Goldfish black all over.

Question
I have a cross bread goldfish in a tank (5 gallons). Before, it was in a fish bowl and got ammonia burns. Now the tank is replaced to the tank. It doesn't look good for more than a week. I hadn't since the burns. The blackness had spread throughout its body. Now it had a dull blackness(in its fins &body). 85% water changers (tap water is kept for 24 hours to settle chlorine) are done everyday(or every other day) and an air pump is there. It hadn't eaten much(there are some plants in the tank which it might feed on- I'm not sure) Its belly is not flat but round(not huge). Today i saw that tip of its bottom tail fin has whitened, transparent and damaged. The ammonia dark patches are still there. I checked the water for ammonia and chlorine but they were fine levels. Its alone in the tank, often scared and stays in a corner (very lethargic). Body is covered in darkness (not black spots but simple splotches-more like suit/ash) They don't look like fungus(they don't come out of the scales).
I add a pinch of salt after every water change; there is no filter.
Reply soon Thanks Km

Answer
Hi Km,
  Unfortunately I have very little experience with goldfish and I have never seen what you describe so I can't really suggest anything.  Doing the water changes is a good idea.   You really should have a filter in the tank.  

-- Ron
  rcoleman@cichlidresearch.com
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