Fantail has black face

Question
QUESTION: I bought a Goldfish from Walmart (Yeah, I know) and fell in love.  Then his
face began to turn black and I thought it was because he was constantly
gulping air and the air was causing the spot to grow.  Then his yawning and
gulping got worse and the spot got bigger.  I looked it up and his symptoms
kind of matched flukes and ammonia burn.  I gave him parasite meds and put
him in a filtered tank.  I've been researching it like crazy but I can't find an
absolute answer.  His gulping and yawning have decreased, but the spot
remains.  It's just one big spot right between his eyes. He also gets excited
when I put my face up to the tank, he basically swims rapidly.  His appetite is
fine.  My guess is either flukes, ammonia healing, or it's just a color spot that
developed.  What is the spot? What is wrong with my fish?  Please help, I've
gotten attached to Sunshine! That's his name.


ANSWER: Hi Ella,
I think it's  just color but to make sure, what are the tank stats? (water chem, size tankmates etc.)

thanks.
-Will

---------- FOLLOW-UP ----------

QUESTION: I don't really know because I haven't bought water testing strips, but he is in a 2.5 gallon tank with a filter.  I also put water conditioning liquid in it to stablize the ammonia/chlorine levels.  If it's a color spot why would he still be gulping and yawning?  
Thanks,
Ella

Answer
Hi Ella,
Goldfish are actually large, messy fish. they can get up to 10" and shouldn't live long term in smaller than a 20 gallon tank due to their size and waste production. The black should be a sign of deteriorating water qualities. For the time being, Do a good water change and use de-chlorinator. Be sure to keep the tank very clean.

-Will