I'm not sure if 100% of 450 Watts at 13 inches is too much necessarily for your plant's stage. I might try it with my light, but that's a 300 Watt TSW 2000. The reason I brought it up is because the leaf you showed seemed a little bleachy and crispy to me. Maybe it would help people diagnose your issue better if they could see a photograph of your entire plant. Is that something you might be able to provide?