Goldfish is turning black

Question
We have one goldfish- we have had him since July.  We have a 2 gallon take with a filter system.  We have not had any problems so far. We change the water once a week and clean everything.  My question is why is the fish turning black and what can we do?

Answer
Hi KC;

Your goldfish needs a bigger tank. The black is from ammonia burns caused by his waste. Goldfish are so messy that they need plenty of space with good filtration. It's a myth that they can live in small tanks and bowls. I'm so sorry you were misinformed about what goldfish need. Let's see what we can do to get him in happier, healthier condition;

Get him a tank that is at least 5 gallons. Make sure it has a good filter, such as the overflow power type. He will need a 10 gallon (at least) eventually, so if you can do it and have the space/money, get a 10 gallon. If you want him to have a friend to pal around with, get a 20 gallon or larger.

In his new tank, change 25% of his water once a week, don't overfeed and he should do just fine. If you can't get him a larger tank soon, change 25% of his little tank water at least every other day. It will help keep ammonia low so it doesn't hurt him quite as much. It isn't a permanent solution though. It's only temporary so you will have a week or two to shop for a larger tank. Once the problem is solved, the black will eventually fade over the coming weeks. It is damaged tissue that needs to regenerate.

Here is a good web page about goldfish and their needs;

http://www.firsttankguide.net/goldfish.php

Good luck and I hope it goes well...

At Your Service;
Chris Robbins