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Flag Tetra (Hyphessobrycon Heterorhabdus) Care Guide

Feature Image by AV AquaVISie

If you are asking about the ideal fish that you can add to your home aquarium, then your experts might recommend you flag tetra on their list.

This fish type is beautiful, peaceful, and easy to care for and breed. It can be a great choice for the mates for the community fish tanks. It sounds like a great deal for you, doesn’t it?

Well, if you want to amplify the appeal of your community tank, then flag tetras are your fail-proof option. It is easy to care for this peaceful tetra so that you can do it even if you have just started your hobby as an aquarist.

On this occasion, I’ll cover everything you need to know about this fish. We’ll go into detail about its tank setup, diet, feeding, tank mates, and the breeding guide.

Species Overview

Level of CareEasy
AppearanceElongated body with lateral stripes in black, yellow and red. The pattern resembles the Brazilian flag
Life Expectancy3 to 5  years
Size1.3 – 1.5 inches
Tank Size70 Litres
Tank EnvironmentAn environment with a fast water flow, dark substrate, live plants
Tank MatesOther fish with similar size and peaceful characteristics.

The flag tetra’s scientific name is hyphessobricon heterorhabdus. This fish is so unique because its body pattern resembles the Belgium flag.

At a glance, when you are looking into their bodies, it resembles the latter flag. It is also interesting to know that the species is a native of Northern East Brazil.

The fish can be found in the creeks, ponds, floodplains, as well as tributaries around the local area.


The Flag tetra is a peaceful species with a long, slender olive body that is sometimes silverish. There are stripes of red, black, and yellow across its body. The females tend to be bigger than the males.

This fish is categorized as a shoal fish. You can easily add this fish to the community tank. However, these buddies can survive longer than the other tank mates, who are also similar in size.

To ensure that you can give them the best care as their pet owner, you will want to mimic the natural habitat to be as close as possible to its origin.

Tank Requirements & Setup

The tank requirements are not complex. Since your flag tetras are used to living in particular places, like creeks, floodplains, ponds, etc, it can be simple to replicate the condition.

First things first, you will want to tweak the environment to provide ample shade and mature vegetation. Clearwater is a must so that the fish can be healthy and active on a daily basis. The fish is a schooling creature. It takes effort to prepare your aquarium so that the fish can accept their new habitat.

Tank Size

As mentioned, these tetras are doing their activities in school. Keeping them in a group in your aquarium will be the top priority. You want to make sure that the tank measurements are adequate for them to live, including their tank mates. They need more space to swim and explore.

Thanks to the size of the fish, even 10 gallons of water is enough to cater to a small group of tetras. But if you plan to add more tank mates and beautify your aquascape, you will need to prepare a larger tank to start your rodeo. The tank size will also depend on the number of total specimens you want to add to your tank.

The fish tank size should be good enough to make your pets more comfortable conducting their routine activities and living with their tank mates.

Unfavorable aquarium conditions will come with inconveniences for your fish. It will also make it harder to care for them maximally. That is why you need to set up a fish tank that can support their lives.


When it comes to the filter system, you will need to install a filter that can provide a water flow level of at least four times the volume of the fish tank.


If you live in a four-season country, you will need to install a heater for the winter months. If not, your fish won’t survive the coldness of the season. Make sure to add the aquarium thermometer as well to track the temperature levels in your aquarium.

After installing the filter and heater, you need to pour in the tap water. As you probably know, the tap water itself is not ready to accommodate your pets.

You will need to get the water ready first before proceeding. Switch on the filter and heater and let them cycle for a few days before adding your flag tetras and their tank mates. Some people use a 5-day cycle because it is a common rule to follow. But to be sure, you could extend the maturity cycle to 10 days. It is better to be ready than not.

Water Conditions

The water conditions will be the key to your fish’s survivability and longevity. There are some water parameters that you will want to follow to make sure that they will be up and healthy.

The ammonia and nitrite levels should be lower than zero. Keep in mind that this fish is docile. Even slight changes in nitrates can make them faint. The nitrates must be under 20ppm.

The temperature of the water should be around 20 to 25° Celsius. The pH level should be around 5.5 to 7. Meanwhile, the water hardness can be light to moderate.

The gentle current is the ideal water condition for the fish. Make sure that your filter can provide a stable flow level to the tank community space. Since it is a tiny fish that you are about to care for, consider picking a filter that won’t suck your fish.

Maintaining the water quality will be one of the keys to caring for your tetra to the max. The water change should be at least 20%, which you can do every two weeks. But if you add more tank mates to your larger aquarium, you might need to do the water cleaning more frequently.

Clean the filter regularly. Remove dead plants if they are not wanted. Also, check on the overgrown plants as well.


The decoration is also a crucial part of caring for the flag tetras at your home. It is a method you can use to mimic the real habitat of the fish so that they will feel at home when added to your community fish tank. You can choose these important objects when décorating the tank for your tetras:

  • Dried leaves litter the litter
  • River sand substrate
  • Driftwood
  • Algae magnet
  • Floating plants
  • Dim lighting

To make them look vibrant in your aquarium, you could replicate the black water for the particular species of fish.

Tank Mates

The flag tetras can live peacefully with the other tank mates in the aquarium. It is a school where they will do most of their activities in groups. They can survive much longer by shoaling as a group of a minimum of six individuals or more.

You will want to focus on the tank mates that are similar in size to them. The larger fish are out of the option because they can eat your tetras.

Their compatible tank mates are:

Your little buddies won’t survive alone. They will have good moods and morals when doing everything together with their schoolmates.

Security for your fish is a top priority. That’s why you don’t want to add other fish that could threaten their lives.

But don’t add too many tank mates to your aquascape since this will distress them. You can also add invertebrates and snails to serve as natural cleaners of your community tank. Snails are also indifferent towards other fish.

Food & Diet

It is an omnivorous fish so you can give it anything. But their favorite foods are small invertebrates, larvae, as well as blood worms.

You can also give them plant-based foods like pellets, flakes, etc., but they won’t get bored with the live foods. Frozen foods can also be a consideration if you don’t have a stock of live foods at home. Provide a good mix of diets so that they won’t get bored with your offers.

You should feed them once or twice a day. Overfeeding your fish will make them sick and obese.

Breeding Guidelines

The flag tetras care is easy. But breeding them in captivity is a hard thing to do. You will need to set the correct environment in your tank to trigger the spawning.

It is much better to prepare a dedicated tank for breeding. After spawning, you will want to take the males back to the main tank since they tend to eat their fry.

You can move the kids back to the main tank when they reach a similar size to an adult. Consider getting help from your experts if you are not sure about the breeding process.


Tetras are easily found in both American and African territories. But most of the species in captivity are sourced from the Amazon basin and river systems in South America, precisely the northeast of Brazil.

It has been a common favorite for many aquarists across the globe because of its easy care in captivity. The availability is also reliable. You can find the fish in any nearby pet store in your location.

The unique species is easy to care for, but it will provide certain challenges for the owners to breed them. We will explain this point later in the breeding guidelines section.