Fantastic Red Congo Tetra (Phenacogrammus sp.)

Add a Fantastic Red Congo Tetra for a shoal of moving colour

The Fantastic Red Congo Tetra is a red, long-finned African tetra of the genus Phenacogrammus, the same genus as the classic Congo Tetra. The fish in our photographs is a deep red-orange from nose to tail, with golden edges to the scales, a brighter red line along the middle of the body, a dark spot at the base of the tail and long, flowing red fins tipped in white. In a group, under good light, they make one of the most eye-catching shoals in freshwater.

Like all Congo tetras, it is a peaceful, active, mid-water fish that grows larger than most tetras and needs a long, well-planted aquarium with open swimming space. It suits a keeper who already manages a stable community tank and wants a centrepiece shoal rather than a beginner's first fish.

Understand what "Fantastic Red" means

Fantastic Red is a trade name. The fish reaches us identified only to genus, as Phenacogrammus sp., and no species has been formally described under that name. We have not found a published account of where this red form comes from, so we cannot tell you whether it is a wild-collected population or a line developed in captivity, and we do not attach a species name to it. What we can say is that it has the shape, finnage and needs of the Congo tetra group, so its care follows the best-documented member of the genus, the Congo Tetra (Phenacogrammus interruptus). FishBase explains the genus name as Greek for "deceptive" and "letter" or "signal".

If you prefer the classic species, see our Congo Tetra or the five-pack of Congo Tetras, and for a pale form the Albino Congo Tetra. All of them are on our Phenacogrammus Congo tetras page.

Know what you receive

One purchase supplies one live Fantastic Red Congo Tetra, unsexed. The listing has a single option rather than graded sizes, so ask us for the current size if it matters. Congo tetras are shoaling fish, so order a group of at least five together. Seriously Fish notes that Congo tetras are often sold as small, drab fish that colour up as they mature, and that the long fins of the males develop with age and good water. The photographs show the colour form; your fish will vary in shade and finnage and may need several weeks in a settled tank to reach full colour.

Our delivery and Live Arrival Guarantee terms explain dispatch days and what to do if there is a problem on arrival. Phenacogrammus appears without exceptions on the government's checklist of freshwater fish that may be kept in indoor aquaria in England and Wales under the general licence, linked from its guidance on non-native fish.

Plan a long tank for an 8–10 cm adult

Congo tetras are big tetras. Because this form is not identified to species, we use the range of the genus to plan the adult size:

So plan for adults of 8–10 cm, males larger than females, in an aquarium at least 100–120 cm long. Seriously Fish adds that young fish can be kept in smaller tanks while they grow. Our guide to the best fish for a 100-litre tank and our stocking calculator help you work out how many fit alongside other fish.

Lay out an African-style planted tank

Seriously Fish suggests an African biotope with driftwood branches, floating plants and Anubias, and says the fish show their best colour in any well-planted tank with plenty of open swimming space. A darker floor and some floating cover make the red stand out, and a large shoal lit from the front and above, especially by daylight, is at its most striking.

Match the water and keep it clean

Seriously Fish describes slightly acidic, soft water with good circulation as ideal, and both main sources accept a broad range. Where they differ, the table shows both.

A target of 24–26°C and pH 6.5–7.0 sits inside every source's range. UK tap water differs a lot between regions, so test yours and read our water chemistry guide before deciding whether to soften it. Seriously Fish warns that Congo tetras are sensitive to water quality and that poor conditions spoil the males' fins and cause colour loss, which matters even more in a fish bought for its colour.

Size the filter and keep a routine

Seriously Fish recommends a filter turning the water over four to five times an hour. OATA asks for a 25% water change at least weekly, dechlorinated replacement water and filter media rinsed in old tank water rather than under the tap. Test ammonia, nitrite, nitrate and pH every week, and more often while the shoal is new.

Feed for colour, once a day

FishBase records that wild Congo Tetras eat worms, small insects, crustaceans and plant matter, and Seriously Fish describes an unfussy omnivore that also takes algae and zooplankton. Seriously Fish advises making live and frozen foods a good part of the diet to bring out the colour. OATA's rule for tetras is to feed once a day, only what they eat within a few minutes.

From our range, colour-enhancing flakes, frozen daphnia, frozen mysis, live bloodworm and spirulina flakes cover all of these.

Introduce the shoal calmly

Congo tetras are nervous on arrival. Seriously Fish describes them as easily frightened, especially in small numbers, so introduce the whole group together. OATA's method: lights off, float the sealed bag for 10 minutes, add small amounts of tank water over up to 20 minutes, then net the fish across and discard the bag water. Our acclimatisation guide shows each step.

Keep the lights low for the rest of the day and feed sparingly for the first few days. Expect the shoal to stay near cover at first and to move into open water as it settles. Watch for clamped fins or a fish that stays apart, and test the water every couple of days during the first week.

Choose calm tank mates

Seriously Fish calls the Congo tetra peaceful and suitable for most community tanks, but notes that its active swimming and adult size can scare very shy species, while its own shy nature means boisterous tank mates are a poor choice. Never keep it with fin-nippers, which damage the males' long fins. Keep a mixed-sex shoal so the males display to each other.

Decide with this table

Those suggestions follow Seriously Fish. Our kribensis guide covers the classic African partner, and the tank mates tool checks any other mix. See more shoals in our schooling fish collection.

Watch for health problems early

Healthy Congo tetras hold their fins open, swim as a loose group in mid-water and feed eagerly. OATA's warning signs include clamped fins, flicking against decor, shimmying, white spots, fluffy growths, rapid breathing, faded colour and loss of appetite. Ragged fins in males usually point to fin-nipping tank mates or poor water. In almost every case the first step is to test the water and carry out a partial water change, then seek advice before medicating.

Sex and breed Congo tetras

Seriously Fish says males are larger and much more colourful, with extended tail filaments and a greatly extended dorsal fin; OATA also notes the males' longer fins. Aquarium Glaser cautions, for the related P. aurantiacus, that sexing is uncertain except with large males, so a bigger group gives the best chance of both sexes.

The Congo Tetra is an egg-scatterer, described by Seriously Fish as "not easy but possible". Breeders condition the best male and a plump female on live and frozen foods, then spawn them in a small tank with a mesh base, subdued light, plant clumps and soft water below neutral. A female may lay up to 300 large eggs over several days, 100–200 being more usual; many fungus in the first 24–48 hours. Eggs hatch in about six days (FishBase and Seriously Fish), and the fry take infusoria at first, then brine shrimp nauplii or microworm after two or three days. No breeding report exists for the Fantastic Red form itself.

Browse the rest of our African tetras and our wider tetras collection for more shoaling fish.

Answer Fantastic Red Congo Tetra buying questions

What is a Fantastic Red Congo Tetra?

It is a red Congo tetra sold under the trade name Fantastic Red and identified only to genus, as Phenacogrammus sp. No species has been formally described under that name, and we have not found a published account of its origin, so we do not claim a species name for it. It has the shape, long fins and care needs of the Congo tetra group.

How big does it grow?

Plan for 8-10 cm. In the genus, FishBase records 8.0 cm total length for male Congo Tetras (6.0 cm for females) and 10.0 cm for Phenacogrammus aurantiacus; Seriously Fish gives 80 mm standard length for the Congo Tetra. Males are larger than females.

What size tank does it need?

A tank at least 100-120 cm long. FishBase gives a minimum aquarium length of 100 cm for Congo Tetras and Seriously Fish a base of 120 x 30 cm, about 108 litres, for adults. OATA gives at least 80 litres for tetras of 5 cm and over.

How many should I keep?

At least five, as FishBase and OATA advise, in a mixed group of males and females. Congo tetras are easily frightened when kept in small numbers, so a group of six to ten looks better and behaves more confidently.

What water does it need?

Soft to moderately hard, slightly acidic to neutral water at 23-28 C. Seriously Fish gives pH 6.0-7.5 and 3-18 dGH; FishBase gives 23-26 C, pH 6.0-8.0 and dH 5-19. Most important is clean, stable water: poor conditions spoil the males' fins and colour.

What does it eat?

It is an omnivore. Feed a good flake or small granule once a day, with frozen or live foods such as daphnia, mysis and bloodworm several times a week to bring out the red, and some plant-based food such as spirulina flakes or algae wafers.

Which fish can live with it?

Peaceful fish that are not too small or too shy: other medium tetras, rainbowfish, Corydoras, Bristlenose plecos, Synodontis and peaceful dwarf cichlids such as kribensis. Avoid fin-nippers and boisterous fish.

Will my fish look exactly like the photographs?

The photographs show the colour form. Congo tetras often arrive smaller and paler than adults and colour up as they mature, and the long fins of males develop with age and good water. Individual fish vary.

Consult the care references

• Seriously Fish: Phenacogrammus interruptus: the Congo Tetra, the best-documented Phenacogrammus: size, aquarium size, layout, water values, filtration, diet, tank mates, sexing, breeding and sensitivity to water quality.
• FishBase: Phenacogrammus interruptus: the Congo Tetra: author and year, male and female maximum lengths, water ranges, wild diet, egg numbers and hatching time, group size and IUCN status.
• FishBase: Phenacogrammus aurantiacus: Phenacogrammus aurantiacus: author and year, distribution in the Kouilou, Ogowe and Congo basins, maximum length, the broad band along the flank and IUCN status.
• Aquarium Glaser: Phenacogrammus aurantiacus: Phenacogrammus aurantiacus in the trade (29 February 2016): the name Golden Congo Tetra, origin, import size and how difficult sexing is.
• OATA: How to look after tetras and pencilfish: UK care sheet for tetras: adult sizes, tank sizes, group size, water values for captive-bred fish, maintenance, feeding, tank mates, acclimatisation, health signs and breeding.
• gov.uk: Introduce or keep non-native fish and shellfish: UK government guidance on keeping non-native fish, updated 15 October 2026.
• gov.uk: Freshwater fish that can be kept for ornamental, scientific research or conservation purposes (checklist V7): the government checklist of freshwater fish genera that may be kept in indoor aquaria in England and Wales under the general licence (V7, last updated 13 October 2026).
• Tropical Fish Co delivery policy: current dispatch days and Live Arrival Guarantee terms.