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
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. They prefer to eat midwater, which is not at the top or bottom of their tank. Therefore, you should look for slow sinking foods like baby brine shrimps, frozen cyclops 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. 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. They look best when there are at least 10 brigittae rasasboras and they are placed in a school with a backdrop of lush green 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. 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. See our care guide for more information about cory catfish care.
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. Additional color options are available in the black kuhli locach (P. ablonga) or silver kuhli loiach (P. andaris). All details can be found in the care guide.
5. Green Neon Tetra
Paracheirodon simulans is a smaller cousin to the neon tetra. It measures approximately 1-1.25 inches (22.5-3 cm) in length and has a very thin 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. 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. Due to the fact that males can be territorial, you should aim for a group of at least one male per 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. For more details, read our article on clown killies.
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 are very hardy and would do well in either a nano tank or as a school of 20-30 fish in a larger tank. Unlike many nano fish, ember tetras are relatively outgoing and eagerly eat from all levels of the aquarium. Feed them floating or slowly sinking foods like Xtreme Nano pellets, Hikari Micro 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). They have striking blue, silver, and black colors and, like most livebearers, breed quite readily.
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 water that is soft, Wonder Shells or Seachem Equrium may be an option. 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 one of our favorite varieties, so make sure to give them a shot. For more information, see our complete guppy care guide.
9. Spotted Blue Eye Rainbowfish
Pseudomugil rainbowfish such as Gertrude’s Rainbowfish are a good choice if you’ve always loved rainbowfish and don’t have the space to keep them. 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. Pseudomugil rainbowfish can be very vibrant and beautiful but they have a shorter life expectancy. To breed them, use dense floating plants like guppygrass or spawning mops made of yarn.
10. Borneo Sucker Loach
Last but not least, we have an algae eater for your nano fish 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. Similar to their bigger cousin, the reticulated Hillstream Loach, they love eating algae and cleaning out driftwood. 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 be territorial and may act in a way that is not normal for their species. You can get one individual or a whole group.
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. All the best with your nano-tank and have fun in nature.