Hi reefers! Yesterday I just noticed that my blue hippo tang has as brown spot with a little of blood in it, he’s in my 10g qt tank with two other clownfish, the tank was dosed with copper power, I made sure the levels were always correct, scared that it might be the copper, I just made a 50% water change to see if it gets better. Please let me know what it could be, as far as my research it points me to HLLE but i don’t know if it might be a simple scratch and I’m just worring for nothing. If it is somehing worrying for the fish please let me know what it could be and the best course of action, he still is as active and eating as much as ever, no shifts in behaviour.