My first Auto

This looks like little burn spots. Are you misting them with the lights on? Those LEDs put out a crazy amount of power and they look pretty close to the plants. I run my LEDs full power but always keep them at least 36 inches from the plants. If you mist them or spill nutrients on them then the light magnifies the droplets and can burn the plants. I am personally anti-foliar feeding. There really isn't much benefit of spraying your plants as long as you have good quality nutrients and an adequate grow medium. The roots do a great job if they are healthy. Raising your lights higher, feeding your roots properly, and making sure you are in range on pH will improve the happiness of your plants 100%. I would also check the plants closely for tiny insect pest with a magnifying glass just to be on the safe side. They usually attack the lower side of the leaves. Little bugs can cause similar damage. Good luck with your grow!