I used to have a fish tank and stored goldfish. The problem with it was that I had to keep cleaning the tank about at least once a month when chlorine made the water too dirty. Some people may argue that goldfish may not be worth taking care of because they only last a few months. I finally came to that conclusion that goldfish isn't going to be my pet anymore when they died. RIP fish!
For these goldfish, the tank was a bit too small.
Do you own a goldfish as a pet?