Plant and Pest Problem Solver - Pictorial
here is a nutrient availability chart
here is a leaf deficiency chart
here is the Cannabis Plant and Pest Problem Solver
Cannabis Plant and Pest Problem Solver - Pictorial