I got a new light and I left it on a very low setting last night but none of my fish in this tank are used to having a light above them and on. And I think this caused Hewbie to see his reflection all night and he chased it and it caused an injury. I only left it on because they’ve been in the complete dark most the day previously and figured they’d appreciate a little light since it’s the basement. I plan to monitor and possibly treat it but I’m not sure with what. I turned the lights off and I hope it doesn’t get worse. What can I treat it with? Does it look like an injury from rubbing against the glass? The only other fish are an angel, tang, and a wrasse who I suppose could be one of the culprits. Thoughts? He seemed stressed for some reason and was glass surfing a lot more today I noticed. As mentioned I can only suspect the light/his reflection as I turned it off and he stopped chasing himself. @Jay Hemdal