People who love keeping fishes don’t necessarily have to invest in a large fish tank. A 5-gallon aquarium can allow them to fulfill their hobby. These tanks take little space and are easier to maintain than larger tanks. There are quite a few freshwater and saltwater fishes that will do well in a 5-gallon tank. Here are the best fish for a five-gallon tank that you can consider.
Betta

Betta is the most popular choice when it comes to the best fish for a five-gallon tank. These freshwater fishes are beautiful creatures that look mesmerizing in aquariums. The males of the species are more popular among hobbyists as compared to the females. Tanks with standard gravel and tropical conditions will be ideal for keeping Betta fishes. You can keep a single Betta fish in a five-gallon tank. You will need a larger aquarium for keeping a pair of Betta fishes as they need adequate space and can be aggressive towards other Betta fishes.
Least Killifish

Least Killifish is a low-maintenance species among the best fish for a five-gallon tank. It is one of the smallest freshwater fishes. The fish thrives in temperatures between 65 and 75°F and in waters with normal pH levels. It is quite resilient and will be suitable for beginners. Least Killifish are peaceful by nature and prefer to live in schools. You can keep three Least Killifish in a five-gallon tank easily. They prefer to be around plants and in aquariums with low water flow. Least Killifish are not suitable for keeping with other species of fish as they might be perceived as food.
Chili Rasbora

Chili Rasbora is a great choice if you want multiple fishes in your aquarium. It grows to a maximum length of 18-20mm and is reddish in appearance. It is the best fish for a five-gallon tank if you want four or five fishes in it. These fishes like soft water with a pH of less than 5.0, although they can live in water having up to 7.0 pH levels. They prefer a general hardness between 1-2° and temperature from 72 to 82°F. Aquariums with fine gravel, subdued lighting, and slow-moving water will suit them.
Bumble Gobies

Bumble Gobies is another species for the hobbyists who want the best fish for a five-gallon tank. They are more suitable for saltwater tanks even though they can survive in freshwater. These fishes grow up to 1-1/2inch at max, and you can place a few of these in a 5-gallon aquarium. Bumble Gobies can be aggressive towards other fish species and should ideally be placed with their own species. They do well in tanks with a pH of 6.5-8.5 and temperatures from 71 to 84°F. The water must be regularly filtered while maintaining proper salinity levels for keeping Bumble Gobies.
Dwarf Puffer

Dwarf Puffer is a small-sized fish species for the people who want the best fish for a five-gallon tank. It is an energetic fish that grows up to 1-inch in length. These fishes tend to be aggressive and don’t do well with other fish species. You can place one or two dwarf puffers in a single five-gallon tank. Aquariums with a sand substrate are more suitable for them though they do fine in gravel also. They prefer a temperature of around 75-82°F with 7.0 water pH level. Adequate plants and decorations that provide hiding spots should be available to the Dwarf Puffer in the aquarium.