Top 10 Stunning Nano Fish for your Next Small Fish Tank


Top 10 Stunning Nano Fish for Your Next Small Fish Tank

Nano fish tanks are very popular for their beauty and compact size, but it can be challenging to find animals that are tiny enough to comfortably live in them. If you only have room for a 5- to 20-gallon aquarium, check out our top 10 small aquarium fish that are known for their vibrant colors, fun personalities, and unique appearances.

1. Celestial Pearl Danio

Danio margaritatus

This little fish is also known as the CPD or galaxy rasbora. It has been very popular since its discovery in 2006. It is a miniature trout that was originally from Southeast Asia. It has shiny golden spots and bright orange tails. These schooling fish can be quite expensive at $6-10 per piece, so make sure you save enough money to buy at least six. CPDs are known to be a bit shy, so make them feel safer by increasing the size of their group and providing plenty of decorations and aquarium plants as cover. CPDs prefer to be fed in the middle of the water, not at the bottom or top, so make sure you choose small, slow-sink foods like frozen cyclops, baby brine shrimps, and daphnia.

2. Chili Rasbora

Boraras brigittae

Chili rasboras get their common name from the fiery red color they display as full-grown adults, but most of time you see juveniles at the fish store that are much paler in appearance. Your patience will pay off when they turn a vibrant color six months later if you bring them home. This fish is the smallest on our list and can grow up to 0.8 inches (2cm) in length. They have a very thin profile. Because of their petite size, they look better if you get at least 10 brigittae rasboras in a school and put them against a lush green background of plants. As with the celestial pearl danios, feed them tiny foods that swirl midwater in the aquarium, such as baby brine shrimp, crushed flakes, and Easy Fry and Small Fish Food.

3. Pygmy Corydoras

Corydoras pygmaeus

Because they are only 1 in (22.5 cm) tall, pygmy corydoras can be as cute as baby cory cats. They pair well with the previous schooling midwater fish because they can use their whisker-like barbels to detect and clean up any crumbs that fall past them to the ground. They will eat almost any type of fish food, including Repashy gel foods and sinking wafers. Pygmy corys, a schooling fish, require at least six fish to feel comfortable. However, if they are difficult to find in fish shops, you might consider other dwarf corydoras species like C. habrosus or C. hastatus. For more info on how to care for cory catfish, see our care guide.

4. Kuhli Loach

Pangio kuhlii

Although this bottom dweller can grow up to 4 in (10 cm) in size, it is not a micro fish. However, their slim, eel-like bodies mean that they don’t produce much bioload. Their unusual appearance and peaceful demeanor make them the perfect oddball creature to keep with your other nano fish. Because they don’t have a preference for food or water parameters, kuhli loaches make a great starter fish. Additional color options are available in the black kuhli locach (P. ablonga) or silver kuhli loiach (P. andaris). The full care guide can be found here.

5. Green Neon Tetra

Paracheirodon simulans

Paracheirodon Simulans, a slightly smaller cousin to regular neon tetras, is only 1-1.25inches (2.5-3cm) long. It doesn’t have a lot of red stripes and it isn’t as large. Its body is covered in a bright, blue-green horizontal stripe, which shines brilliantly even at night. Although they can survive in more acidic water, they will thrive in tropical community tanks that have the same water parameters. You should have at least six to eight green neon tetras in your tank. Give them small, slow-sinking fish foods. Also, many of them are caught from the wild and may come with fin rot or ich, so make sure to quarantine them after purchase to prevent disease from spreading to your other aquariums.

6. Clown Killifish

Epiplatys annulatus (male is above and female is below)

The rocket killifish or banded panax is famous for its dark vertical stripes and brilliant tail. This tail looks like a flame coming out of an explosion. Males are able to display all the colors while the females have a banded body and a clear tail. The guys can get territorial so aim to have one male for every 2-3 females. This 1.5-inch (3.8 cm), top-dwelling fish prefers to hang out in the upper third of the aquarium, so use a tight-fitting lid with all the holes plugged up so that they won’t jump out. They will start to spawn and scatter their eggs if you give them floating food like frozen tubifex worms or flakes. For more details, read our article on clown killies.

7. Ember Tetra

Hyphessobrycon amandae

This 0.8-inch (2 cm) tetra from Brazil boasts a bright orange-red body that lights up any aquarium, especially those with lush, green plants. They can be kept in both a small tank or as a group of 20-30 fish in larger tanks. Unlike many nano fish, ember tetras are relatively outgoing and eagerly eat from all levels of the aquarium. You can feed them floating or sinking food like Hikari Micro Pellets and frozen daphnia.

8. Panda Guppy

Poecilia reticulata

Finally, we have a livebearer (or fish that bears live young) on our list. Guppies are a well-known breed, and can grow to as much as 2.5 inches (6 cm) in length. Panda guppies are specifically bred to maintain a small size with a shorter tail, such that males come in around 1 inch (2.5 cm) and females around 1.75-2 inches (4-5 cm). They are a striking combination of black, silver, and blue colors.

Compared to other fancy guppies, we don’t find them to be very fussy and have even raised them in an outdoor mini pond during the warmer summer season. If you have soft water, Wonder Shells and Seachem Equilibrium might be a good choice. They prefer a higher pH and GH with greater minerals. Fortunately, they are easy to feed and readily eat at all levels of the aquarium, so you don’t need to get a bottom dweller to clean up your nano tank. Panda guppies is one of our favourite varieties so we recommend giving them a try. For more information, see our complete guppy care guide.

9. Spotted Blue Eye Rainbowfish

Pseudomugil gertrudae

Pseudomugil rainbowfish, Gertrude’s rainbowfish, is a great option if you love rainbowfish but don’t have enough space. This 1.5-inch (3.5cm) species is beautiful with bright blue eyes, black spots, and a yellow body. Although the males are brighter than the females (depending on their native region), you can get one male to every two females. This will ensure that the boys show off the best colors and perform unique sparring moves. They prefer higher pH and GH but can survive in a wide range of temperatures, just like the guppies.

As a surface-dwelling fish that likes to swim in the top half of the aquarium, get a tight-fitting lid to prevent jumping and feed lots of floating foods like flakes and freeze-dried foods. Although Pseudomugil Rainbowfish are vibrant and beautiful, their lifespan is shorter. Therefore, you might consider breeding them with dense floating plants such as guppy grass or yarn spawning mop.

10. Borneo Sucker Loach

Gastromyzon sp.

We also have an algae eater to help you keep your nano fish tank healthy. Gastromyzon genus is made up of small hillstream loaches, which are typically 2 inches (5cm) long. These loaches look like miniature stingrays and flounders. They are similar to their larger cousin the reticulated hillsstream loach. They enjoy eating algae, cleaning up driftwood and scavenging leftovers. They can be kept in normal community tank parameters, but also have the ability to tolerate the cooler temperatures of an unheated aquarium. Borneo sucker loaches can show some territorial behavior toward their own kind, so either get one individual or a group of three or more.

If you are unable to find these fish at your local fish store, check out our favorite online retailers to see about ordering them online. We wish you all the best with your nano tank. Enjoy nature every day.