Can Betta Fish Live In A Jar? (You might be surprised!)

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Betta fish have grown in popularity over the last 20 years.  Every year they are sold in their millions worldwide. On countless occasions on social media, we see images of Betta fish being kept in tiny containers.  Here I answer the question Can Bettas be kept in jars?

A jar is far too small to keep a Betta fish in.  Jars may only contain as little as 1 gallon (3.75 liters) of water which is not enough space for a Betta to swim in. The volume of water in a jar is also too small to maintain stable water parameters meaning the temperature will fluctuate too much during the day.

Can A Betta Live in a Jar?​

A jar, even a large jar, will only contain a relatively small amount of water. The jar may only hold as little as 1 gallon (3.75 liters).  Unfortunately, that simply isn’t enough water volume to provide a stable environment for a Betta fish to live in.

Not only do Betta fish need some space to swim, but they also need to live in an environment where the water is clean, has stable water parameters and the temperature doesn’t fluctuate.

The water temperature in a jar will vary massively over the course of a day and temperature swings will have a detrimental effect on a Bettas health. Bettas that are kept in unstable water are known to suffer from common diseases like Ich (whitespot)

Bettas are generally hardy, but no Betta will live for very long if it has to live in just 1 gallon of water.

It is essential that Bettas are kept in water that is clean and free from waste.

How to Keep a Bettas Water Clean?​

Whatever size tank you choose for a Betta to live in, it MUST have a filter to keep the water clean and safe for the Betta.

When a Betta goes to the bathroom, its waste is high in ammonia.  Ammonia is extremely toxic to fish and, even at relatively low levels, can kill a Betta very quickly.

An aquarium filter’s job is to take the waste from the Betta and convert it through a process known as the Nitrogen Cycle.  

The nitrogen cycle utilizes beneficial bacteria to convert the ammonia in the Bettas waste first to the less toxic nitrite, then again to the less toxic still nitrate.

Without a filter, the water the Betta lives in will quickly turn toxic and kill the Betta.

Can You Keep A Betta Without A Filter?​

Keeping a Betta without a filter is like a person living in a house without a toilet.  Without a filter, there is no way for the Bettas waste to be processed from very toxic ammonia to less harmful nitrate.

Keeping any fish in a tank without a filter would require the fishkeeper to change large volumes of water every single day, without fail.

Without appropriate filtration, the Bettas water parameters would swing wildly, causing real stress to the Betta.

What Are Betta Water Parameters and How Do You Keep Them Stable?​

When fishkeepers talk about water parameters they are usually referring to the pH and water hardness, as well as ammonia, nitrite, and nitrate.

No matter what fish we are keeping, the larger the water volume, the easier it is to maintain the water parameters.  Essentially, it is easier to keep the water parameters stable in 500 gallons than it is in 5 gallons!

For the sake of not letting this article become a science lesson, let’s assume pH and hardness won’t change much over time no matter the size of the Bettas tank. 

Ammonia, nitrite, and nitrate can swing wildly in smaller volumes of water.   If a Betta goes to the bathroom in a jar or in a large aquarium, needless to say in the large aquarium the waste will be diluted far more than in the jar.

What Size Aquarium Should A Betta Live In? ​

Minimum Betta tank size is probably the most hotly debated topic in the whole of Betta keeping.

Based on 20 years of experience of Betta keeping and 30 years of fish keeping overall, I would say for a new fish keeper, 10 gallons (38 liters) would be the minimum size aquarium for a Betta.  More experienced keepers who understand the nitrogen cycle and the consequences of overfeeding and carrying out regular water changes etc can probably get away with a 5 gallon (19 liters).

Personally, I don’t keep my Bettas in anything less than 5 gallons and the majority of my Bettas are in 10 gallons or larger.

My Final Thoughts on Keeping Betta Fish In A Jar​

A jar is simply too small to keep a Betta fish in.  A jar can’t have a filter or a heater meaning the water temperature can swing wildly during the day, and without a filter, there is no way to process the Bettas waste.

Keeping a Betta in a jar is sentencing the Betta to a slow, painful death by poisoning it with its own waste.

About the Author

I’ve been keeping, breeding, and showing tropical fish for nearly 30 years. Over that time I’ve done it all! I’ve had great success and I’ve made some really foolish mistakes (like the time I bought an Asain Walking Catfish). Read more…
Richard James

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