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Why Glass Fish Bowls Are Bad for Your Fish

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Finatics is a fish enthusiast and enjoys writing detailed guides on how to care for various species of aquarium fish.

Discover the reasons why a glass bowl is an inappropriate home for any fish, from a betta to a goldfish.

Discover the reasons why a glass bowl is an inappropriate home for any fish, from a betta to a goldfish.

Why a Bowl Isn't a Healthy Home for a Fish

Fish-keeping has evolved over centuries, from small vases and bowls to the high-tech aquariums of today. Unfortunately, some fish-keepers haven't advanced yet and still keep their pets in the dreaded fish bowl. Ironically, fish bowls are not suitable homes for aquarium fish, whether they're goldfish, bettas or any other animal.

The Essential Goldfish: Total Care, Housing, and Feeding Your Goldfish, Keeping Your Pet Healthy, Breeding by Maddy Hargrove says about the fish bowl, "A muddy puddle in a deep pothole would probably be better." And for many reasons:

1. The Round Shape Has a Poor Surface-to-Air Ratio

The shape of the bowl minimizes the surface-to-air ratio. This is the proportion of how much water surface is exposed to air as opposed to the rest of the water. The higher the ratio, the more oxygen will dissolve into the water, allowing the fish to breathe more easily. The rectangular form of an aquarium allows for a larger surface-to-air ratio, keeping O2 levels up.

2. It's Hard to Regulate the Bowl's Temperature

The size of the bowl makes it virtually impossible to keep a regulated temperature, as it's too small to fit a heater (unless you want an overheated tank) and the amount of water is too little for the temperature to stay the same. Also, most pet fish kept today are tropical and need a heater to keep the water warmer than room temperature. Betta fish, one of the most popular choices for a fish bowl, are an example of a warm-water fish.

This bowl is too small for a betta fish to thrive.

This bowl is too small for a betta fish to thrive.

3. It Doesn't Have Room for a Filter

The size of a fish bowl also cannot accommodate a filter. This is a huge problem because filters oxygenate water so fish can breathe, and they pick up solid waste from the water. The filter keeps the waste from decomposing and producing chemicals toxic to your fish.

4. It Doesn't Offer Fish Enough Space to Swim

No swimming room! Your fish need space to explore their surroundings, so there should be enough room for some hiding places for when they're scared and want to chill for a bit.

5. The Open Top Is Dangerous

The open top is an obvious danger for a suicidal fish—and who wouldn't be depressed if they lived in a bowl? The fish can jump out and suffocate on your living room carpet! Toxins can also fall into the water and poison them, or even a hungry cat could go fishing for his next meal.

6. The Shape of the Bowl Distorts the Fish's View

The curved glass makes the fish's view distorted, stressing out the animal. Imagine if huge blurry blobs were walking around your window every day.

These are the only fish that belong in a bowl!

These are the only fish that belong in a bowl!

Have a Heart: Buy an Aquarium

If you buy a pet, whether it's a fish or a dog, it is your responsibility to make sure s/he gets the best care possible under your ownership. Animals are not toys—they are living creatures and need to be respected and treated right. This includes fish. If you're keeping a fish in a bowl, do the right thing and buy a proper aquarium!


wayuupthere on June 14, 2019:

fish bowls are bad

I think that fish bowls are horrible if they are very low quality and no space on August 27, 2018:

They are very horrible for your

theunknownperson(mightbeaghostsorryifiamscaryingyoubutmaybe)!!! on August 17, 2018:

this hub is helpful for my ghost fishy!!!

May on October 26, 2016:

Hi, I have two small molly fishes about 2 to 3 inches and I feed them in a about 20cm x 10cm rectangular tank. May I ask is it ok for the fish ?Thanks.

May on October 26, 2016:

Hi, I have two small molly fishes about 2 to 3 inches and I feed them in a about 20cm x 10cm rectangular tank. May I ask is it ok for the fish ?Thanks.

Trevor on September 30, 2016:

I too have seen betta fish stuck in a fish bowel. Except for the swimming space problem.You can have a small pump leading outside of the tank witch than lead into a filter.That would also allow for more O2. As for the cat eating it you could have a small lid.Be ware, I am not arguing angst you but I am just stating that for people who cant afford a proper tank. But please if you do want to get a pet fish, at least get a five gallon and don't over croud the tank.The general rule of thumb is 1 inch of fish for 1 gallon of water but this does not work for all fish.

Pet on September 28, 2016:

My fish live in a 15 litre bowl with filter, a live plant and an ornament. They look happy.

Jackie on August 10, 2015:

What about gold fish? They don't have to be kept warm and I know of doctor's offices who have had them for years and they do just fine?

ra on January 05, 2015:

You must be a strict vegetarian, right? :)

Chalcedony on January 19, 2013:

It's nice that you explained all this, but as an experienced Fish tank keeper I can tell you that your video of the "happy Beta Fish" is not much better than bowl you're talking of: It is way too small for it; every fish needs at least 54 litres. In my country, the employees of the pet store will refuse to sell you any fish if you tell them, your fish tank is smaller than that.

You can also see, that fish is not happy by swimming along the glass pane; this means he is not happy at all and wants to escape his prison. And in the fish tank, there should be more (real) plants, the Beta's natural environment is a messy underwater jungle.

Please, if you keep living beings, treat them like they deserve it and in an environment, that ressembles their natural ones. Thank you.

surah on December 11, 2012:

thank you very much! i was considering to put fish in the bowl until i read ur article.. very informative... thank you!

Whyhellothere on December 01, 2012:

Does this mean that you're a vegetarian?

Camdyn on October 19, 2012:

I have had a betta in a fish bowl for almost 3 years and he seems to be doing just fine so plz tell me what is the normal lifespan of a betta fish

and also very nice job stating the importance i will try to fix my betta in a bowl if needed

NOYB on October 02, 2012:

I've had a betta last for eight years and he lived in a one gallon bowl with no heater or filter!

John on September 30, 2012:

I forgot to add I keep my male in a ten gallon he is two years old. My female is a year old in a twenty gallon community tank. I belong to senoir member choclatebetta.

John on September 30, 2012:

Bowls and aquariums are really different. A betta averages 2-3 years in a bowl 5-7 and sometimes 10 years in a heated filtered big enough tank.

NOYB on September 13, 2012:

If fishbowls should be outlawed, then so should ALL aquariums!

KZHVX on August 10, 2012:

Awesome article!

Thank you for clarifying exactly why, I will be sure to mention this to customers from now on :)

Ps Loved the Campbells fish soup part!

Cybermouse from Bentonville, AR on July 25, 2012:

Great hub! Every site that has any information at all about fish care should have this hub, or something like it, as a must-read sticky note kind of thing before you can even join the site. If more people knew about proper fish care, I don't think they'd be quite as popular as pets. Getting a small bowl with no filter is about like buying a dead fish, if you've never cared for fish before.

I find it sad and deplorable that people keep fish in bowls, or worse, tiny vases, like they're just a moving flower or something. Makes me wonder if they even feed them - how would you get the food down there without taking the plants out every time? Someone that's too lazy to get a proper tank is probably too lazy to even feed the poor fish to begin with, much less change the water frequently enough to do any good.

I was horrified last week when I learned that a coworker who was quitting and moving away had stopped feeding and changing water for his betta (presumably in hopes it would die so he didn't have to take it back with him). I immediately offered to take the betta and was surprised to find it in decent health, chugging along just fine after apparently several weeks of malnutrition and dirty water. It's a good thing they're resilient - but as you said, that's no excuse to treat them badly or provide them less attention and care than any other pet.

bettaowner on July 10, 2012:

what about a big bowl with a filter and airstone

finatics (author) on June 02, 2012:

@hannahbanana09091, yes but the difference between bettas and other fish is that they can SURVIVE in a bowl, but they will never thrive. Is that a humane choice to do to your pet?

@saha, I completely agree that it is necessary for us to respect all life.

hannahbanana09091 on November 04, 2011:

k i do agree but bettas dont need lots of air right? so its not that bad to keep bettas in bowls but any other fish is wrong in my opionion. i still kinda think its mean to keep bettas in a bowl but its not horrible...

finatics (author) on April 18, 2011:

Thank you, pldominice! It does get irritating when people don't do proper research on their pet's care. I'm glad to hear that you are helping to spread the word on fish bowl cruelty!

Patricia Dominice from Atlanta, GA on April 17, 2011:

LOVE this article!

I just wrote one about the goldfish bowl myth, haha. I work in a pet store and I get this every day and its awful to have to explain this all day long, but I'd rather do it than the alternative, of course.

finatics (author) on March 26, 2011:

Hey Paramorefan (love that band!) I would actually not recommend buying from Walmart because if you do, you support the store and allow them to replace the fish you bought with even more that will be neglected.

Paramorefan on March 23, 2011:

If you are thinking of getting a fish please get one from Walmart, they don't give them any attention and they always end up getting sick or mutated (i would know i bought a 1 eyed gold fish from them) please help those fish

finatics (author) on March 05, 2011:

You're welcome, jeannieinabottle. Unfortunately, when pet stores sell their animals in tiny, cramped quarters, it leads customers to believe it's okay, and helps propagate the myth that fish bowls are healthy ways to keep fish. The only way to stop this is if people do better research before they impulsively buy their fish.

Jeannie Marie from Baltimore, MD on March 03, 2011:

Thanks for creating this hub. It breaks my heart when I see bettas stuck in those little bowls at the pet store.

finatics (author) on January 29, 2011:

Thank you Blue_Oranda89!

Blue_Oranda89 on January 16, 2011:

Very nice hub, you did a great job!