I got a rbp (about 2 inch) and added him with my other 3 p's. They are all the same size. The place I got him from had other p's in there and some had sides of their gills chewed off. I asked if that was from the p's and not from a disease, and the lady said they chew on each other sometimes. So this morning, I got up and noticed that one of my p's gills is puffy, like I can see all the red stuff underneath when I see a profile view. It also looks like there my be a little slime covering over where it is irritated. Also two of my p's have bites taken out of their red fin on their bellies. I usually feed them twice a day and only fed them once yesterday. I am just hoping that this gill problem gets better and not worse. Also my tank is just now clearing up from its first cycle (I think it was the cycle). I do a 20 percent water change every Saturday. I think my tank may have nitrite or nitrate spikes, the fish are very darty when they eat. But the rest of the time they relaxe and just swim leisurely. Any imput would be appreciated. Thanx!