cleaning the smell out of the tank

Question
I have a 10 gallon tank with two large goldfish in it. We've had it for about a month and a half. We just cleaned the tank and everything in it completely yesterday (and put the fish in another bowl) Already today it has a skunky smell to it. What are we doing wrong? These fish seem to smell up the aquarium within a day or two of cleaning. Is it the food?  Thanks for any help!  

Answer
Hi Karen;

It's just too small for them and it hasn't been able to balance properly. Just one goldfish needs a ten gallon by itself because they are so messy. Ammonia rises from fish waste and their own respiration and causes the ugly smell. It hasn't been able to balance it's beneficial bacteria because it's so overcrowded. Also, every time you overclean the tank it kills that bacteria and has to try to re-establish the bacteria balance. So essentially, the tank has always been in the beginning stages of a break-in period. It can be smelly and is very hard on the fish.

Here is more about the break-in from my own web page and another about goldfish and their needs;

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

I hope things get better soon......

At Your Service;
Chris Robbins