Best 3 Gallon Fish Tanks (Setup Ideas, Equipment, Stocking and More)

There are lots of different fish tanks on the market, making it hard to pick the one that is right for you. Perhaps the first question you should be thinking is “what size tank do I need?”

A 3 gallon tank is one of the smallest available, so it’s cheap and you should be able to fit it anywhere.

Small tanks come with their own challenges though, such as squeezing everything you need inside. However, they have more uses than simply holding a few fish.

This guide reviews the best 3 gallon fish tanks available on the market, as well as how to set one up, stocking suggestions and much more…

3 Gallon Fish Tanks 101 (Overview)

Generally, the bigger the tank, the healthier your fish will be. This means that getting a 3 gallon tank can lead to problems since it’s so small.

There are not many fish that can be kept in a 3 gallon tank, but there are some.

Many new fish keepers assume that a smaller tank will be easier to look after and maintain when the opposite is actually true.

Pollutants can rapidly build up in smaller tanks because there is a lower volume of water for them to diffuse into. More time and effort will need to be put into making sure the water, and tank as a whole, stays clean.

Typical dimensions will be around 12″ x 6″ x 8″. This will weigh 3lb when empty and 27lb when full, but these numbers can very slightly between tanks.

An aquarium this small and light can be placed on most surfaces but check that your surface is large and sturdy enough to comfortably hold it when filled with water, decorations and fish.

The Best 3 Gallon Fish Tanks Reviewed

3 Gallon Starter Kit

The Tetra Aquarium
The Tetra Aquarium

Ideal for both starters and experts alike, this tank is ideal for small tropical fish.

Check On Amazon

This Tetra aquarium makes an ideal starter tank for children, students, families and even offices.

It comes with a Whisper power filter and cartridge, a pedestal base to rest the tank on, and LED lighting.

The cube shaped tank is sleek and stylish, providing a panoramic view of the fish in the tank.

Both the tank and the cover are made from durable plastic that is resistant to cracking and shattering – another reason it’s so perfect for children and families.

  • You can adjust the flow of the filter.
  • This is a quality nano tank.
  • Tank has a small footprint, so can be placed anywhere.
  • A great value starter kit.
  • You will need a heater if you want tropical fish.
  • The filter takes a while to work efficiently.
  • It is made from acrylic, so can scratch easily.

Check On Amazon

Best Quality 3 Gallon Fish Tank

MarineLand Aquarium Kit
MarineLand Aquarium Kit

This stylish aquarium looks great wherever you place it and is perfect for both beginners and advanced aquarists.

Check On Amazon

This MarineLand glass aquarium is a cube shaped, unique tank which has a rail light across the top. The lighting has both daylight and moonlight LED settings. The white lights create a light on the water which mimics the sun, and the blue light produces a moonlight glow.

It has either a hinged, or a sliding glass canopy which allows you to access the tank and feed the fish. This tank comes with a three stage hidden filtration system which also has an adjustable flow rate.

This aquarium is very stylish with its curved glass edges, and the company who created it are one of the most well known in the industry, known for their excellent customer service.

  • This tank is easy to clean and maintain.
  • The filter has an adjustable flow rate.
  • LED lights have two settings (daylight and moonlight).
  • Very secure lid.
  • The lighting is not ideal for plants which need plenty of light.
  • You can not add a heater to the back plastic section.
  • The filter is too strong for some fish (e.g. a Betta).

Check On Amazon

Beginner 3 Gallon Fish Tank

GloFish Aquarium
GloFish Aquarium

This 3 gallon aquarium would make a perfect tank for a beginner, or a first child’s tank.

Check On Amazon

This small tank is perfect for either beginners or as a child’s first tank. It will fit perfectly in a small space, such as a kid’s bedroom, or on an office desk at work.

It has unique white and blue LED lights which really bring out the colors of any fish you decide to keep.

This tank comes with a Whisper filter which keeps the water clean for your fish, and is also very quiet. It also comes with the aquarium, a cover, an internal filter and also a medium filter cartridge.

  • It comes with easy to read instructions.
  • This is perfect for beginners.
  • The lights are bright.
  • This tank is good value for money.
  • The filter has an adjustable flow.
  • You will need a heater if you keep tropical fish.
  • The lid doesn’t attach firmly to the tank.
  • This is an acrylic tank rather than glass.

Check On Amazon

Best Value 3 Gallon Aquarium

Koller Aquaview 3 Gallon Tank
Koller Aquaview 3 Gallon Tank

This easy to set up tank is cylindrical shaped and made with one piece of plastic which provides strength and durability.

Check On Amazon

This tank is perfect for a child’s first tank due to the material it’s made from, and its shape.

As a cylinder, there is no chance of bumping into a hard edge of the tank, and the materials used are also very strong and durable. It is easy to set up and comes with energy efficient LEDS and also has a timer.

This aquarium also comes with an internal filter which cleans the water at a rate of 25 gallons per hour.

  • Unique, one of a kind style.
  • Ideal for families with children.
  • It is very well priced.
  • Easy to maintain and clean.
  • Cylindrical shape makes it tricky to decorate.
  • The lights need batteries.
  • Not ideal for fish that need horizontal swimming space.

Check On Amazon

3 Gallon Fish Tank For Betta

Aqueon 3 Gallon Tank
Aqueon 3 Gallon Tank

This glass aquarium is perfect if you’re looking for a high quality, starter kit for your Betta.

Check On Amazon

The Aqueon 3 gallon fish tank is a stylish and modern looking tank which is perfect for beginners who want to try their hand at fishkeeping.

This uniquely shaped triangular tank is sure to be the center point of wherever you want to place it, from a counter-top in the kitchen, to your desk at work.

It comes complete with soft white LED lights which are concealed, and an internal filter which comes preloaded with a carbon filter.

You will need to move your Betta to a 5 gallon tank as they mature.

  • The LED lights are really bright.
  • Tank is affordable and good quality.
  • It has a small footprint, perfect for small spaces.
  • Changing the filter media is really easy.
  • The filter is not very strong, but it’s ideal for a tank this small.
  • You need to add a heater if you want to keep tropical fish.
  • There are a few areas around the top which are difficult to clean.

Check On Amazon

3 Gallon Fish Tank Equipment

3 Gallon Tank Set Up

Starting a new fish tank is not as simple as filling it with water then adding some fish, there are lots of other components.

Sometimes you will buy a tank that comes as part of a kit which contains everything you need to get it up and running. This isn’t always the case though.

Here is a list of all the equipment you will need:


A tank is not complete without a filter – not if you want it to be a healthy environment. This is one of the most important aspects of any aquarium since it’s responsible for cleaning the water.

Excess food, decaying organic matter, harmful chemicals and waste products are all removed as water passes through the filter.

This is crucial for a 3 gallon tank because it contains a low volume of water. This makes it easier for pollutants to quickly build up, so an effective filtration system is a must.

Water is drawn in at the inlet, passed through the filter media, and then released back into the tank. The filter media should be replaced every month or two so everything keeps functioning smoothly.


Not all tanks will need a heater. They should be put in setups with fish that are naturally from warm waters. This normally includes tropical and marine fish, but a marine setup isn’t an option for a tank this small.

Your tropical fish will need the water heated within a certain range. This will vary between species, so you will have to do a little research to find the ideal temperature.

Heaters come in lots of different sizes. Larger ones are used in larger tanks because they need to be more powerful to heat the extra water. A 3 gallon tank needs a small heater.

A heater for this tank will be between 10-15 watts.



Most species need a source of light to signal day and night. If you are keeping any plants then light is crucial for photosynthesis and growth.

Bulbs can be bought which produce various light intensities. It is your job to research the light you buy to make sure it is safe for all the life in your aquarium.

Other Equipment

Tanks this size don’t usually come with a stand because it can fit on most surfaces. Find a surface in your home which is bigger than the bottom of the tank and can support its weight when filled with water.

A tight-fitting hood is important too, it stops fish jumping out the top.

The bottom of the tank should be coated with an inch-thick layer of substrate. Gravel is usually okay, but some bottom-dwelling fish might prefer sand.

You can then place some decorations on top of the substrate. You don’t have much space, so you won’t be able to fit many in, ideally most of the space will be left empty for the fish to swim in.

A thermometer is useful for checking the temperature is correct. Placing it at the opposite end to the heater gives the best estimate of the overall temperature of the water.

Cleaning equipment (like algae magnets and gravel vacuums) is helpful during cleaning sessions. A fish net is the easiest way to move fish to different tanks. Any water that is poured into the aquarium must have first been treated with dechlorinator, to remove the toxic chlorine from tap water.

Best Fish For 3 Gallon Tanks

Neon Tetras

There are lots of species available in the fishkeeping world, but only a small selection can be kept in a 3 gallon tank.

Your fish need to be small enough to fit comfortably or they will become stressed and/or diseased. You won’t be able to fit many individuals in either, as each fish you add needs its own space.

Juveniles can be a good option. They are much smaller, but you will need to move them into a bigger tank as they grow to avoid overcrowding.

Here are a few options for a tank of this size:

  • Otocinclus – This small bottom-dweller will help to clean your tank by eating the algae from surfaces.
  • Guppies – They come in lots of different colors, so they can brighten up any tank.
  • Neon Tetras – These are one of the most iconic aquarium species. They shoal to produce some bright colors.
  • Zebra Danios – This is a hardy species, making it great for beginners.
  • Bettas – These will have to be kept singly. Not only are they aggressive, but they are larger than most options.

Ideally, all these species need larger tanks to grow healthily so should be moved as they mature.

You could keep invertebrates in a 3 gallon tank. In fact, they will be much more comfortable than fish because they don’t move around as much.

Dwarf shrimp like Harlequin or Cherry Shrimp can be kept in groups of 5-8. Small snails, like Ramshorn Snails can also be kept in similar numbers.

3 Gallon Fish Tank Ideas

3 Gallon Aquarium

Fish tanks can have many different functions. A 3 gallon tank is too cramped to house most fish, but a small tank like this can have other uses.

1. Nano Tank

This is a term for small aquariums – there is no strict definition but nano tanks are generally less than 10 gallons.

Only small species will fit in a nano tank, and you can’t keep many individuals. In a 3 gallon nano tank, you would be limited to just a single Betta.

2. Quarantine Tank

Disease can be a big problem in some tanks. If there is an outbreak, it can quickly spread to all your fish.

Spotting the symptoms early is key. If you suspect one of your fish is sick, move it to the 3 gallon tank. This then becomes a quarantine tank. The infected fish is isolated, so it can’t spread the disease. Once it has recovered you can move it back into the original tank.

If you are uncertain about the health of your fish when you first get them, quarantining them before adding them to your main tank is a safer option.

3. Breeding Tank

Small tanks make good breeding tanks because most of the fish will be juveniles, so they are small enough to be comfortable in just 3 gallons.

If you see that one of your fish is pregnant, you can move them into the 3 gallon tank until they give birth. The juveniles will need to be moved once they have outgrown the tank.

4. Feeder Fish

Live foods are a healthy option at feeding time. A 3 gallon tank gives you the opportunity to grow your own live foods.

Feeder fish are small species that are bred to feed to your larger fish. You can grow them in the 3 gallon tank then move them to your main tank for feeding.

5. Paludarium

Another option is to enter the plant kingdom by trying a paludarium.

Instead of mixing plants and fish, you remove the fish and fill the space with a dense collection of plants.

You still need to bear in the mind the space requirements of your plants – if they are too dense then they will compete with each other for resources.

Frequently Asked Questions

How Many Fish Can I Keep In A 3 Gallon Tank?

This will depend on the species you intend to keep. There isn’t much room, so numbers will be low. For example, you will only be able to keep Bettas on their own.

Shoaling species need more space, so you can keep them in an adequately sized group – they need plenty of swimming space too.

Should I Use A 3 Gallon Tank?

This size is too small to keep fish in over long periods. There usually isn’t enough swimming space and some species will outgrow the tank as they mature.

There are other ways you can use the tank though. 3 gallons is enough for a quarantine tank, breeding tank or to hold feeder fish.


The Tetra Aquarium
The Tetra Aquarium

Ideal for both starters and experts alike, this tank is ideal for small tropical fish.

Check On Amazon

If you are starting a new aquarium, you want the largest size you can afford/fit. A bigger tank is easier to maintain, provides more choice when filling it and gives more room to your fish.

As one of the smallest tanks available on the market, a 3 gallon tank is best used when fish are only in them for a short period.

Perhaps your fish keep getting pregnant and you need somewhere for them to safely give birth. Maybe a fish is sick and you need to isolate it, to protect the others. A 3 gallon tank can fill these roles well.

Before purchasing, you need to think about both your needs and the needs of your fish.

What do you use your 3 gallon tank for? Let us know in the comments section below…

About Robert 202 Articles
Robert Woods is the creator of FishKeeping World, a third generation fish keeper and a graduate in animal welfare and behavior. He is also a proud member of the Association of Zoos and Aquariums, the Marine Aquarium Societies of North America and the Nature Conservancy.

Be the first to comment

Leave a Reply

Your email address will not be published.