split tail goldfish sick

Question
i have a goldfish that has been sitting at the bottom of tank and is breathing heavy not eating..her sibling died all of a sudden couple of days ago..its a 5 gallon tank with other fish and the water was cleaned on friday we only use spring water no tap..i dont want it to die too i have other fish in there but she is the only one at the bottom

Answer
Hi Lela;

The tank is just too small for goldfish to stay healthy. Goldfish need 10 gallons just for one to thrive. They create so much waste that they can't get enough oxygen if there are more than that. It causes them to be weak and get very sick. I'm afraid you may lose more of them if you don't get them a bigger tank. Change 25% of the water every day for a few days to help her recover a bit. Also add bubbles to help with the oxygen level. This is only a temporary fix though. Shop for a bigger tank with a good filter so they all have enough room and enough oxygen. Here is a web page about what goldfish need;

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

I hope she feels better soon...

At Your Service;
Chris Robbins