Quite often we get new members coming onto the forum constantly asking about why their fancy goldfish
(will be refered to simply as a goldfish
for the rest of the post) is doing poorly in their 1 or 2 gallon bowl. We tend to give the same spiel.
The spiel being:
that they need at least a 20 gallon long tank and preferably a 30 gallon tank for one goldfish. If you want more than one goldfish per tank add 10 - 15 gallons of water per extra fish (if you want 2 fish get minimally a 40 gallon tank for three get a 50 gallon etc . . . ).
Then we explain why a small bowl is not suitable:
Contrary to popular belief the idea that goldfish only grow to the size of their bowl or tank is only half true. Yes their body will only grow to the size of the tank/bowl, but their internal organs continue to grow causing a slow and painful death for the fish.
We also will go into detail that goldfish love to poop and that overfiltration is necessary for them.
Well I just wanted to post a picture of the size goldfish can get to when properly taken care of so that it may help any newcomers or ill informed people (due to advice a fish store gave you), just so they can see the potential of how great looking goldfish can be and to try and help get them into a proper tank or even a pond (pond if it is a Koi/common goldfish and possibly the fancy variety if it is a fancy only pond and the temperature is well managed).
Also please for anyone new to the forum, this is not to discourage you or berate you. I want (and I am sure everyone on the forum) you to be successful in your endeavors. However, sometimes we may provide information that you do not want to hear. Please just be aware not only do we want you to have a lot of success in the hobby, but we also want all fish to have the best possible life in an aquarium setting. To do this sometimes it means recommending something that is different than what the guy at the store says.
Anyway I hope this information and picture was helpful and good luck with any and all aquarium endeavors.
Here is a list of some of the various types of fancy goldfish.
All are the same species and their scientific name is Carassius auratus.