I got my first Betta a month ago and recently he's been nipping his own fins. I have ordered more plants and will be getting some snails to divert his attention. Last night I noticed that he has a noticeable tear in his left pectoral,but I don't know how it could have happened. His appetite is great,but he does seem less active lately . He's in a twelve gallon planted and filtered tank. Please help, I am so worried. Will he grow it back?