Blue tetra Care Guide: Diet, Tank Mates, Diseases, Breeding & More

Updated: December 17, 2022

The blue tetra (Aphyocharax paraguayensis) is a peaceful, hardy fish that’s perfect for beginner aquarists.

This little characin is a beautiful blue color with a slight iridescent sheen, and it’s a very active swimmer. It’s also very easy to care for, making it a great choice for first-time fishkeepers.

In this guide, we’ll teach you everything you need to know about blue tetra care. You’ll learn about their diet, habitat, tank mates, and more!

Species overview

The blue tetra (scientific name: Paracheirodon innesi) is a freshwater fish that’s native to the warm waters of South America. In the wild, they can be found in countries like Peru, Brazil, and Colombia.

They prefer slow-moving rivers and streams that have a lot of vegetation. This provides them with plenty of places to hide and feel safe.

The blue tetra is a very peaceful fish that does well in community tanks. They are compatible with a wide variety of tank mates and get along well with other peaceful fish.

The main draw of the blue tetra is its beautiful blue coloration. This makes them a popular choice for freshwater aquariums.


Blue tetra

The blue tetra (or as they’re sometimes called, the diamond tetra) is an eye-catching little freshwater fish. These guys are a beautiful blue color that can sometimes look a little more like green.

This color is very even all over their bodies and really makes their fins pop. The fins on a blue tetra are all clear and very thin.

Their dorsal and anal fins are both short and start about two-thirds of the way back on their bodies. The caudal fin is forked and slightly taller than their dorsal fin.

The most unique thing about the blue tetra is their eyes. These little guys have bright red eyes that stand out against their blue bodies.

Their bodies are long and thin with a slightly rounded belly. This gives them a torpedo-like shape that helps them zip around the tank with ease.


Blue tetras have a lifespan of 5 to 8 years. However, in captivity, they often only live for 2 to 3 years.

The main reason for this is that they’re very sensitive to changes in their environment. Even small changes can cause stress which can lead to illness and early death.

You can help your blue tetra live a long and healthy life by providing them with a stable environment and good water quality.


The Blue Tetra (Paracheirodon innesi) is a small freshwater fish that only reaches a maximum length of about 1.5 inches (4 cm).


Tank Size

The recommended tank size for blue tetras is at least 20 gallons. If you’re planning on keeping a school of these fish, you should add an additional 2 to 4 gallons of water for each additional fish.

While 20 gallons is the minimum, we recommend a slightly larger tank if you can accommodate it. The extra space will give the fish more room to swim and explore their environment.

Water Parameters

The blue tetra (Paracheirodon innesi) is a peaceful, schooling fish that hails from the Amazon Basin. In the wild, they inhabit slow-moving waters with plenty of vegetation.

To replicate this environment in your aquarium, you’ll need to maintain some specific water parameters.

First and foremost, the water needs to be warm. Blue tetras prefer temperatures between 75 and 82 degrees Fahrenheit. They can survive in cooler water but won’t thrive.

The pH should be on the acidic side, between 6.0 and 7.0. Water hardness can be anywhere from soft to hard, but tetras prefer it on the softer side.

Finally, you need to make sure the water is well-oxygenated. Blue tetras are not demanding in terms of filtration, but they do need a good quality air stone to keep the water moving and aerated.

  • Water Temperature: 75 to 82 degrees Fahrenheit
  • pH Levels: 6.0 to 7.0
  • Water Hardness: Soft to hard
  • Alkalinity Levels: Not critical

What To Put In Their Tank

If you’re looking to set up an aquarium that will really show off your blue tetras, then you need to focus on two things; color and movement.

When it comes to the color, you want to go with something that will make the blues in your fish really “pop”. A white or pale gravel substrate is a great choice.

As for the movement, you want to create an environment that has a moderate water flow. This will help keep your fish healthy and also make them look their best.

In terms of decorations, there are a lot of different ways you can go. Some aquarists prefer a more natural look while others prefer a more “aquascaped” appearance.

If you’re going for a natural look, then rocks, driftwood, and plants are always a good choice. If you want something a little more aquascaped, then you can go with things like caves, tunnels, and artificial plants.

No matter what you choose, just make sure that you don’t go overboard. Too many decorations will make it difficult for your fish to swim and could cause stress.

Common Diseases

The blue tetra is a hardy and durable fish, but that doesn’t mean they can’t get sick. There are a few common diseases that can affect this species, but the most common one is ich.

Ich is a very common parasite that can become quite serious if it’s not dealt with. The most obvious sign of this disease is the series of white spots that will begin to cover the body of your fish.

There are plenty of other potential diseases that can affect this species as well, but they’re not as common.

Another thing to look out for is infection from cuts. The most common cause of this is keeping your blue tetra in a tank with a rough substrate (or aggressive species that want to fight).

In general, the best way to prevent these fish from getting sick is to maintain the quality of the water in their tank. A tank with clean and stable water conditions always leads to healthier fish who are more resistant to disease.

Behavior & Temperament

The blue tetra (Paracheirodon innesi) is a peaceful, shoaling fish that does best in a group of six or more. It is a hardy fish that is easy to care for, making it a good choice for beginner aquarists.

Blue tetras are active fish that enjoy swimming in open areas of the tank. They are not fin nippers, but they may chase other small, fast-moving fish. They are not aggressive, but they may nip at the fins of slower-moving fish.

Blue tetras are omnivores and will eat a variety of foods, including flakes, pellets, freeze-dried foods, and live foods.

Tank Mates

The blue tetra is a peaceful freshwater fish that does well in community tanks. These fish are social creatures that prefer to live in groups. In the wild, they can be found in schools of hundreds of fish.

In the home aquarium, a group of at least six blue tetras is ideal. This gives them the safety in numbers they crave while also allowing them to form bonds with their tank mates.

When it comes to choosing blue tetra tank mates, you have plenty of options. These fish are compatible with most peaceful fish species. Some good choices include:


The Blue Tetra is a beautiful little freshwater fish that is popular among aquarium enthusiasts. They are relatively easy to care for and breed, making them a great choice for beginner aquarists.

To breed Blue Tetras, you will need a breeding tank that is at least 10 gallons in size. The tank should be well-filtered and have a soft, sandy substrate. Live plants are also recommended, as they will provide cover for the fry.

The water temperature should be between 75 and 80 degrees Fahrenheit. The pH should be between 6.0 and 7.0, and the water hardness should be between 5 and 10 dH.

When setting up the breeding tank, it is important to remember that Blue Tetras are very timid fish. They will need plenty of hiding places to feel comfortable. Driftwood, caves, and live plants are all good options.

You will also need to purchase a group of at least 6 fish. It is best to have 2 males for every female. The fish should be around the same size and age, and they should all be healthy.

To trigger spawning, you will need to perform a large water change. This will simulate the rainy season in the Blue Tetra’s natural habitat.

After the water change, the fish will start to spawn. The female will lay her eggs in a hiding place, and the male will fertilize them.

The eggs will hatch in 24-48 hours, and the fry will be free-swimming a few days after that.

The fry are very small and will need to be fed live foods. Baby brine shrimp are a good option.

As the fry grow, you can start to introduce them to flake food.


Blue Tetras are a great option for beginner fishkeepers and those looking for a beautiful, low-maintenance fish.

While they are peaceful and get along well with other community fish, they can be shy and may need some time to adjust to their new tank mates and surroundings.

Overall, we think they make a great addition to any freshwater community tank and would recommend them to anyone looking for a pretty, low-maintenance fish!