Guppy tails

Question
I got a new guppy from a friend who moved to Texas.  It was a beautiful fish with a bright organge fan tail. My small tank set up was brand new (I got it for the new fish) I also added another guppy and some neon tetras with a small bottom feeder. Within a week, the guppy's tail began to fray.  It eventually went away all together then grew back but it seems to be smaller, though uniform.  I don't know anything about fish.  What happened?

Answer
Hi Suzie:  The tail degeneration is quite possibly stress... or even water chemistry or a change in diet.  The tail should regenerate to its old glory with time.  How large is your tank and how often do you change water???  Do you check the water chemistry??? dave