Flesh disappearing

Question
I have 2 goldfish that I rescued from an overcrowded and filthy tank in a hospital waiting room. I have had them for over 3 weeks, I started them in the tank right away because I filled most of my tank with water from my already established healthy 50g jack dempsey tank. When I brought the 2 goldies home both had tail rot and one had mouth rot. The other had a large white bump on the bottom of its abdomen I suspected maybe a parasite, but I don't know. I treated both with melafix, stress coat...etc. The tail rot and mouth rot are gone. BUT the poor fish with the white bump has been disappearing where the white bump was gradually every day. I really don't think I can save it at this point I may have like 2 days left but if there is anything I can do I will. Please help I don't know what to do!

Answer
Hi Megan;

Poor guys. Good for you for saving them!

Fish are amazingly resilient. The area of tissue loss is probably just a sloughing off of dead (necrotic) tissue. For a week or so, make a 25% water change every day in the tank. This will help keep the water clean to encourage more tissue regeneration and help inhibit infection.

The tank will be going through a break-in period too if it wasn't already set up and fully through the break-in before hand. Water from the established tank will not help them because the beneficial bacteria needed to cycle a tank is not in the water itself. It is in the gravel, filter and on decorations. Get a cup or two of the gravel from your dempsey tank and sprinkle it on the gravel in your goldfish tank. This will "seed" the new tank and help it break-in less severely. The water changes will also help keep break-in toxins tolerable. Here is more about the break-in and a good page on goldfish and their needs;

http://www.xanga.com/Expert_Fish_Help
http://www.firsttankguide.net/goldfish.php

Good luck and keep up the good work!

At Your Service;
Chris Robbins