I get this question a lot:
“Can goldfish live in a bowl?”
Well, I’m going to shock you by saying this:
Goldfish bowls are not always evil.
There. I said it.
Today I’m going to talk about the RIGHT way to use a bowl for your fish…
… And also how to avoid the problems most people have using them.
Are you ready?
There is a way you can get that little fish to live in an “undersized” bowl for longer than a few weeks.
It actually IS possible to have:
- Sufficient oxygen exchange
- Acceptable water quality
- Enough bacteria to establish a “cycled” state and reduce the need for water changes
Set your bowl up properly to begin with and you can have a pet that brings you enjoyment for years to come!
Yes, Goldfish CAN Live in a Bowl
You may have been told that fish bowls make terrible homes for goldfish.
There is a nugget of truth to that.
They CAN – but the problem isn’t the bowl, but the poor conditions inside it.
Big tanks can be just as deadly to goldfish with poor living conditions.
But there IS a way the bowl can be made into a safe environment.
When set up and maintained properly, your fish can live a long, healthy life – maybe even outliving the family dog.
(And those of you who are 100% anti-fishbowl, please hear me completely out before you give me the heat. I used to be too, but there are two sides to every story. My goal is to give a logical, balanced view of things as best as I can. )
5 myths people have about bowls:
1. Goldfish Get too Huge to Live in a Bowl
It’s very true:
Goldfish can grow to be really big, given certain genetic factors and living conditions.
But goldfish also have the ability to regulate their growth in a small space.
While a full-grown Common goldfish might get to be 12″ in a pond with tons of fresh water and room to swim…
That same fish won’t get bigger than 3-5″ in a bowl, even after many years (provided the water is not constantly changed).
Such a fish is said to be “stunted.”
(More on exactly what causes stunting later.)
So in a sense, the old saying is true…
…A goldfish CAN grow to the size of its home.
2. Bowls are Impossible to Keep Clean
This is a common myth.
When the bowl is equipped with a proper filter and a substrate that supplies enough surface area for beneficial bacteria to grow, a bowl can house a colony of nitrifying bacteria that keep the parameters within safe levels between water changes.
An undergravel bowl filter also supplies oxygen to the water, preventing anoxia.
Besides all that, plants can be added to help absorb excess nutrients.
People who have difficulties keeping bowls clean usually have no filter and/or are overfeeding.
As long as you follow our guide on setup, keeping your bowl clean for your fish is easier than ever.
It’s also best to go with something like a large plastic goldfish bowl – to help keep the water cleaner.
3. There isn’t enough Oxygen for the Fish to Breathe
It used to be that lots of plants and frequent water changes were the only ways to keep the oxygen levels high enough in a bowl.
This a problem modern filtration has really helped to overcome.
An undergravel bowl filter creates constant surface agitation and water movement, allowing gas exchange to take place around the clock.
Even with a very small surface area, provided the temperatures are not too warm, a filter is probably the best way to keep the water full of oxygen for your fish (and a few extra plants won’t hurt for an extra boost!).
4. It is Harmful to Stunt a Fish’s Growth
Yes, fish kept in smaller enclosures are often stunted (though not from the enclosure itself, but from the more concentrated growth inhibiting hormones).
The question is…
Is it cruel due to causing harm to the health of the goldfish?
My take on this is no, and I wrote a whole new post about it you can read here.
5. Goldfish Won’t Live Long in a Bowl
Given the right care, a goldfish can actually live several decades in a bowl.
Can… and have.
Sadly, most people aren’t told how to set up and care for a goldfish bowl properly, and consequently their fish don’t last more than a year (unless they just happen to get an invincible fish).
The typical range is probably somewhere around 5-10 years.
Their lifespan can even be longer than those who are grown quickly in a larger environment.
6. Bowls are Cruel Because of their Smaller Size
I get it:
Surviving does not always mean thriving.
Obviously, poor care can cause a bowl to become a “torture chamber” for a fish as it remains alive while suffering from oxygen deprivation, ammonia poisoning or stunting.
But the same is true of big tanks.
Is it just cruel to keep a goldfish in a bowl, regardless of having all of its basic needs met, correct living conditions and behavioral stimulation – just because it’s in something smaller than a tank?
By definition, something that is “cruel” intentionally causes pain, harm or suffering to the animal.
So if it’s true that proper care can make bowls a safe place for goldfish that does not cause them harm – they can’t be considered cruel.
So far, all the arguments I’ve heard aren’t grounded on facts – just that person’s personal opinion and feelings.
Who is really able to determine what constitutes as “too small?”
(Provided the fish has sufficient swimming room to prevent muscle atrophy, of course.)
The term small is subjective, considering…
… Even a 40 gallon aquarium is small in comparison to a lake or river that contains thousands of gallons (a fish’s natural habitat).
If it comes back to what’s natural for the fish, then no goldfish could be kept in captivity!
There’s no doubt about it:
Goldfish keeping takes work.
It requires responsibility, attention and care.
As far as I can see:
That tanks are better than bowls when proper husbandry is implemented still remains an opinion, and not substantiated by fact.
Fish Bowls through History
It’s been done by many goldfish owners in recent times, and even in ancient times – from Japanese goldfish breeders trying to groom their ideal Tosakin, to the Victorians with their “goldfish globes.”
There are even records of goldfish that were kept in bowls living seven years and upwards, while continuing to grow normally.
Now, if they could do that back then with such success, why can’t we do it now – or even BETTER?
NOW we have the convenience of advancements of filtration technology at our back, which greatly helps to fight against the problem of rapid oxygen depletion and poor water quality – making it less work than ever before.
We have test kits we can use to closely monitor the conditions in the tank.
We have equipment that does most of the work for us – even to the point of feeding our own fish so we don’t have to remember!
They also understood the importance of controlled feeding. Some historical sources recommend twice weekly feeding of a few small earthworms or a few ant eggs once a day. This means a lower ammonia output.
They also changed the water at least once daily.
And the importance of plants was understood – especially important when they didn’t have access to modern filtration methods.
“Hence the reason why we can not keep fish any length of time in an ornamental basin or in any piece of water where there are not vegetables [plants] growing.”
It wasn’t until recent times that fish bowls have become widely socially unacceptable.
This quote from 1898 is interesting:
“We want to say a word in favor of the much abused round fish globes. It is difficult to find any book on the subject which does not condemn these globes, but the leading book on the subject now on the market is published by a manufacturer of square aquariums. It is easy to see why he should hunt for objections to the round globes; the statements in other books on the subject are apparently copied from the first one.” (Source)
The book goes on to caution readers against the abuse of the fish bowl, such as using too small of a bowl (they recommended at least 10″ in diameter).
Thoughts on Fish Size
As a good general rule of thumb (though by no means a hard-n’-fast rule), the bowl should be at least twice the length of the fish’s full-grown body to allow for comfortable swimming (the Japanese have used this ratio). A 10-inch bowl is a good starting point.
Some also use the 1 gallon per goldfish rule.
There are exceptions to this, depending largely on the fish’s genetics.
Of course, many of these fancier breeds are more delicate, making close attention to water quality very important.
But in all reality, most fancy pet store goldfish don’t get that big, even under the best of circumstances.
They are just genetically small.
The fish that show the most potential to get large are separated from their siblings and given special care before being sold to the pet store – they will command a higher price.
Wrapping it All Up
I hope you found this post insightful.
Want to share your experience or opinion?
Maybe you disagree with me?
Either way, please leave your feedback in the comments below.