Goldfish changing colour

Question
Hi Nathan,
After two years one of my pond fish is developing black scales. The other one I have is it's original gold. They both appear very healthy! Any idea why this change has occurred?

Answer
Hi Tony,

The fact that only one goldfish is sick is rather strange Black spots are usually caused from a high level of ammonia in your pond. The black spots are signs that the fish are recovering. The black spots should go away after two weeks or so. Do a 10-20% water change, and that will help the fish recover.

Good Luck, and I hope your fish recover!