Congo Tetra Stats InfographicThe Congo Tetra, also known as Phenacogrammus interruptus, is a beautiful, low-maintenance freshwater fish.

It is easy to care for regardless of your level of expertise (beginner or expert aquarist); thus, the Congo Tetra is a great species for you to explore.

Even though this fish is quite easy to care for, it would be a mistake to venture into raising them without the necessary knowledge.

We have put this article together to help you understand everything you need to know about caring for the Congo Tetra. Let’s get started, shall we?

Congo Tetra Stats

Family  Alestiidae
Origin Congo River, Zaire
Average Size 3 to 3.5 inches
Temperament Peaceful, schooling fish
Tank Level Middle and Top level
Diet Omnivores
Breeding Type Egg Layer
Care Level Easy
Recommended Temperature 73 to 82
Recommended pH 6.0 to 6.5
Recommended Hardness 3 to 18 dGH


The Congo Tetra is a popular freshwater species that is revered for its vibrant, eye-catching colors. It was first sighted in 1949; however, because they were difficult for aquarists to breed, they didn’t really catch until the late ’70s.

By this time, Florida Fish farms perfected a breeding line from which most of the specimens in the pet stores descend from. Thanks to this, pet store Congo Tetras have all of the beautiful markings as the Congo tetras in the wild.

Looking at their name, it is easy to deduce that they are endemic to the Congo River Basin. They love murky, slightly acidic water bodies like marshes, tributaries, pools, and streams. Add a bit of tall vegetation, trees, and the right substrate, and the Congo Tetra is in fish lalaland.

– Appearance

Congo tetra also known as phenacogrammus interruptusLooking at the Congo Tetra, it is not hard to see why they are so sought after; their appearance helps them stand out in any aquarium. They have a long and flat-like body that gives them a somewhat compressed look. Their shimmering fins give off a unique rainbow-like appearance.

The exact color of hue you observe depends on how light reflects off this fish’s body; you may see shades of gold, blue, turquoise, and violet. Usually, you notice a stripe that runs along their midsections, from their head to their tail fins. This midsection is composed of color-changing luminescence.

– Sex Identification

There are subtle differences between the male and female species of the Congo Tetra; these differences are known as sexual dimorphism. For the Congo Tetra, the males are slightly bigger than their female counterparts and more colorful with stunning colors.

Also, male Congo Tetras have longer dorsal fins than their female counterparts; the other fins on the males have a wispy appearance that shimmer in the water. Their fins have a slightly purplish hue that is accented by staunch wide edges.

During the Congo Tetra breeding season, the female Congo Tetra takes on a plump, well-rounded appearance because her abdomen is filled with eggs.

– Size

Congo Tetras are on the small side compared to other fish species like the Silver Dollar fish; however, they are still a bit bigger than many other tetras. The average Congo Tetra size is around 3 to 3.5 inches in captivity. However, in the wild, they can grow longer by almost an inch (4.5 inches).

In rare cases, some aquarists have been able to raise Congo Tetras longer than the 3 to 3.5 inches benchmark in captivity. When we studied these aquarists, we found one thing in common, they all raised their fish in tanks far bigger than the minimum tank size recommended. In addition, they had fish with great genetics and a proper diet.

– Sexual Dimorphism

Congo Tetras show slight differences between the sexes; by knowing what to look out for, you can distinguish the males from the females quite easily. The male, for one, is much more colorful than the female Congo Tetra and has a much larger fin structure. In males, the caudal fin is longer, and the dorsal fin is more pronounced.

Female Congo Tetras, on the other hand, are mainly golden with shades of silver and green. Their fins are not as extended and fanciful as those of the male Congo Tetra.

Congo Tetra Breeding

We have listed all that you’ll need to put in place the Congo Tetra care to successfully breed your Congo Tetra fish.

1. Tank Size

You will need an even bigger tank than most tetras to breed the Congo Tetra because they produce many eggs and grow rapidly. We recommend that you use a 15 to 20-gallon long tank for breeding.

2. Substrate Layer

The perfect breeding tank for them should have enough boiled peat moss covering the bottom, reverse osmosis, and several Java moss atop the peat moss.

3. Temperature

The recommended water temperature for breeding Congo Tetra is 77℉.

4. Filtration and Aeration Requirements

Avoid aeration and filtration in the breeding tank as it can disturb the peat moss substrate at the bottom of the water and make the water cloudy.

5. Lighting

Congo Tetras prefer to spawn in dark areas, so you should reduce the amount of light entering their breeding tank. The reduced lighting should be maintained for at least 8 hours prior to spawning.

– Spawning in Congo Tetras

Once they have been properly conditioned for breeding, the female Tetra lays her eggs at the base of the Java moss or on the spawning mops, which provide extra protection for the eggs.

Remove the breeders immediately after the eggs have been laid. They can lay as many as 500 eggs in a single breeding session.

– Caring for Eggs

Congo Tetra eggs take around 5-8 days to hatch after spawning, unlike their South American relatives, whose eggs hatch in a much shorter time frame. After the eggs are hatched, they are fully free-swimming and often ravenous, so you’ll have to organize what they would eat.

The Congo Tetra fry can be fed a diet of infusoria for the first day or two after they hatch; after that, you can switch to baby brine shrimp. Within two weeks of becoming free-swimming, you can now begin to feed them a steady stream of dry, powdered food.

– How Fast Does the Congo Tetra Grow?

Congo tetras grow quickly. It takes the Congo Tetra fry two weeks to reach 1 inch and another 3 months to reach two inches.

At the 3-month mark, you will begin to notice their colors becoming prominent, and at 6 months, the Congo Tetras would have reached a length of 3 inches, their average adult size. A 6-month-old Congo Tetra is ready for breeding and can be moved to the breeding tank.

Average Lifespan

On average, most Congo Tetra will live for a short while, 3 to 5 years in captivity. In rare cases, experienced aquarists have seen their fish live past the 5-year mark, but as we said, it is rare. As with most freshwater tetra fish, you can help the Congo Tetra live a long, happy, and healthy life by paying attention to their diet and environment.

Congo Tetra Care

Congo tetra fishCaring for the freshwater Congo Tetra is relatively easy because you don’t need that much to keep them happy. They are hardy and can survive in a host of water conditions.

However, there is still a need for you to learn about them, their habitats, breeding behavior, temperament, and preferred diet, if you are to have a happy community of the Congo Tetra.

Let us explore what it takes to care for the Congo Tetra.

– Setting Up a Tank

As we have said, caring for the Congo Tetra is fairly easy because they are tough and can withstand variations in environment and water conditions. However, it is crucial that you still pay attention to their needs, and what better way to do this than to set up their tank right.

Setting up a tank for Tetras involves many things. To make it easy for you, we have listed the things you will need to take into account.

1. Tank Size

We recommend a tank of no less than 30 gallons to cater to a group of 6 Congo Tetras. Keeping them in lesser numbers may lead to them becoming very skittish and stressed because they don’t feel protected enough. A downside to them being stressed is that their beautiful colors seem to fade away.

Thus, what you get is nothing like the spectacular hues you are meant to have in your aquarium. So, you should aim for a tank size that gives them enough space to swim and show off their beautiful hues.

2. pH Levels

Congo Tetras are hardy and can tolerate a variety of water pH levels. However, they seem to prefer waters with a slightly acidic pH. Therefore, we recommend that the pH levels in your tank are maintained between 6 – 6.5 for optimum action.

3. Temperature

With a temperature range of 75 to 81℉, you can keep your Congo Tetras happy. To stimulate breeding, you can set up a separate tank with the temperature on the higher side of this range. Use a heater if you are not sure how to maintain the tank temperature within this recommended range.

4. Water Hardness

Looking at the natural habitat of the Congo Tetra in the wild, it is easy to see that they love softer waters. Therefore, in setting up your tank, you must ensure that the water is soft for them to thrive.

5. Filtration

Water quality is crucial to the survival of this fish. Thus, it is important to set up a filter in your tank to remove wastes and nitrates. The filter helps you maintain the pristine conditions in your tank.

You don’t want your fish getting sick because of opportunistic pathogens, now do you? For a start, get a filter with a capacity that is larger than what your tank needs. That way, you are sure it can handle the task of tank filtration adequately.

– What to Add to Your Tank

1. Plants

Besides ensuring the tank size and water quality of your tank are right, you also need to consider what plants to plant in the aquarium. Plants give good cover for your fish and provide a place for them to lay their eggs.

You can go for live plants or even artificial plants; however, we would recommend you select live plants because they help regulate the nitrate levels in the tank.

When planting the tanks, you should leave enough space for your fish to swim around freely. A great suggestion is to put the plants at the back and sides of the tank. That way, your fish still have enough space in the front to swim in.

2. Rocks and Caves

Apart from plants, artificial rocks, caves, and driftwood provide more hiding spots for your Congo tetra. Although they may not spend a lot of time at the bottom of the tank, it is still great to give them something akin to what they have in the river basins in the wild.

Tank Mates

When choosing tank mates, it is important to consider Congo Tetra compatibility. First, you must know that the Congo Tetras are schooling fish and can become anxious if they are kept on their own. Thus, it is vital that you keep them in a group of at least 6 other Congo Tetras.

To keep them with other fish species, you must follow some rules. For example, you must take care to put them with other peaceful fish species of the same size or smaller, if possible. This is because Congo Tetras have a peaceful disposition and can become stressed when placed with more aggressive species. Stress leads to illness.

Avoid any fish that has fin-nipping tendencies because they will destroy the spectacular fin of your male Congo Tetra. Fin nipping also makes your Tetra reserved and stressed; not a good thing for your fish.

The best Congo Tetra tank mates include:

– Tank Mates to Avoid

To help you establish a peaceful and happy community of Congo Tetras, we have listed some of the fish you should avoid.

  • Avoid much larger, more aggressive fish such as sharks, whales, etc., as they can stress your fish.
  • Avoid fish species that are much smaller than the Congo Tetra because the Congo Tetra may nip them.


Congo Tetras are as beautiful as they are timid. Therefore, it is not advisable that you keep them with fish much larger than them to avoid unnecessary aggression. They can be skittish when kept with fast-swimming fish or very aggressive fish species.

This category of fish can stress your Congo Tetra and cause it to become less colorful and ill. Keeping them with the right tank mates can significantly lower their stress levels and make them even more active.

Most times, Congo Tetras prefer to swim at the middle and top layers of the tank. So it is best to keep them with fish that won’t fight them for this preferred swimming space.

Proper Diet

Congo Tetras are omnivores. In their natural habitat, they feed on worms, insects, algae, and plant matter. Thanks to their wide range of diet options, feeding them is not a big task. They love fresh, live, and flake foods as well as blood worms and brine shrimps. A varied diet of insect larvae and vegetables are great additions to their diet.

You can also feed Congo Tetras with commercial foods; however, you must ensure that store-bought food is of high quality. Remember, you can only get the best out of your Tetras if you care for them adequately.

Sometimes, you may find your Congo Tetra nipping at the ends of the leaves in the tank. This is usually an indication that they are not getting enough food. Upping your fish diet at this point is enough to curtail this behavior and nourish your fish.

– Feeding Frequency

The Congo Tetra diet requires feeding tiny bits of food at regular intervals daily. Don’t worry if you observe that they do not come to the food immediately; they can be quite shy about eating when they know they are being watched. However, if you observe that they are not getting enough food, you can try a behavioral feeding ring.


  • Congo tetraCongo Tetras are beautiful schooling fish endemic to the Congo River Basin.
  • They grow rapidly, reaching almost their max size in six months.
  • Congo Tetras thrive in large tanks, with carefully filtered water and dim lights.

With proper care, your Congo Tetra can light up your entire aquarium. Of course, proper care encompasses their diet, tank set-up, breeding, and tank mates. If African Congo Tetras appeal to you, you should go ahead and raise them.

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