I've noticed one of my female guppies has been slowly but surely losing her tail. I have a lot of very young guppies in the tank and they are very playful, so its not unusual to find nipped tails (although usually on the boys). However, because it looks like a little more is being "nipped" each day" I am a little concerned. Can someone tell me how I can best figure out if this is just the usual nipping or if there is some sort of fin rot going on? For the time being I have separated her out, figuring that whether she is being bullied or is ill a little time out wouldn't hurt.