hey there Joint Operation. the good news is that you did the right thing. That's calmag deficiency from too much light, and if you've already reduced the light cycle / intensity you've treated the root cause of the problem . Plants need more calmag with a lot of light , it's that simple. Add more calmag if you're nervous, but the problem should have already stopped spreading and the plants already started to recover. Just be aware of this going forward, if you blast them again, up the calmag, make a spray with calmag, that sort of thing. Hope this helps ! π