brown spots on my plants. help!

I just got 5 new clones and one out of the five has brown spots on it and i also have a plant that started from seed and is about six weeks old and has a few brown spots on it similar to the clones. i use fox farm organic nutes, grow big and fox farm organic soil. here are some pics help!

Don't worry too much. It kind of looks like it got burned by a floro light. i don't know. Maybe add some Mg to it or leave is alone, rip it off. I will be no big deal

well these plants are outdoor btw