Last Updated on February 11, 2023 by Jakob

A 5 gallon fish tank is a brilliant way of starting out on your aquarium journey. With many fish tank kits available that include a filtration system and LED lighting they can be very easy to set up. They are also a perfect size to practice aquascaping on! There are many different ways to stock a tank of this size, and in this article we will go through the best fish for 5 gallon tank aquariums.

Not only will we go through what fish you can stock in a 5 gallon tank, we will also go through what fish you shouldn’t house in a tank of this size. Aquarium plants are very important in a fish tank, providing natural filtration as well as making the tank more natural for your fish. As such we will go through possible plants as well. 

There are many ways to stock a 5 gallon tank, but there are many more ways to not stock a 5 gallon fish tank. Ensure to read the section on the fish not suitable for a 5 gallon tank. Many fish that are touted as suitable, such as white cloud mountain minnows and neon tetras, in fact won’t do well in a nano tank.


Best Fish For 5 Gallon Tank Aquariums

To get started we’ll jump straight into the fish that you will be able to successfully house in a 5 gallon fish tank. 

Betta Fish (Betta splendens)

Betta Fish for 5 gallon tank

  • Temperament: Semi-aggressive
  • Care Level: Intermediate
  • Size: 2 – 4 inches
  • Tank Setup: Tropical freshwater

Betta fish are perhaps the most elegant fish for a 5 gallon fish tank. 5 gallons is however the absolute minimum sized tank that Bettas can be housed in. Betta fish in bowls absolutely does not work, as the water chemistry will soon go downhill. A 10 gallon fish tank would be a much more comfortable fit for a Betta fish.

Bettas have long flowing fins and are available in radiant colors. They are also known to recognize their owners! All in all you will not regret having a Betta fish in your 5 gallon aquarium.

Least Killifish (Heterandria formosa)

Least Killifish 5 gallon

Credit: Brian Gratwicke (Flickr)

  • Temperament: Peaceful
  • Care Level: Easy
  • Size: 0.5 – 1.2 inches
  • Tank Setup: Tropical freshwater

Least Killifish are great fish to watch. They are tiny fish, and have the title of smallest livebearer! Very peaceful, they are perfect for community tanks as well as on their own in a small 5 gallon fish tank. A 5 gallon aquarium has space enough for 2 or 3 Least Killifish. This should be a group composed of only one male, and one or two females. 

Least Killifish are brilliant fish. While not the most colorful; they have quite muted colors such as tan, cream, beige, and brown, they have a strong black line which is easy to spot darting around the tank.

Very hardy, they are able to thrive in a range of conditions and are able to survive fluctuations that may harm other fish species. These fish will most likely breed, so have a plan of action for what to do with the ensuing fry. 

Clown Killifish (Epiplatys annulatus)

Clown Killifish 5 gallon tank

Credit: Carnat Joel (Flickr)

  • Temperament: Peaceful
  • Care Level: Easy
  • Size: 1.2 – 1.4 inches
  • Tank Setup: Tropical freshwater

Clown Killifish are stunning creatures; they have a black and white striped body with an amazingly colorful tail of reds, yellows, and blues, similar to clown makeup which is where their name is derived. Being sexually dimorphic it is easy to distinguish between males and females. Males have more colorful fins than the females.

Having these amazing fish in a small 5 gallon tank is a real treat. They are ambush surface predators, and so their behavior emulates this. The flash of color of their fins is absolutely fantastic.

In a 5 gallon tank you should stock two Clown Killifish; one male and one female. There could be a case for two females and one male, but be very careful with the water chemistry. 

Pea Puffer (Carinotetraodon travancoricus)

Fish for 5 Gallon Tank

  • Temperament: Aggressive
  • Care Level: Intermediate
  • Size: 1.4 inches
  • Tank Setup: Tropical freshwater

The Pea Puffer, or Dwarf Pea Puffer, is an extremely small freshwater pufferfish. Pufferfish are members of the family Tetraodontidae, which are primarily marine species. Therefore having a freshwater member of this family is a real talking point!

A 5 gallon tank can house a single Dwarf Pea Puffer. If you want to have more individuals they will need the appropriate amount of space. 

Pea Puffers need a varied diet to remain healthy, which includes both live and frozen brine shrimp and bloodworms, and copepods and rotifers. They will also eat small snails such as malaysian trumpet snails. Pea Puffers are often associated with Cabomba plants, and the presence of these plants reduces mortality in captive Dwarf Pea Puffers.

With its yellow coloration and dark spotted body, the Pea Puffer is guaranteed to be a hit in your tank. They also have amazing independently rotating eyes!

Best Invertebrates For 5 Gallon Tanks

While it is easy to get caught up in the available fish for 5 gallon tank aquariums, a thought must be spared for invertebrates. Invertebrates can be fantastic additions to 5 gallon tanks, especially if you have a well planted setup. Being in a smaller tank it is much easier to spot invertebrates as they can easily hide in larger tanks. 

Cherry Shrimp

Cherry shrimp fish for 5 gallon tank

  • Temperament: Peaceful
  • Care Level: Easy
  • Size: 1.5 inches
  • Tank Setup: Tropical freshwater

Cherry Shrimp can add a real burst of color to your 5 gallon fish tank. While you may scoff at having only shrimp and no fish in your tank, these shrimp can really add a burst of color and character to any tank. In a 5 gallon tank, you will be able to keep between 10-25 Cherry Shrimp depending on how good the filter is. Always err on the side of caution, you can always add more shrimp later!

Although you may not think it, Cherry Shrimp are susceptible to changes in water chemistry, so ensure that you regularly test the water to ensure that correct levels are maintained.

Cherry Shrimp love a planted tank and having decorations to explore and hide in. A fine substrate will allow them to comb through and find algae and bacteria mats to feed on. Feeding them specialist shrimp pellets will help them to get all the food that they need; don’t rely on the presence of algae!

Hikari Tropical Shrimp Cuisine Fish Food, 0.35 oz (10g)
  • Formulated diet for all types of freshwater ornamental shrimp
  • Natural color enhancers like spirulina, seaweed and alfalfa meal
  • Includes astaxanthin which helps to reduce color fading
  • Vitamin and mineral mix that supports immune system health
  • Promotes proper ecdysis (moulting)

Nerite Snails

Nerite Snail

Credit: James St. John (Flickr)

  • Temperament: Peaceful
  • Care Level: Easy
  • Size: 1 inch
  • Tank Setup: Tropical freshwater or saltwater

Nerite Snails are extremely easy to care for and are prolific algae eaters, helping to keep your aquarium clean and tidy. However they do have a preference for algae, rather than man-made foods, so you may have to encourage algal growth slightly. It is recommended to only have one snail in a 5 gallon tank, but they can be kept with other invertebrates such as cherry shrimp for a unique tank setup.

These snails are very striking in appearance. They are often covered in black stripes, and are very easy to spot. Nerite snails prefer a well planted tank with a good substrate. 

Nerite snails can be housed in both freshwater and saltwater tank setups. Most commonly found in marine environments, they are happy in freshwater as well. Although juveniles need to find saltwater soon after hatching in order to survive. This can be a blessing in freshwater tanks, as you won’t be overrun with snails!

Dwarf Crayfish (Cambarellus sp.)

Dwarf Crayfish stocking 5 gallon tank

Credit: Veitw, CC BY-SA 3.0, (WikiCommons)

  • Temperament: Peaceful
  • Care Level: Easy
  • Size: 2 inches
  • Tank Setup: Tropical freshwater

While dwarf crayfish can be kept in a 5 gallon aquarium it is generally recommended to keep them in a larger tank. It is easy to see why these crustaceans are so popular; they are amazing additions to the base of any aquarium. 

Dwarf crayfish need plenty of hiding spots in the tank. This is so that they can retreat and hide after moulting. Their exoskeleton is soft directly after moulting and they are very vulnerable. Having lots of hiding places is essential for them until their exoskeleton hardens.

There are many species of dwarf crayfish, all in the Cambarellus genus. By far the most popular is Cambarellus patzcuarensis, which has been bred in the aquarium trade to be a bright orange color. This makes it very striking and a wonderful addition to a 5 gallon tank!

Best Plants For 5 Gallon Tanks

In our view, having live plants in a fish tank is as important as the substrate, or having a functional filter or aquarium heater. Not only do they make the aquarium look much more natural but they make the fish and invertebrates feel more at home and comfortable, as well as offering natural filtration.

Most of the plants on this list are column feeders, drawing nutrients from the water. Using an aquarium fertilizer will enable these plants to thrive!

Java Fern

Java Fern Microsorum pteropus

Java Fern is an incredibly popular freshwater aquarium plant, known and loved for its stunning looks and ease of care. It is a very hardy plant, which makes it perfect for 5 gallon tanks. It is able to thrive even in low light conditions, which is amazing as many 5 gallon fish tank kits come equipped with LED lighting not powerful enough to sustain high light plants.

There are a few different varieties of java fern, so you can be sure to find one that suits your tank exactly. Be sure to place them in the tank properly; they don’t have proper roots. Instead they have rhizomes which can’t be buried in substrate. Rhizomes instead need to be attached to rock, driftwood, or other decorations. 

Java Moss

Java Moss

Credit: AJC1 (Flickr)

Java moss is a plant favored amongst both beginner and experienced aquarists. It is a fantastic looking plant which is brilliant for aquascaping a tank as well as providing a brilliant habitat for fish and shrimp. Juvenile fish often find refuge in java moss, and they are perfect for making a tank look very natural whilst keeping space in the body of the tank for fish to roam. 

Java moss is extremely hardy and can grow in a huge range of conditions. This makes it a perfect plant for beginners as it barely needs any maintenance at all, and can be utilized anywhere in the tank; in the foreground, middle, background, carpeting, or floating. Simply attach the moss to driftwood or other attachment point and the rhizomes will grow and take hold. It can be placed on substrate, or to a cork to be floated. 


HornwortHornwort is an incredibly easy plant to grow and keep in a freshwater aquarium. In fact, it grows almost too well; if you don’t work to trim it it can easily grow too big for the tank! Hornwort grows from a central base and produces many branches, creating the effect of multiple plants from only one individual. 

Hornwort provides great shelter for fish and shrimp alike, which find it easy to become lost in the leaves. It is found throughout the world and can thrive in virtually any freshwater environment. As such it is almost impossible to kill, making it a perfect plant for beginners. It is perfectly happy both floating or rooted in the substrate.

Marimo Moss

marimo moss ball

Marimo moss balls can create a great centerpiece for a 5 gallon tank. When put on the substrate at the foreground of an aquarium they can lure shrimp out from their hiding places. Shrimp absolutely love marimo moss balls, often being found rooting for food amongst the moss. 

They can be a great way of utilizing excess space at the base of a tank without having to add other form of decoration. 

Anubias Nana

Anubias nana

Anubias nana is a small form of anubias which is perfect for small 5 gallon fish tanks. It is quite a short plant which makes it ideal for mid- to foreground plantin, and has nice broad leaves which look even larger in a small tank.

Anubias nana is also quite slow growing, which is ideal for small tanks. Unlike a plant like hornwort this plant isn’t going to overrun your tank if you look the other way! It can either be attached to driftwood or other decorations, or it can be planted into finer substrates where it will thrive.


Cabomba is a brilliant plant for 5 gallon tanks. Pea puffers have a higher rate of survival in tanks which contain cabomba, which shows just how valuable they can be. Cabomba can be planted into the substrate or floated on the surface. 

It is an absolutely stunning plant. It is also known as Brazilian fanwort due to the fan-like look of its leaves. The leaves grow in rings around the central stems, and are very delicate. 

Whilst not hard, Cabomba isn’t the easiest to care for. It requires a reasonable level of lighting, higher than that which is normally provided in basic LEDs. However a higher grade of lighting will provide the light it needs. There are different color varieties available, with green being more common than red or purple.

Fish Not Suitable For a 5 Gallon Tank

In order to understand how best to stock a 5 gallon tank, it is important to understand what fish aren’t suitable.

Most shoaling fish are out of the picture. Even small fish such as white cloud mountain minnows and mollies need to be in a reasonable school to be comfortable. Given the very small space that a 5 gallon fish tank allots for fish stocking, having enough individuals would crowd the tank. While having 3 or 4 white clouds would technically fit into a 5 gallon tank, they wouldn’t be comfortable with that few individuals. 

While many guides claim that fish such as guppies and endler’s livebearers can reside in a 5 gallon tank, they actually need a minimum of 10 gallons. This is due to their shoaling nature and the fact they need to be kept in a mixed sex group. In a 5 gallon tank the females don’t have enough space to retreat from the males, and they are also prolific breeders and can quickly overrun a small tank.

As you would expect, large fish are out of the picture completely. This includes fish such as plecostomus, angelfish, and other cichlids. 

Rosy loaches are a very small nano fish that are quite popular. Some guides advise that these are suitable fish for a 5 gallon tank, but this is not the case. While they are very small, being only 1 inch in length, they need to be kept in a school of at least 8. They have a social hierarchy, and constantly battle to be top fish. If they are kept in shoals of less than 8 they can become very aggressive or withdrawn. They are also very active fish and need lots of room to swim.


Hopefully this article on how to stock a 5 gallon tank has been useful! It can be easy to try and force fish such as guppies, white cloud mountain minnows, and molly fish into a 5 gallon aquarium, but these fish are shoaling fish that need to be kept in groups and need more space than is provided in 5 gallons. Individual fish can fit, but as a group they can’t. 

Bettas, least killifish, clown killifish, and pea puffers are all amazing freshwater fish for 5 gallon tank aquariums. They offer real impact and will provide a brilliant centerpiece for any aquarium. 

Don’t forget about the advantages brought to the table by invertebrates either. Cherry shrimp bring a brilliant flash of red and are great fun to watch. A planted 5 gallon tank is much more natural and offers a lot more than a plain tank.

Let us know in the comments how you stock your 5 gallon fish tank

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