Ever since I got her (from Walmart. I know, enough said...) she has had a twist in her tail fin, however, as of today, it's gotten red and possibly infected? Here are some pictures, I don't know how to treat her.. 
http://img.photobucket.com/albums/v356/chica4Christ8/IMG_0372.jpg
http://img.photobucket.com/albums/v356/chica4Christ8/IMG_0370.jpg
http://img.photobucket.com/albums/v356/chica4Christ8/IMG_0369.jpg
http://img.photobucket.com/albums/v356/chica4Christ8/IMG_0372.jpg
http://img.photobucket.com/albums/v356/chica4Christ8/IMG_0370.jpg
http://img.photobucket.com/albums/v356/chica4Christ8/IMG_0369.jpg