Best Fish for 5-gallon Tanks

Top 10 Best Fish for 5-gallon Tanks

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There is a surprising number of options out there if you plan to get the best fish for 5-gallon tanks. Although aquariums of this size are too small for many fish, there are still numerous that can thrive!

This list will bring you the best options and provide some useful information about each.

First and foremost, before diving into what fish species you can keep, there are many other factors that you need to consider when stocking your 5-gallon tank.

What to Consider for a 5-gallon Tank

A small tank is very attractive as the first aquarium for beginners to the hobby. Many small aquariums are appealing-designed, which will fit onto a desktop or counter, and are much more affordable than larger ones.

That said, a nano aquarium (typically defined as a freshwater tank with a capacity of fewer than 10 gallons) does significant limit your choices. That is because only a few species will grow and do well in such small tanks.

Filtration & heater

No matter what size tank you opt for, you need to install a filtration system for it. A heater will also be needed if you decide to house tropical fish. And before introducing fish or inverts to the tank, you will have to run the setup through the nitrogen cycle.

All living critters produce waste. That waste will decompose, and when it breaks down, it releases ammonia and nitrites. Those substances are extremely toxic to your aquarium pets.

A filtration system operates by circulating the water around the aquarium, passing the toxin-laden water through sponges or other kinds of filter media. The mechanical filter media eliminates large particles of waste from the water, and the bacteria held in the biological filter media process and neutralize the toxins, maintaining the water clear and clean for your fish.

Fish size & behavior

Popular tank fish species vary significantly in their size and behaviors, which needs your careful consideration when picking fish for a 5-gallon tank.

Fish grow fast!

Most of the fish species sold in fish stores are juveniles. That adorable little once-inch long fishy that looks so charming will undeniably grow, often rapidly, into an adult that could reach 8 inches.

Moreover, some fish are schooling species that might feel stressed if they are not raised in groups of at least 6 individuals. Tiny fish are especially susceptible to stress if kept alone or in couples.

In the wild, a big shoal of nano fish feels like far safer place to be than on your own or with just one mate, and it’s also true in the captive environment.

Meanwhile, a few fish can be aggressive and feel happy when kept alone, making them fitted to a solo life in a small tank than as members of a community tank.

Some fish tend to be active and require much space to swim and play. For these species, a 5-gallon tank will not be a great choice.

Therefore, do research on the fish before you introduce them to the tank and ensure that their size and behavior suit your 5-gallon tank.

Tank shape

When stocking any aquarium, the shape of the tank is a crucial consideration. Square aquariums, cube-shaped, and tall hexagonal tanks are much more challenging to stock and decorate than long, rectangular ones.

Fishbowls and vases are not suggested for keeping fish. Both types of containers have limited space and water surface area, which means that the levels of dissolved oxygen in the water are usually low. That’s harmful for any creatures living in the bowl. Plus, it’s hard to filter a bowl properly, resulting in poor water quality and a high fish mortality rate.

Top 10 Best Fish for 5-gallon Tanks

1. Guppies

Guppy Fish
Guppy Fish

Guppies are one of the most famous fish in the aquarium community. Suitable for seasoned aquarists and newbies, they are not demanding. These species can get by with very little space, thanks to their small size.

These fish for 5-gallon tanks only grow up to 2 inches at the largest. However, don’t let that fool you into thinking fish are boring or dull. Male guppies feature a fan-like tail filled with stunning colors and patterns.

Even in a small tank, the fins are striking. There are more than 300 guppy varieties. They are also peaceful and friendly fish. Keep a couple in a small tank, and you can enjoy their playful demeanor without a huge space commitment.

Learn more: Pregnant Guppies: Signs, Care, and Guppy Fry

2. Neon Tetra

Neon Tetra
Neon Tetra

No discussion about the best fish for 5-gallon tanks is complete without listing Neon Tetra. These brightly colored creatures are incredibly popular. They are a schooling species that grow well in a community. Provided that they have others around them, they feel happy.

Neon Tetras sport a torpedo-shaped body with a long stripe of iridescent shimmering blue running along the body. There’s also a splash of red accenting the tail.

Easy-going and well-behaved, these kinds of tetras are a relatively low-maintenance species. Besides, they are hardy and tolerant of a range of environments. However, they would love conditions that replicate their natural habitat.

3. Sparkling Gourami

Sparkling Gourami
Sparkling Gourami

Sparkling Gouramis are fairly easy to please when it comes to room requirements because they only grow up to a mere 0.5 inch in size. The small stature of the fish lends credence to its common name. A widely-seen shoaling species, big swathes of fish produce a glimmering display that catches your eyes.

These fish have many colors packed into their small body. If looking closely, you will find polka-dotted fins, stripes or red and a bright blue eye.

Sparkling gouramis are active, playing around the confined space to get their exercise fish.

4. Molly Fish

Molly Fish
Molly Fish

Molly fish, or mollies, are a typical community staple. Intelligent and self-sufficient, mollies are easy to take care of. They are undemanding and can breed prolifically with your minimum intervention.

The best part of raising a molly is that it’s highly adaptable. While they have their own preferences, the parameter range is fairly wide with the fish. They can grow in everything from barren freshwater tanks to lush brackish waters.

Mollies are available in a lot of colors. Moreover, they can also take on a few different fin shapes, offering you numerous aesthetic options.

5. Honey Gourami

Honey Gourami
Honey Gourami

Similar to standard gouramis, Honey Gouramis feature slim bodies leading to a point at the supra terminal mouth. They even sport thread-like fins that are iconic for the gourami fish.

That said, these fish have a fairly different color. They have an orange-red color, which is a shape difference from the blue hues of standard gouramis.

Honey Gouramis are small, growing up to 2 inches as adults. That makes them ideal fish for 5-gallon tanks.

The fish are peaceful and might be timid around active fish. Therefore, they do well in closer quarters around others. These creatures need clear access to the water surface because they are air-breathing labyrinth species.

6. Dwarf Pea Puffer

Dwarf Pea Puffer
Dwarf Pea Puffer

These cure little creatures have become common in the past few years.

The fish have a dense and stout body with a bright yellow belly. Their head features swirls of green, black, brown, and shimmering gold. Tiny fins and large, bulbous eyes make the fish look like a cartoon character.

Dwarf Pea Puffers only reach about 1.5 inches when fully grown. That’s why they are perfect fish for 5-gallon tanks.

You won’t see your fish darting through a tank. Even though they are active and love moving, they are not the most powerful swimmers. You might see them swimming through vegetation when they hide.

7. Least Killifish

Least Killifish
Least Killifish

At only about 1 inch long, Least Killifish do well in cramped quarters. They can thrive in rougher conditions that other fish can’t stomach.

Least Killifish hail from stagnant bodies of water and sluggish waterways. You can see them in coastal lowlands, searching through fairly barren environments to seek food.

These creatures can well adapt to a rough life, making it a walk in the park in tanks. They are easy to feed and can grow in small spaces without missing a beat.

Sometimes shy and standoffish, the fish don’t like plenty of racket. They love staying in their own lane and mind their business.

8. Harlequin Rasbora

Harlequin Rasbora
Harlequin Rasbora

While not the brightest-colored species in the aquarium world, Harlequin Rasboras still can attract your eyes. Their diamond-shaped body is blended with a triangular patch of black. It covers the lower half, generating a sharp contrast.

Being hardy community fish, these creatures live well in tropical conditions and can get along with almost any mates. In addition, Harlequin Rasboras prefer blackwater environments, enjoying the perks that come with tannin-filled water.

9. Clown Killifish

Clown Killifish
Clown Killifish

Originating from small streams in West Africa, Clown Killifish don’t expand up to 1.5 inches long.

Despite their tiny stature, these fish are natural-born micro predators. They stick to the water surface to look for insects and tiny microorganisms to consume.

Look at Clown Killifish closely, and you’ll find they are adorned with different colors. Their dart-shaped body contains stripes of black, subtle yellow accents, and several splashes of bright blue.

10. Celestial Pearl Danio

Celestial Pearl Danio
Celestial Pearl Danio

Celestial Pearl Danios are a greatly sought-after fish with their eye-catching appearance. Their body is mostly covered in deep blue, along with cream-colored patches, replicating the look of a starry night.

Their fins are bright red, which are covered with distinct black stripes. The appealing combination of colors and patterns makes the fish one of the most stunning around.

It’s relatively straightforward to care for these creatures. They are native to clean bodies of waters covered with dense vegetation. Hence, they require proper conditions, many hiding places, and a balanced diet to stay healthy and happy in captivity.

Final Words

The best fish for 5-gallon tanks can still provide a good deal of enjoyment and fulfilment for aquarists. These tiny pets are brilliant, fun to watch and rewarding to handle.

If you know a good fish species in mind that didn’t appear in the list, feel free to share it with us and other readers.

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