I guess my Tigers are setting up their pecking order right now but I see one of my Tiger Barbs has had the middle portion of their Tailfin nipped away and a piece of their dorsal fin also. He was hiding in a corner so I wanted to see what is wrong with him. Water quality is perfect (NH3 = 0, NO2 = 0, NO3 < 20) should I let them sort things out and wait for the fin to grow back or must I do something else special?