one white spot on fantail goldfish

Question
Hi,  I have a 10 gallon tank, with one goldfish a fantail, she's small and I've had her for a year.  The water parameters are all "normal" for goldfish.  Yesterday i noticed her hanging in an opposite corner than she usually hangs in.  I started observing her and saw a (one) white spot, fairly large, which protrudes out from her scales, just behind the gill area.  She seems hungrier than usual.  The spot shape is round, slightly raised, smooth and the center area sticking out farther than the base.  That's all the info i can think of. oh, i do weekly water changes and the nitrates are about .05 and i have some small plants.  What is it and how do i treat it?
         Sincerely Jean

Answer
Hi Jean,
Its always difficult to diagnose a fish illnesses with just a few symptoms to go off of and without being able to see the fish myself. And sometimes, only a fish veterinarian would be able to properly diagnose an illness by looking at the pathogen in a sample under a microscope to determine if it is parasitic, viral, bacterial, or fungal in nature.

A picture would help but if that's not possible that's ok.

The white spot may be an injury, or a common bump that goldfish get that may or may not be a small infection. If it turns red or changes in color or size or the fish gets red streaks on its fins/body or anything else unusual you may want to start a good strong antibiotic (like those made by Mardel Brand)

But first, please read here for descriptions and diagnosing by symptoms of several types of "white spots" on goldfish-

http://thegab.org/Articles/DiagnosisChart.html#WhiteSpots

Perhaps you can determine what your goldfish has.

I do hope this helps!
Karen~