RQS - Northern Light & Purple Queen

The purple queen is looking pretty healthy so no worries there, I wonder if its growing slower than it should or maybe I'm just being impatient. The northern lights hasn't developed as well, but not sure if this is normal or not. The leaves don't look as healthy green and it has developed some small black/dark brown spots on the first jagged leaves. Should I be worried? I haven't added any nutrients yet or watered them either. Do you think a I should start watering at half strength nutrients or would you say they are a bit too young still?