I think it sounds like you may have sprayed some water on the plants while the lights were on? That causes yellow spots to form, that later turn brown. I just did my first grow on another forum. I experienced that issue. Always do a foliar feeding before your lights normally turn out. What I do is if I need to do a foliar spray of any type, I turn all the lights off, and plug in a 400w mh bulb for the duration. I think your plant looks good.