Congo Tetra
Phenacogrammus interruptus
A stunning, large schooling fish native to the Congo River basin. Known for their iridescent rainbow colors and active swimming behavior. Despite their size, they are notoriously peaceful and can be skittish, requiring ample swimming space, dim lighting or floating plants, and peaceful tank mates. Avoid keeping with fin-nippers.
Congo Tetra At a Glance
Congo Tetra Tank Requirements
Will Congo Tetra fit in your tank?
Care guides tell you what Congo Tetra needs, the next question is whether your tank can safely provide it. Test Congo Tetra against your tank size, maintenance needs, and the fish you already keep before you buy.
Congo Tetra Water Parameters
Congo Tetra Temperament & Compatibility
Congo Tetra Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Standard (Mixed School)
A standard mixed group of males and females. Congo Tetras are best kept in mixed-sex schools to encourage natural behavior and full male coloration.
Same care requirements as the base species
Also known as: Unsexed, Juvenile
Male
Males are larger, display highly vibrant iridescent colors (blue, red, gold), and develop long, feathery extensions on their dorsal and caudal fins.
Differs in 1 trait from base species
Also known as: Male Congo, Show Male
Female
Females are significantly smaller, with a plumper belly, much shorter fins, and more subdued silvery-gold coloration compared to males.
Differs in 1 trait from base species
Also known as: Female Congo
Albino
A selectively bred albino/platinum morph lacking dark pigments. Males retain some iridescent colors and long finnage, but the body is primarily white/pink.
Differs in 1 trait from base species
Also known as: Albino Congo Tetra, Platinum
Congo Tetra Care Guide Summary
The Congo Tetra, scientifically known as Phenacogrammus interruptus, belongs to the Characins family group. Adults reach a maximum size of approximately 8.5 cm and have a compressed body shape with a moderate growth rate. Classified as peaceful, this species primarily occupies the mid-level and surface zones of the aquarium and produces a low level of biological waste.
To thrive, the Congo Tetra requires a freshwater only aquarium with a minimum volume of 110 litres and a tank length of at least 90 cm. Water temperature should be maintained between 23°C and 28°C, with a pH range of 6–7.5 and a general hardness of 3–18 dGH. A moderate water flow is preferred.
The Congo Tetra is a rewarding species to keep, provided its core environmental needs are met. This species is available in 4 varieties: Standard (Mixed School), Male, Female, and Albino. Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.
Congo Tetra Habitat Setup
When setting up an aquarium for the Congo Tetra, a moderate water flow best suits their natural preferences. Because this species occupies the mid-level and surface zones, the aquarium layout should prioritise adequate surface area with floating cover to make them feel secure near the waterline and open swimming space in the centre of the tank for free movement. Useful additions include dense planting to provide cover, break sightlines, and reduce stress and floating plants to diffuse overhead light and create shaded areas. Keepers should note that a tight-fitting lid is essential, as this species is a known jumper.
Congo Tetra Compatibility Notes
Classified as peaceful, the Congo Tetra is a schooling species that feels most secure in a sizeable group, where natural shoaling behaviour reduces stress and brings out their best colours. Selecting tankmates that favour different water layers from the mid-level and surface zones can help reduce competition and territorial overlap.
Who Congo Tetra Is Actually For
Congo Tetra is best for a fishkeeper who wants a species that can settle into a calmer community setup and can provide a keeper who can commit to a proper group of at least 6. It makes the most sense for a hobbyist who will actually build around its needs, especially plants.
The most common mistake is buying Congo Tetra for looks first and only later discovering how its adult size, behavior, or bioload changes the whole tank plan. Another frequent problem is underestimating its social needs. A token pair or trio often behaves very differently from a real group.
Congo Tetra Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Congo Tetra.
30 Gallon Breeder
40 Gallon Breeder
55 Gallon Standard
60 Gallon Breeder
75 Gallon Standard
90 Gallon Standard
Show 10 more tank sizes
Frequently Asked Questions About Congo Tetra
How big does Congo Tetra get?
Congo Tetra (Phenacogrammus interruptus) typically reaches a maximum adult size of approximately 8.5 cm. They have a compressed body shape and a moderate growth rate.
What tank size does Congo Tetra need?
A minimum aquarium volume of 110 litres and a tank length of at least 90 cm are recommended for Congo Tetra. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Congo Tetra need?
Congo Tetra thrives in freshwater only conditions with a temperature range of 23–28°C, a pH between 6 and 7.5, and a general hardness of 3–18 dGH. A moderate water flow is preferred.
Is Congo Tetra peaceful or aggressive?
Congo Tetra is classified as peaceful with an aggression score of 2 out of 10. They are generally well-suited to peaceful community tanks.
How many Congo Tetra should be kept together?
Congo Tetra is a schooling species and should be kept in groups of at least 6. Larger groups help distribute aggression and encourage natural schooling behaviour.
Does Congo Tetra have any special tank requirements?
Yes. Congo Tetra benefits from plants - densely covered and plants - floating in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Does Congo Tetra need a lid on the tank?
Yes. Congo Tetra is a known jumper, and a tight-fitting lid or cover is essential to prevent escape. Even a small gap can be enough for a determined fish to leap out.
Useful setup supplies
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Guidarium Editorial Desk
Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.
- Last reviewed
- April 28, 2026
- Last updated
- April 28, 2026
- Issues or corrections?
- Contact the editorial team
Top Tank Mates for Congo Tetra
These fish are strong compatibility matches for Congo Tetra based on water preferences, temperament, adult size, and tank behavior.
Trapdoor Snail
Cipangopaludina chinensis
Ideal Tank MatesTandanus Catfish
Tandanus tandanus
Ideal Tank MatesApistogramma Marmor (Marbled Apisto)
Apistogramma erythrura
Ideal Tank MatesGolden Bristlenose Pleco
Ancistrus sp. L144
Ideal Tank MatesMalaysian Trumpet Snail (MTS)
Melanoides tuberculata
Ideal Tank MatesAssassin Snail
Anentome helena
Ideal Tank MatesPlants That Suit Congo Tetra
These plants pair well with Congo Tetra based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
Afzel's Anubias
Anubias afzelii
Amazon Sword
Echinodorus amazonicus
Anacharis
Egeria densa
Anubias Barteri
Anubias barteri
Baby Tears
Lindernia rotundifolia
Balansae
Cryptocoryne crispatula
Fish Similar to Congo Tetra
Long-Finned African Tetra
Brycinus longipinnis
A robust, active schooling fish native to the fast-flowing rivers and streams of West Africa. They are characterized by their striking silver bodies and large, expressive eyes. Due to their size, speed, and energetic nature, they require a spacious aquarium with strong water flow and plenty of horizontal swimming space.
Flag Tetra
Hyphessobrycon heterorhabdus
A peaceful, active schooling fish native to the Amazon basin. It is commonly called the 'Belgian Flag Tetra' due to the distinctive tricolor lateral stripe (black, red, and yellowish-white) running along its side. They are an excellent community fish that thrives in planted aquariums with soft, slightly acidic water. Like most tetras, they must be kept in groups to feel secure and display their best colors.
Bentos Tetra
Hyphessobrycon bentosi
A striking, deep-bodied tetra native to the slow-moving waters of the Amazon basin. Characterized by a reddish-brown tint and a prominent black spot on the dorsal fin, often tipped with white. They are active but peaceful schooling fish. Males will frequently engage in harmless, visually impressive sparring displays to establish hierarchy and impress females.
Cardinal Tetra
Paracheirodon axelrodi
A stunning schooling fish native to the upper Orinoco and Rio Negro basins in South America. Famous for its brilliant iridescent blue line and a vivid red stripe that extends the full length of its body (distinguishing it from the Neon Tetra). They are strictly schooling fish that thrive in warm, acidic blackwater environments.
Lemon Tetra
Hyphessobrycon pulchripinnis
A peaceful, deep-bodied schooling tetra known for its translucent yellow coloration and striking black and yellow fins. They are robust and active, making them an excellent choice for planted community aquariums. Their colors intensify significantly in a well-established tank with a dark substrate and proper schooling numbers.
Serpae Tetra
Hyphessobrycon eques
A striking, deep-red schooling fish known for its highly active nature. While hardy and beautiful, Serpae Tetras are notorious fin-nippers. This behavior is usually localized within their own pecking order if kept in large enough schools (8+), but they should never be housed with slow-moving or long-finned tank mates like Bettas, Angelfish, or Gouramis.



