Buenos Aires Tetra 101: Care, Diet, Tank Size, Tank Mates & More

Meta: In this article, we’re going to cover the Buenos Aires Tetra, a fish that used to be in some demand from fish owners across the world. This is a wonderfully bright fish, with a bright red fringe on the underneath of its belly, with an iridescent color to the rest of its body.

If you’ve ever glanced around an aquarium, you might have noticed a small and colorful fish that pops up in a few tanks. This is probably the Buenos Aires Tetra, a very popular addition to most aquariums.

This fish is incredibly social, and you’ll often see more than one congregating in your tank. This one floats around in schools, so you should buy a handful of these to really get your tank looking nice and busy.

These fish also acclimatize well with other breeds, so you won’t have to worry about them eating half your tank.

This is also a very colorful fish, the perfect solution to a drab tank. They have a wonderful color and are very easy to maintain. They can also survive in hard and soft waters, making them one of the most versatile fish on this list.

So where can you find one of these fish? How much does it cost to keep one? What do they feed on? What is the best kind of fish to pair this one with? How many water parameters are there? What decorations can you put in this fish’s tank?

What diseases can these fish get and what can you give them to help get rid of them?

Well, if you want answers to all these fishy questions and more, then we would suggest you keep reading. We have all the info you need to help keep your Buenos Aires Tetra nice and fit and energetic.

Fish can be difficult to take care of at the best of times, so we would recommend you get to know them first before buying some.

Care Guide

Tank Size

This fish can be described as a medium-sized guppy, so we would recommend getting a tank that is at least 30 gallons in size. This way, you can be sure that your fish is getting plenty of room to move around.

If you have a school that is larger than 10, then you will need to increase the size of your tank accordingly.

Tank Mates

This fish is very sociable, so you can house it with a few other breeds. For example, the neon tetra will be a good fish that you can keep in the same tank as the Buenos Aires. You should avoid putting it in a tank with fish that have long fins, as they do tend to nibble at them.

This fish will also pair very well with larger tetras. This fish will also help to relax other fish such as cichlids. You will actually see these more timid fish come out hiding in their caves when they are around these tetras.

Same Species Tanks

You can put this in a tank with plenty of other breeds of fish and they will have a calming effect on these creatures.

Water Parameters

Make sure that you keep the Ph level of this fish at a fairly medium level, anywhere around 5.8 to 8.5. The water hardness should be around 35 dGH, with a temperature between 64 and 82 degrees Fahrenheit.

What To Put In Their Tanks

This fish will thrive in various different climates, and you can put them in heated and unheated tanks. This fish does tend to nibble and eat vegetation, so they might not be suitable for planted tanks.

You can choose very sturdy plants that will be able to withstand the nibbling of these fish. We would recommend Vallisneria and Java fern for this purpose. You can also put rock and driftwood in this tank, as it will give your fish plenty of places to hide.

These fish do like to jump above the surface of the water, so make sure that you have a cover that can be sealed every night. This fish likes plenty of light in the mornings and will get on nicely with plenty of types of substrate.

Common Diseases

This fish is prone to things like skin flukes and parasitic infections. It will also succumb to bacterial infections, which are noticeable as little white flakes on the side of this fish’s gills. You should try and clean this fish’s tank regularly to avoid these infections and diseases.

Another method of avoiding the spread of this kind of infection is also by quarantining your fish when you first buy them. You can do this by putting them each in separate containers before you transfer them into their final tank.

The best way of avoiding disease is making sure that you feed your tetras a very balanced diet and making sure that the tank is cleaned on a regular basis.

Food & Diet

You should make sure that your tetras are fed regularly, as they have quite a healthy appetite. This fish should have a varied and balanced diet as in the wild they are used to eating plants and organic matter.

This creature will normally feed on crustaceans, worms and other insects in the wild. In captivity, you can feed it live, frozen or flake food and it will enjoy it just as much.

As this fish really likes to eat plants, make sure that it has a bit of lettuce to feed on. You can also feed this one spinach, which will give it a nutritious snack.


This fish will live roughly 3 to 5 years in captivity. One thing that will increase this fish’s life is making sure that it has a clean tank and a wide balance of food.


This fish has a wonderful neon coloring, with an iridescent rainbow pattern on its back and a blue/grey color on its belly. The upper fins are blue with red on the lower fins. This fish really will brighten up a tank and a lot of aquarian enthusiasts add them to complement their larger, uni-color fish.


This fish is one of the larger of the small breeds of fish, reaching up to 3 inches at full maturity. This adult will grow to full after roughly 4 months of being born.

Behaviour & Temperament

This fish is extremely sociable and mild-mannered. You can house them with a lot of breeds of fish and not have to worry about them attacking each other. These fish like to be kept in schools of their own species, so we would recommend getting at least 5 Buenos Aires Tetras in your tank at any one time.

If you keep these fish in solitary confinement, you will soon notice a decrease in their movement and a dip in their mood.


This fish is very easy to breed, all you need to do is put a female and a male together. If you have an even number of male and female fish, then you will see roughly the same distribution of genders in the fry. When the female is pregnant, you will notice her belly getting nice and round.

You’ll need to keep the Ph level at a slightly more acidic level to encourage breeding, somewhere around the 6.5 to 7.2 mark. Make sure that the tank is full of sturdy moss so that they can attach their eggs to it. We would recommend Java moss for this purpose.

At first, these animals will lay around 2,000 eggs in the first sitting. You should remove the parents once the eggs have been laid. The adults usually do not look after the children once they have been spawned.

The eggs will hatch after 24 hours of being born, so you will have to act quickly to remove the parents and make sure that they have another tank prepared. After a few days, the fish will have eaten their egg sacs and be fully mobile.

You will need to feed these fry specially bought fry feed, which will be easier for them to consume. Once they get larger, you can feed them brine shrimp and larger morsels of food.

Gender Differences: Male Vs. Female

The male Buenos Aires tetra will develop bright red dorsal and anal fins. The female will be slightly more faint and transparent in coloration. The male is slightly blogger in size than the female.

Fun Facts

  • These fish will generally not eat other fish, although they are omnivorous and will eat insects, worms and smaller zooplankton.
  • These fish are expert jumpers, so you’ll need to make sure that you have a lid on your tank to prevent them from escaping.
  • This hails from the Bueno Aires region, hence the name. They can be found in many regions of South America such as Argentina and Paraguay.
  • In the wild, they are often found in ponds, rivers and streams. They are freshwater fish and cannot survive that long in salt water.