Best Fish for a 5-Gallon Tank (Top 7 Picks)

A 5-gallon fish tank is a great way to start your fish-keeping journey. They’re small enough to be manageable but large enough to house a few different fish species. When stocking a small-size tank, it’s important to choose the right fish. Some fish grow too large for a five-gallon tank, and others are aggressive and may bully the other fish.

In this post, I’ll discuss the top seven options that are perfectly suited for a 5-gallon tank. I’ll consider the fish’s adult size, temperament, and dietary needs. By the end of this article, you will have an idea of the fish species that would be a great fit for your small aquarium kit.

Here is a list of the seven best fish for a 5-gallon tank:

#1. Clown Killifish

  • Size: 1.4 inches
  • Difficulty: Beginner
  • Number of Fish in a 5-Gallon Tank: 2 to 3

The Clown Killifish is a small, dart-shaped fish that is native to West Africa. They are found in shallow water habitats, such as ponds and marshes. These brightly colored fish are popular among aquarium enthusiasts for their vibrant colors and interesting patterns.

Clown Killifish are easy to care for. They’re relatively peaceful and do well with other small fish. They are omnivorous, so their diet consists of both plants and animals.

To care for clown killifish, provide them with plenty of hiding places. These fish do not like bright lights, so make sure to keep the lighting subdued.

#2. Betta Fish

  • Size: 3 inches
  • Difficulty: Beginner
  • Number of Fish in a 5-Gallon Tank: 1

If you’re looking for an eye-popping, fancy fish for your 5-gallon tank, bettas are a great option. These colorful fish originate from Southeast Asia, where they are known for being aggressive. So in a 5-gallon tank, it’s ideal to keep one betta fish.

Bettas are carnivorous fish, and their diet should consist mostly of meaty foods like pellets or freeze-dried bloodworms. They also enjoy the occasional live food treat, such as brine shrimp or daphnia.

Betta fish come in a variety of colors, so you can choose one that matches your personality. They are also relatively easy to care for. Just make sure to feed them a high-quality diet and keep their tank clean. With proper care, your betta will thrive in your 5-gallon tank.

#3. Chili Rasbora

  • Size: 1 inch
  • Difficulty: Beginner
  • Number of Fish in a 5-Gallon Tank: 4 to 5

Chili Rasbora is a small, blackwater nano fish that is known for its vibrant, popping red color and black accents. These beautiful little fish are perfect for a 5-gallon tank and make a great addition to any nano aquarium.

Chili Rasboras are peaceful fish that do well in groups of 5 or more. They are omnivores and their diet consists of small live foods, frozen foods, and flakes. These fish are easy to care for and do their best in an aquarium with plenty of hiding places.

#4. Guppy Fish

  • Size: 2.4 inches max
  • Difficulty: Beginner
  • Number of Fish in a 5-Gallon Tank: 1 to 2

When it comes to stocking a 5-gallon aquarium with fish, one of the best options is the guppy. These little fish are not only beautiful and come in a wide variety of colors, but they are also peaceful and easy to care for.

As for the number of guppies to put in a 5-gallon tank, a good rule of thumb is no more than two. This is because guppies are relatively active fish and need a bit of space to swim around.

As far as diet goes, guppies are not particularly picky eaters and will do well on most commercial fish food pellets or flakes.

#5. Sparkling Gourami

  • Size: 1.5 inches
  • Difficulty: Beginner-intermediate
  • Number of Fish in a 5-Gallon Tank: 2 to 3

If you’re looking to add a little shimmer and shine to your 5-gallon tank, then the sparkling gourami (Trichopsis pumila) is the fish for you. These diminutive freshwater fish are covered in iridescent scales that glimmer and change color in the light. In addition to their beauty, sparkling gouramis are also relatively easy to care for.

Sparkling gouramis are native to Southeast Asia, where they inhabit slow-moving rivers and streams. In the wild, these fish typically grow to be about 2 inches long. However, in captivity, they usually max out at around 1.5 inches. Given their small size, it’s no surprise that these fish do well in smaller tanks.

They are very active and love to swim around in live vegetation. Their diet consists of small insects and larvae. They are very easy to care for and make a great addition to any aquarium.

#6. Molly Fish

  • Size: 4 to 4.5 inches
  • Difficulty: Intermediate
  • Number of Fish in a 5-Gallon Tank: 1

Molly fish are a type of freshwater fish that are self-sufficient and adaptable. They are a popular choice for aquariums because they are easy to care for and have plenty of aesthetic appeals.

Molly fish size is around 4 to 4.5 inches, so it is recommended to keep one fish in a 5-gallon tank. They come in a variety of colors, including black, silver, gold, and striped. Molly fish are omnivorous, so their diet should consist of both plant and animal matter.

To keep your Molly fish healthy and happy, be sure to provide them with clean water. Regular water changes and vacuuming of the gravel will help to keep the tank clean and the water quality high.

#7. Honey Gourami

  • Size: 2 inches
  • Difficulty: Intermediate
  • Number of Fish in a 5-Gallon Tank: 2

The honey gourami is a small, labyrinth fish that is native to South Asia. It is an orange-red color with black stripes and has two pectoral fins. The honey gourami grows to be about 2 inches long and has a supra terminal mouth. They are peaceful and active fish that do well in a 5-gallon tank. 

The diet of the honey gourami consists of small insects, worms, and crustaceans. In the wild, they also eat plant matter and algae. In captivity, they should be fed quality flake food or pellet food as well as frozen or live foods. The care of the honey gourami is not difficult but they do require some specific water conditions. The water should be soft to medium hard and slightly acidic with a pH of 6.5-7.5.