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
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. 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. 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
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. You will see a change in their coloration six months after they are born if you take care of them and 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
The 1-inch (2.5 cm) pygmy corydoras are incredibly adorable because they always stay the size of baby cory catfish. 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 enjoy eating just about any fish food, including sinking wafers and Repashy gel food. 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. For more info on how to care for cory catfish, see our care guide.
4. Kuhli Loach
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. Kuhli loaches are a great beginner fish since they are not picky when it comes to water parameters and food preferences. You can also check out the silver kuhli loaf (P. anguillaris) for additional color options. You can read all about them in the full care guide here.
5. Green Neon Tetra
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. Its body is covered in a bright, blue-green horizontal stripe, which shines brilliantly even at night. They can be raised in acidic water but they are able to thrive in the standard parameters of 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. 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. You can give them floating foods like freeze-dried tubifexworms and flakes and they will begin spawning and scattering eggs. Our article on clowns is full of more information.
7. Ember Tetra
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. Feast them with floating or slowly sinking foods such as Hikari Micro Pellets, Xtreme Nano Pellets, and frozen Daphnia.
8. Panda Guppy
Finally, we have a livebearer (or fish that bears live 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 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). These guppies are striking in their blue, silver and black colors. They also breed very easily, just like other livebearers.
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 are a favorite variety, so be sure to give them another chance. You can find more information in our complete guide to guppy caring.
9. Spotted Blue Eye Rainbowfish
If you have always loved rainbowfish but don’t have a tank big enough for them, try Pseudomugil rainbowfish like Gertrude’s rainbowfish. This lovely, 1.5-inch (3.5 cm) species has a yellow or light blue body (depending on its native region), black spots, and bright blue eyes. 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. Like the guppies, they do prefer higher pH and GH, but can live in a very wide temperature range.
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
The last but not the least, we offer an algae eater for your nano tank. The Gastromyzon genus consists of hillstream loaches that usually stay 2 inches (5 cm) in length and are shaped like miniature stingrays or 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.
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.