Buenos Aires Tetra 101: The Complete Care Guide

Buenos Aires Tetras are a wonder and beginner-friendly freshwater fish. This species is quite active (making them fun to watch), easy to care for, and quite pretty as well!

But just because these fish are relatively low-maintenance, it doesn’t mean you can get away with a subpar understanding of their care requirements. This is a trap that many owners fall into with “easy” fish, and it always backfires.

This guide will teach you the fundamentals of proper Buenos Aires Tetra care. You’ll be completely prepared for ownership by the time you’re done reading it!

Species Summary

Feisty and energetic, the Buenos Aires Tetra (scientific name: Hyphessobrycon anisitsi) is a freshwater species that will add plenty of life to your aquarium.

Generally undemanding and easy to care for, these fish are perfect for newer aquarists and seasoned ones looking to add some color to their tank.

The Buenos Aires Tetra is native to Argentina. It can be found in the Río de la Plata and its various connecting rivers, lakes, and streams. Originally discovered in 1907, this colorful freshwater fish has been a big part of the aquarium trade for over six decades.

While their popularity is undeniable, some aquarists aren’t too fond of them due to some unique behavioral quirks (more on that later). However, you can easily work around those issues and enjoy everything the Buenos Aires Tetra has to offer.


On average, the lifespan of a Buenos Aires Tetra is between three and five years.

To help your fish reach the upper limits of that lifespan range, you must provide optimal care on a consistent basis.

Like any other fish species, these tetras can experience stress and illness due to inadequate living conditions. When kept in a poorly maintained tank, these fish will have a much shorter life expectancy.


Buenos Aires Tetras has a similar shape to other types of tetras. However, their coloration is what sets them apart.

The body is predominantly silver. However, a thin stripe of blue extends from behind the gill plate down to the caudal fin. In the right lighting conditions, this line will shimmer a spectrum of different colors.

One Buenos Aires Tetra in a freshwater tank

On the base of the tail fin, you’ll notice a distinct diamond-shaped black mark. It extends into the fork of the tail fin and usually stretches to meet that blue midline.

The caudal, pectoral, and anal fins take on a reddish-orange hue. Meanwhile, the dorsal fin is typically transparent. You might see a streak of black or red on some specimens.

Author Note: Generally, males have more vivid coloration than females. However, the female Buenos Aires Tetra us usually a bit bigger and has a broader overall shape.

Average Size

These are one of the larger species in the Tetra family. When fully grown, the average Buenos Aries Tetra size is around 2.8 inches in length.

If you want to maximize their size and growth it’s important to purchase them from a well-respected seller and keep them in optimal conditions during their youth. This has the added benefit of providing more color to your tank!

Buenos Aries Tetra Care

Buenos Aries Tetra care is a very easy process (no matter how much experience you have). They adapt well to life in captivity and will not fret over minor fluctuations in their environment.

However, you still need to be vigilant about taking care of their basic needs! These fish can be a challenge if you don’t create the right environment for their lifestyle.

Here are some important care guidelines to follow:

Tank Size

The appropriate tank size for these fish will depend on how many you intend to keep in your aquarium.

Some aquarists have seen success keeping a handful of Buenos Aires Tetras in small 10-gallon tanks. However, we recommend keeping them in an aquarium that can hold at least 30 gallons.

Here’s why:

These are active schooling fish that need ample room to swim around and explore. Keeping them in a cramped tank will only exacerbate behavioral issues and make it more difficult to maintain good water conditions.

Author Note: If you want to keep Buenos Aires Tetras as part of a multi-species community tank, you’ll need to get an even bigger aquarium. Factor in the tank size needs of the other species in your tank and add that to the 30-gallon starting point to come up with your ideal number.

Water Parameters

The best way to keep your Buenos Aires Tetras in good shape is to replicate the warm and soft water conditions of their natural habitat in Argentina.

Fortunately, this is pretty easy to do in most aquariums. This species can tolerate a pretty wide range of temperatures. As a result, they can thrive in both heated and unheated aquariums (making them a good cold water fish).

Stick to the following water parameters and your fish should do just fine:

  • Water temperature: Between 64°F and 82°F (aim for the middle of this range)
  • pH levels: 5.5 to 8.5 (Neutral pH is best)
  • Water hardness: 12 to 35 dGH

Even though Buenos Aires Tetras are hardy and forgiving when it comes to water parameters, it’s still important to perform regular water tests. Get a reliable test kit and check on the conditions of your tank once a week (once it’s established) to make sure no subtle changes take you by surprise.

What To Put In Their Tank

Here’s where things can get a bit tricky for some aquarists. Buenos Aires Tetras aren’t super picky about the types of decorations that you put in their environment.

However, they do have a reputation for tearing up plants!

The go-to for many fish enthusiasts is to create a planted tank due to the aesthetic and water benefits they bring.

But that isn’t the best option for these fish. They will devour pretty much any plant they can get ahold of. Some specimens will not harm Java Fern, but there are no guarantees!

This means if you want plants in the habitat, you’ll need to use artificial ones.

On the plus side, you can get as creative as you want with everything else. Choose either gravel or sand as your substrate. Then, implement driftwood, rocks, caves, or even plastic decorations.

Buenos Aires Tetras won’t care either way!

Beyond decorations, it’s important to utilize a powerful filtration system. Buenos Aires Tetras are sensitive to ammonia, nitrates, and phosphates. So, you’ll need a filtration system that can keep those levels undetectable.

Author Note: It’s a good idea to get a secure lid. These fish are fully capable of jumping out of the water and onto your floor!

Common Possible Diseases

You don’t have to worry about any special diseases with your Buenos Aires Tetras. However, you will need to keep an eye out for common health issues.

These fish are susceptible to Ich, skin flukes, parasitic infestations, and bacterial disease.

In most cases, you can avoid all of those ailments by keeping the tank in good shape. Fish become more susceptible to disease when experiencing stress from poor water conditions.

Because Buenos Aires Tetras are so sensitive to ammonia and nitrate issues, it’s a good idea to perform frequent water changes. You should replace up to 50 percent of the water every other week to keep conditions in tip-top shape.

This is one of those practices that’s easy to skip. But remember, it’s one of the most effective ways to keep your fish healthy!

Food & Diet

Buenos Aires Tetras are more than eager to eat anything you provide!

These fish are natural omnivores. In the wild, their diet mainly consists of plants, insects, and crustaceans.

A varied diet is best in captivity if you want to keep them as healthy as possible. You can provide a standard dry flake or pellet food as their main source of nutrients.

However, high-protein snacks and leafy greens should be given to them periodically as well.

These fish love greens like lettuce and spinach. They also enjoy live, frozen, or freeze-dried snacks. You can provide bloodworms, daphnia, or brine shrimp.

Author Note: It’s best to feed these fish three small meals a day. Provide only enough food for them to eat in about three minutes during each feeding.

Behavior & Temperament

This species does fine in community tanks. However, they need to stay in groups of at least six fish.

When kept alone, they are more likely to be aggressive towards smaller fish.

Buenos Aires Tetras can be bullies to more vulnerable tank mates, so keep an eye out on their behavior. They’re also known to nip at long-finned fish, such as bettas or angelfish.

In a group, these fish are rather active and will often spend their days darting throughout the tank. You might see them playing in plants as well. As mentioned earlier, they will occasionally eat live plants. Stick with artificial plants to avoid any issues.

Buenos Aries Tank Mates

Beyond other fish of the same species, the best Buenos Aires Tetra tank mates are going to be bigger or similar-sized fish. They should not be kept with smaller fish that they can bully. The same goes for slow-moving fish with long fins.

They do well with other large Tetras. Many aquarists even use them as dither fish to help non-aggressive Cichlids feel a bit more relaxed in the environment!

If you want to create a multi-species tank, here are some good tank mates for the Buenos Aires Tetra:

Author Note: If you have enough room in your tank you can also keep Buenos Aires Tetras with various types of snails and freshwater shrimp. To play it safe, get ones that are a bit on the large side.


Buenos Aires Tetras are one of the easier fish species to breed. They’re prolific egg scatterers that can lay as many as 2,000 eggs at once!

If you’re looking to breed these fish, it’s best to create a separate breeding tank with slightly acidic water. This will minimize threats from other fish in a community tank. Use a sponge filter to keep the baby fish safe and add plenty of sturdy plants for the eggs to stick to.

You can spawn the fish in pairs or groups. After adding the fish into the tank, condition them with high-quality live foods. The females will swell up with eggs.

Usually, these fish spawn at dawn. When they do, they will deposit the eggs on the plants.

Remove the adult fish after they have spawned. Buenos Aires Tetras don’t exhibit any parental instincts and will eat the babies when they hatch.

Make sure to act fast! Eggs only take about 24 hours to hatch. The babies will live off of their egg sac for about four days before they become free-swimming. You can then provide infusoria, powdered spirulina, or baby brine shrimp.

Closing Thoughts

Buenos Aires Tetras are fantastic pets that anyone can keep. It doesn’t matter if you’re a total beginner or an experienced aquarist, you’ll enjoy keeping this species in your home tank.

We hope you enjoyed this guide and have decided to consider getting this fish. Honestly, we can’t recommend them enough!

If there are any topics we didn’t cover in this guide we’re always happy to lend a hand. Just pass along your question through our contact form and we’ll respond as soon as possible.

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