Leaves got something like a burn

Your plant is young enough that it'll be fine, but yea, as GG said, no spray with the lights on! The water acts as a magnifying glass and the leaves get burned just as we do. You can definitely foliar feed your babies (they do love it!), but do it at lights out :)

Not much you can do if you sprayed it when the lights were on... no reason to spray with water anyway, is there? If you're trying to raise the humidity in your tent, there are better ways of doing that - and if you ever have to spray with something like an insecticide, you always need to do that just before lights out... Sorry, mate.... no remedies here....