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 attractive due to their small size. However, it can prove difficult to find tiny animals that will 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. Originally from Southeast Asia, it kind of looks like a 1-inch (2.5 cm) miniature trout covered in shiny golden spots and bright orange fins. They can be a little pricier at $6-10 each, so save up your money to get at least six of these schooling fish. 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. Plus, they prefer feeding midwater (not at the top or bottom of the tank), so look for small, slowly sinking foods such as frozen cyclops, baby brine shrimp, and daphnia.

2. Chili Rasbora

Boraras brigittae

Although chili rasboras are known for their fiery red color as fully grown adults, most juveniles you see at the fish market are much paler. Your patience will pay off when they turn a vibrant color six months later if you bring them home. They are the smallest of our fish and can grow to approximately 0.8 inches (2 cm) in size. Their profile is very slim. Their small size makes them look great if there are at most 10 brigittae rose rasboras placed in a school. 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

The 1-inch (2.5 cm) pygmy corydoras are incredibly adorable because they always stay the size of baby cory catfish. Because they have whisker-like barbels, they can detect and pick up any crumbs on the ground. They will eat almost any type of fish food, including Repashy gel foods and sinking wafers. Pygmy Corys are schooling fish and require six or more fish to feel at ease. If you have trouble finding them in fish stores, try the dwarf corydoras species C. habrosus, C. hastatus. Our care guide provides more information on caring for cory catfish.

4. Kuhli Loach

Pangio kuhlii

This bottom dweller is not quite a micro fish since it can reach up to 4 inches (10 cm) in length, but they do not produce much bioload or waste because of their skinny, eel-like bodies. They are a great oddball fish to keep with other nano fish due to their peaceful disposition and unusual appearance. Because they don’t have a preference for food or water parameters, kuhli loaches make a great starter fish. You can also check out the silver kuhli loaf (P. anguillaris) for additional color options. All details can be found in the care guide.

5. Green Neon Tetra

Paracheirodon simulans

As a slightly smaller cousin of the regular neon tetra, Paracheirodon simulans only gets 1-1.25 inches (2.5-3 cm) long and doesn’t have much of a red stripe. Instead, its body is predominantly covered in a bright blue-green, horizontal stripe that shines brilliantly even when the light is dim. They can live in slightly more acidic water, but otherwise thrive in standard water parameters for a tropical community tank. A school of 6-8 neon tetras is recommended. They should be fed 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 banded panchax or rocket killifish is known for its dark vertical bands and dazzling tail that looks the flame coming out of a rocket. All the incredible colors are found in the males, while the females are covered with a transparent tail and have a banded physique. 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. You can give them floating foods like freeze-dried tubifexworms and flakes and they will begin spawning and scattering eggs. Learn more about clowns and their killings in our article.

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. These tetras are extremely hardy and can be housed in a tiny tank or in a large tank with 20-30 fish. Unlike many nano fish, ember tetras are relatively outgoing and eagerly eat from all levels of the aquarium. Feast them with floating or slowly sinking foods such as Hikari Micro Pellets, Xtreme Nano Pellets, and frozen Daphnia.

8. Panda Guppy

Poecilia reticulata

We also have a livebearer, or fish that bears young, on our list. Guppies are very well-known in the hobby, but they usually grow up to 2.5 inches (6 cm) long. Panda guppies have a smaller size and a shorter tail. Males are approximately 1 inch (2.5cm) in length, while females are about 1.75-2cm (4-5cm). They have striking blue, silver, and black colors and, like most livebearers, breed quite readily.

We don’t think they are fussy, unlike other fancy guppies. In fact, we have raised them in an outside mini pond during the warm summer season. They do prefer higher pH and GH with more minerals, so consider adding Wonder Shells or Seachem Equilibrium if you have soft water. 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. You can find more information in our complete guide to guppy caring.

9. Spotted Blue Eye Rainbowfish

Pseudomugil gertrudae

If you have always loved rainbowfish but don’t have a tank big enough for them, try Pseudomugil rainbowfish like Gertrude’s rainbowfish. This 1.5-inch (3.5cm) species is beautiful with bright blue eyes, black spots, and a yellow body. The males are more colorful than their female counterparts. Therefore, you should get one male for every two women. This will allow the boys to show off their best colors as well as their unique sparring dance. 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.

The last but not the least, we offer an algae eater for your nano tank. Gastromyzon is a genus of hillstream loaches. They are usually 2 inches (5 cm) long and shaped like tiny stingrays or flounders. Like their larger cousin, the reticulated hillstream loach, they enjoy cleaning off driftwood, scavenging for leftovers, and of course eating algae. 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.

You can order these fish online if you’re unable to locate them at your local fish market. All the best with your nano-tank and have fun in nature.