Top 16 Best Fish For 3 Gallon Tank (Updated 2023)

If you are considering an aquarium that is smaller for your office or at home the first thing you need to consider is choosing a fish that is certain to impress anyone who comes across it.

When the tank you have is just three gallons, the options are limited. But limited does not mean you have anything to pick from!

We’d like to begin this by stating that a tank of three-gallon capacity is not the ideal, permanent home to many species of fish.

We suggest a move to at minimum a five-gallon in case you’re looking for an ongoing fixture.

That said now, let’s get right into our top 16 picks for the most desirable fish to keep in a 3-gallon tank.

Top 16 Best Fish for 3 Gallon Tank

Three-gallon tanks are perfect for those who are just beginning.

If your children are just starting to explore aquariums and taking care of the fish in their aquariums, then this size is the ideal size.

Simply because a fish is smaller doesn’t mean that it isn’t as responsible, every aquarium comes with its drawbacks.

There aren’t many fish that thrive in a tank of three-gallon. After a few months, it’s best to move the fish into a bigger and more suitable habitat.

Three-gallon fish tanks are available in stores to serve a purpose.

They can be used for small tanks for breeding or sick tanks.

Be sure to give your tank suitable conditions for any fish you’ll be keeping in it and you’ll be good to go.

Let’s get to our top pics for the best fish for 3 gallon tank.

Best Fish For 3 Gallon Tank Kit
Best Fish For 3 Gallon Tank

1. Pea Puffer Fish

Name of the scientific name Carinotetraodon travancorius

This species isn’t suitable for a community tank in any way. Despite their size being just 1.25 inches, these fish could be territorial and hostile towards other fish and puffers can be difficult to maintain in a communal tank.

To ensure that they flourish within the tank, it could be beneficial to add some floating plants to ensure they can have a place to roam.

There have been reports of pea puffers escaping from their tanks, therefore, you must be wary if you plan to keep your tank open. Ideally, puffer fish require an ambient temperature of 77-79 degrees F, and they prefer a pH of around 7-7.8.

2. Bumblebee Goby

Scientific name: Brachygobius doriae

They are vividly colored fish that have stripes of yellow and black. They are freshwater fish, the fish in this species, do exceptionally well, if not better than in brackish water.

They are very active. While they’re peaceful, however, they can also be combative with each other. It is therefore recommended to only keep one goby bumblebee in the tank that is 3 gallons in size.

They can be difficult to handle since they consume a lot of food and could be overfed when they are kept with other fish. Their optimal pH is around 7.4-8.2 and their preferred temperature range is between 74-80degF.

3. Bettas

Our first pick is one that you’re likely already aware of: Bettas!

You’ve likely seen them in those small plastic containers in the supermarket.

The tiny tubes aren’t the right place to put these tubes.

Betta fish, also called Siamese Fighting Fish, are colorful, long-finned, and aggressive fish in Thailand, Cambodia, Vietnam, and Laos.

There are a variety of fin styles and colors to pick from including the Crowntail betta, veil, Delta Halfmoon, and double tail to just name some.

They are often referred to as “great starter pets.”

Bettas come with particular specifications, just like other fish.

They shouldn’t be just put in a bowl, and then be forgotten about.

Bettas can live in a tank of three-gallon size equipped with a filter and heater.

They’re tropical fish that perform well in waters that range from 75 and 82 degrees.

The temperature should be measured using the use of a thermometer.

Three-gallon tanks are ideal for bettas due to their requirement to be housed in a separate location.

Don’t fret about them becoming lonely. Bettas have a tendency to become territorial and keeping more than one in a single house can result in fights.

Should you wish to offer them a tankmate, such as snails or ghost shrimp, we’d suggest expanding the size of your tank.

In order to lead healthy, happy lives it is essential that they be able to find a permanent residence in a tank of no less than five Gallons.

Space is essential for any tank, therefore be careful not to put excessive ornaments or plastic plants in the home of your Betta.

Bettas like having space to roam and play with their friends, but too many ornaments that have sharp edges could break the fins of their mates.

It’s better to stay clear of decorating like this altogether.

Bettas are carnivores and must be fed a balanced diet consisting of either pellets or flaked food.

4. Guppies

The next fish you’ll see will be live breeding that you’ve likely encountered before.

A very sought-after fish to keep in aquariums. Guppies have been wonderful pets since the end of the 1800s.

They come in a vast range of colors, and many different types of fins and patterns available.

They’re great if you’re trying to incorporate fresh fish into your aquarium’s style.

Guppies are a different fish species that could be housed in a tank of three gallons However, just one!

For trios, the smallest tank they can be kept in is a 5-gallon tank.

Guppies can grow to about 2 inches long. Having too many in the smallest tank could result in a bad habitat for them.

Additionally, guppies can be quick to reproduce.

It’s possible to end up with more fry than you know which ones to use in the first place, particularly if they’re stored in such a tiny tank.

Guppies, just like the majority of live breeders, do better when they have pH ranges of 7.0 or greater.

They prefer warm water, at about 77 °, and they like their water hard.

They are also omnivores and consume algae that are in the tank.

They’re not picky eaters, in the most subtle of ways.

5. Least Killifish

You may have heard about this tiny fish previously.

Least Killifish are known as the world’s most tiny live breeder, and one of the largest fishes on Earth.

There’s a limit of one ounce in a three-gallon tank, but anything greater than that, you’ll require at minimum five-gallon.

They are typically found in freshwater. you could even spot them even in your backyard!

Least Killifish live in ponds and waterways that are slow, their habitat is typically filled with heavy vegetation.

They’re also quite simple to capture and bring home, even though we don’t suggest it.

Live breeders who are caught wild could bring parasites back home with them.

Least Killifish are social, playful, and playful fish that adjust to most types of water.

They’re well at room temperature between 68 and 80 degrees. They can even stand up to temperatures as lower as 50 degrees and even 90.

Another fish that is omnivorous. At Least Killifish aren’t picky eaters.

They can be fed almost every fish food you can think of, however, live fish should comprise the majority of their food intake.

Their food source is a mixture of bloodworms, mosquito larvae brine shrimp, and fruit flies with wings that are not wingless and tiny daphnia.

It’s best to feed them fresh homemade food at all times.

If not, dry and frozen food is fine.

6. Scarlet Gem

Scientific name: Dario dario

The scarlet fish is approximately 1.5 inches in length and the colors are generally stunning shades of gold and red. Although it is peaceful in its personality, it is advised to keep just one gem in your three-gallon tank since they may be aggressive against other fish belonging to that same type.

Their shyness and timidity make them a poor choice for community tanks however, your 3-gallon tank could be appropriate for them as it is ensured that they get enough food.

They do better in tanks with a lot of vegetation which gives them plenty of room to conceal. Be sure the temperature in the tank is in the range of 74-79 degrees and set a pH of 6.5-7.5.

Although a tiny aquarium can be attractive it is essential to keep in mind that it takes effort to ensure that your fish flourish and not simply endure. It is essential to have at the very least a small amount of experience with fish keeping to ensure that you make the most comfortable and stress-free environment for your adorable fish!

7. Zebra Danios

Zebra Danios are another species that can be housed in a 3-gallon tank, though the conditions are far from optimal.

Zebra Danios are one of the most sought-after freshwater fishes to keep in aquariums, judging that they’re both tough and social.

With the many color variations to provide you with a wide selection of fish, they’re perfect for tanks with themed themes.

It is recommended to have 2 gallons of water for each fish, which means you can place one fish in a 3-gallon tank.

Since Zebra Danios can be schooling fish they are extremely social.

When they are by themselves for prolonged periods They can be anxious and aggressive.

Thus, although you may utilize a three-gallon container for temporary housing, we would like to caution against storing them in a tank of three-gallon throughout their life.

Once they have established their habitat, the water they drink should be kept between 64 and 77 degrees, which is about room temperature. It should also be perhaps controlled by a heater during winter.

They prefer to have a pH between 6.0 to 8.0.

Zebra Danios are omnivorous and are fond of eating small crustaceans, mosquito larvae, algae, and worms.

They can be fed with a premium flake, or often feeding algae-based flakes as well.

8. Otocinclus

This bottom feeder could be temporarily housed in a 3-gallon tank. It feeds off algae that develop within the tank.

It is possible to house around three in a 3-gallon tank.

Otos are calm, small fishing schools that have spent much of their time on the surface, eating algae that cross their paths.

They’re also more active during the day.

Otos are thriving in cold, harder water that ranges from 72-82 degrees and a pH that is between six and 7.5

But, they’re extremely social and shouldn’t be left alone in their homes.

A few fish inside a smaller tank can be okay for a short time however, they are best placed in groups of 10 to 15 people in the 20-gallon fish tank.

Otos enjoy eating and will eat algae.

If kept in larger tanks it is recommended to feed them algae wafers or catfish pellets.

If there aren’t enough algae to feed the Otos within their tanks, you could provide them with blanched veggies.

Be sure to ensure that you secure anything you intend to feed them. Also, do not leave any vegetables in your aquarium for more than three days.

9. Ghost Shrimp

Ghost shrimps are another simple-to-care-for fish on this list.

These shrimps are tropical fish and are located in freshwater.

They are often used to catch fish as bait However, it doesn’t mean they won’t make excellent pets or tankmates.

They grow to approximately 1.5 inches long. females tend to be bigger than males.

Ghost shrimp will do just good on their own.

They can be a part of a group with other ghost shrimp however, groups are not needed.

Ghost shrimp are omnivores, and will eat whatever they’re offered, such as pellets, flakes, and algae wafers, as an example.

Because they’re hungry eaters, they’re excellent at cleaning their tanks. They devour all leftover food, algae, and plant waste that may be present in their aquariums.

10. Tetras

We’ll be next with Tetras.

Tetras are small enough that they can comfortably live in a 3-gallon tank. You could even keep more than five at once in a tiny tank!

They do well in groups that are six or more. They should be kept in 10 to 20-gallon aquariums.

They’re gorgeous thanks to their vivid colors and neon tetras are especially gorgeous.

There are numerous kinds of Tetras. Some are more suitable for those who are new than others.

If you’re beginning your fish in a three-gallon tank, it’s best to choose bloodfins or black skirts with serpaes or eyes with red.

Other types, like neons, are more difficult to maintain.

Tetras like soft water, are acidic.

In the case of most tetras, an ideal pH is in the range of 6.8 to 7.8.

Because they are located in warmer environments in the wild, the ideal temperature for Tetras is between 75-80 degrees.

There’s a small variation, however, since it is the Buenos Aires tetra that does better in cooler water!

Tetras are omnivores and do well-suited to eating either tropical flakes, tropical granules as well as shrimp pellets.

You could even offer them food that is frozen or live as treats!

11. Glofish (Glowfish)

Glofish are smaller and easy to care for fish species that were genetically engineered to emit fluorescent colors when lit by blacklight.

The glofish we suggest for a three-gallon tank includes barbs, danios, and Tetras.

Like other fish, they shouldn’t be kept for long in tanks that are three gallons or less.

Their most preferred tank size is 20-gallon.

They can be used in conjunction with other Tetras and Danios as they move into their new homes.

Glofish is another option for a tank with a three-gallon capacity.

They can grow up to approximately two inches long and they are able to live on their own.

They like temperatures ranging from 72 and 82 ° with they prefer a pH range of between 6.5 to 7.5 and intermediate water hardness.

Glofish are omnivores which means their diet must include pellets, flakes as well as freeze-dried (or frozen, or even dried in the freezer) food, although the food they consume should be thawed prior to feeding them.

They are also recommended to eat twice every day, in small portions.

12. White Cloud Minnows

The next fish is uncommon and almost extinct, but still the best fish for 3 gallon tank capacity.

Minnows of this size are schooling fish, and are best kept in a species-only tank, or in a tropical fish family.

Because they’re schooling fish they’re more comfortable living in groups.

White Cloud Minnows prefer warm temperatures around 72° with which a pH that is between 6.0 and 8.0 and they like water that is a bit harder.

Their diet includes nearly everything, that they’re omnivores.

They favor various insects, including Daphnia or mosquito larvae.

They’re also fond of shrimp.

The diet of these animals can consist of bloodworms, shrimp algae wafers, fish fry brine shrimp, and even cooked greens!

13. Endler’s Livebearer

The scientific name for this is: Poecilia Wingei

Though tiny, the Livebearer of the Endler is a stunning species. As with other true kill fishes, The Endler’s livebearer is a continuously reproducing species that produces live young, rather than producing eggs.

There is a chance that you will end up having hundreds or even thousands of livebearers If you keep fish of opposite genders together. To prevent breeding within tanks, it’s suggested that you keep just two or three endler’s livebearers of the same sex in your tank.

Males are typically smaller than females. They have an average length of one inch. Females, however, can reach 1.5 inches. They are extremely active fish that thrive in water with a pH of 7-7.5.

14. Asian Stone Catfish

This fish species originated in Asia specifically India as well as Bangladesh. Their average length is approximately 1 inch.

This catfish isn’t the ideal choice if you want a vividly colored fish since their dull colors permit them to blend perfectly with the surrounding in your aquariums. But, they compensate for the absence of color through their noticeable whiskers.

Because of their inactivity and their status as night-time animals, you will not see them often unless you’re very attentive!

While it’s not required to group them with each other, it wouldn’t be a bad idea to keep around three in your 3-gallon tank. They thrive in temperatures of 75deg-80degF as well as an average pH between 5.6-7.5.

15. Pygmy Gourami

Name of the scientific name is Trichopsis pumila

The pygmy gourami, which is one of the smaller species of the gourami family, with a mean measurement in the range of 1.5 inches. Their bodies are vibrant and appealingly colored.

Similar to the betta, gouramis are also a labyrinth-fish. They have a calm temperament and are fairly easy to take care of. It is essential to ensure the pet is kept in a calm area as they can easily be disturbed by loud sounds. They also shed their vibrant colors if they are kept in a room that is too bright, which is why you should avoid lighting too!

They thrive in temperatures ranging from the 77-83 deg F range, with a pH that is 6-7.5. It is also advisable to make sure your tank has been established.

16. Snails

Snails are an iconic addition to have in your home tanks, and chances are that you’ve seen at least one in the past.

Snails make great tank companions for a variety of species and can be kept in their own tank.

Many snails are able to reproduce sexually which means they lay eggs that will be born and release the newborn snails into your aquarium.

Three-gallon tanks are great to keep snail eggs under control.

Beware However, be aware. Snails are often avid escapers, and their tanks must be covered.

Like octopi, if there’s a way to get out of the tank, they’ll discover it.

Freshwater snails are great tank cleaners. They live on a diet of decaying plants and leftover food that is left unfinished by their tankmates.

They also consume algae wafers as well as fish flakes, and pellets along with bottom feeder tablets.

Because the requirements for care, including pH and temperature can vary from snail to It’s best to discuss with the breeder or the pet store that you bought your snail from.


What Fish Can Live Well in a 3-Gallon Tank?

In their juvenile years, many large-bodied fish species are able to be accommodated in a nano-tank. A six-month-old fancy goldfish can be just 2-inches in length but can become 6-inches tall when an adult. The nano fish that can grow only 2-inches in adulthood are great for stocking tanks of 3 gallons.

Is a 3-Gallon Tank Good for a Betta?

The betta requires more than 3 gallons of water if you would like them to be satisfied energetic, active, and responsive to you. Certain kinds of Betta fish, like that of the King Betta, cannot survive even in a 3-gallon tank. Fish owners agree that Bettas require at minimum an area of 10 gals in order to thrive.

How Big Should a Fish Tank be for 3 Fish?

The most common rule of thumb to use for determining the size of an aquarium is to utilize one gallon of water for every millimeter of fish. The rule states that for every centimeter of fish that you’d like to keep, the tank must be able to accommodate 1-gallon water.

Is a 3-Gallon Tank Too Small?

A 3-gallon tank is the smallest one available, which means it’s inexpensive and should be able to be put wherever. Small tanks have some challenges, like squeezing everything you require inside. But, they also have many more applications than just holding one or two fish.

How Long Will It Take 3-gallon Tanks to Cycle?

It could take from 6 to 8 weeks to cycle a tank of fish with fish. The method of cycling using fish is using the waste of fish to create ammonia. After you have set up the aquarium for fish and then added fish you’ll feed the fish after which the fish will create waste within the tank.


In actuality, a 3-gallon tank could be more difficult to maintain than a bigger one due to a range of reasons.

The first thing to note is that a 3-gallon tank is very small, and this is why it is prone to sudden fluctuations in temperature or quality of water. Therefore, it is important to be vigilant about your tank to ensure you are able to spot any changes in the parameters of your water.

Also, you could underestimate the amount of bioload produced by these tiny fish. They are small, therefore they won’t generate any bioload of significant size, right?

This isn’t the case in any way. Even in the event that the bioload created isn’t significant, it could nevertheless quickly rise to levels that can cause harm to the fish you are feeding.

It is necessary to remove the water from the system (a sponge filter can do it) to decrease the risk of these bioloads destroying the water, and ultimately straining your fish.

Thirdly, you must change a minimum of 25% of the water each week, to ensure that the quality of water in your tank remains at a satisfactory level.

In the end, it is important to incorporate some floating plants or any other plant, in your tank to give your fish something to look at, and a place to go.

What is your fish’s performance in their tank of three-gallon size?

What type of best fish for 3 gallon tank would you suggest for novices?

We’d love to hear from you via the comment section below. We’d be delighted to hear from you.


Dibyajyoti Bordoloi is the creator and author of, a third-generation experienced fish keeper and owner of a successful pet breeding farm. He is also a member of the Center for Wildlife Rehabilitation And Conservation (Assam), the Marine Aquarium Societies of North East India, and the Kaziranga Nature Conservancy of Assam.