Could be the start of nitrogen or magnesium problems, but don't change anything yet! It's only 2 leaves, to get a accurate diagnosis, it would have to be more advanced and it may not actually even be a problem. Nice to see you're paying attention though!
I've got some rusty splotches on leaves, I am thinking possibly a Cal-Mag deficiency. Any help appreciated. Will be addressing the issue tomorrow. Not from watering as I water direct on soil.
@Tweezer, thanks! 👊 With being my first grow, I am super excited and quite stressed to see results. I will be using Advanced Nutrients Sensi Coco Grow and Bloom. Along with Big Bud to finish.