Ruby Tetra: Care, Tank Size, Food, Lifespan & More!

If you’ve been thinking about adding a new member to your underwater family, the Ruby Tetra might be the perfect fit for your aquarium. These vibrant and active fish can quickly become the highlight of your tank and are relatively easy-to-care-for fish. From details on tank size and diet to lifespan and compatibility with other fish, we’ve got you covered in everything Ruby Tetra. So, dive in and discover why these small but stunning beauties are a favorite among hobbyist aquarists.

Definition of Ruby Tetra

The Ruby Tetra, also known as Axelrodia Riesei, is a beautiful freshwater fish that adds a vibrant pop of color to any aquarium. They are shoaling species, meaning they prefer to be kept in a group of at least six fish. Ruby Tetras are relatively new to the aquarium trade, having been discovered in 1988 in the upper part of the Rio Meta in Colombia. They are exclusive to this area and less widespread than other tetra species.

Appearance and Size

These fish are small and grow up to 1.6 inches in length. The fins are mostly transparent, but if you look closely, you might notice subtle streaks of iridescent blue on the tips. As for the body, it’s a vibrant shade of orange-red, except for a small black spot on the tailfin. The color becomes paler towards the belly.

Average lifespan

The average lifespan of Ruby Tetras ranges, they can live up to 3 to 5 years even longer, but this depends on how well they are being taken care of. The quality of care provided plays a significant role in their potential lifespan.

By providing top-notch care, including proper nutrition, ideal tank conditions, and a stress-free environment, you can increase your chances of your Ruby Tetras living long and healthy lives. These little gems are a joy to have in your aquarium!

Care for Ruby Tetra


Ideal water conditions

It is important to provide them with ideal water conditions to ensure the best care for your Ruby Tetras These fish thrive in warm waters with slight acidity, mimicking their natural habitat in the upper part of Rio Meta in Colombia. Aim for a temperature range of 68°F to 82.4°F and a pH level between 5.0 and 7.0. Maintaining stable ammonia, nitrite, and nitrate levels is also crucial.

Consider using a blackwater setup with a dark or tea-colored tint to replicate their natural habitat. By creating these optimal water conditions, you can ensure the health and well-being of your Ruby Tetras.

Ammonia and nitrate levels

Maintaining appropriate ammonia and nitrate levels is essential for the health of Ruby Tetras. These fish are sensitive to changes in water quality, and high levels of ammonia and nitrate can be harmful to them. To ensure a safe environment for your Ruby Tetras, it is important to monitor and control these levels regularly.

Monitoring the pH levels frequently and using a pH test kit can help you ensure that the conditions are stable and suitable for your Ruby Tetras.  Keeping the ammonia level at 0 ppm and the nitrate level at a low level will contribute to the overall well-being of your fish.

Water changes and maintenance

Maintaining a clean and healthy environment for your Ruby Tetras is crucial to their well-being. Regular water changes and maintenance are necessary to ensure their longevity. It is recommended to perform weekly water changes to remove any organic waste build-up and maintain stable water parameters.

Pay attention to their water temperature, pH level, and ammonia and nitrate levels to ensure they are within the ideal range for Ruby Tetras. Providing a clean and well-maintained habitat can help your Ruby Tetras thrive and live a happy and healthy life.

Tank requirements

When it comes to tank requirements for Ruby Tetras, there are a few key factors to keep in mind – first, the tank size. Even though Ruby Tetras are quite small, a 10-gallon or bigger aquarium is required. This is because they are schooling fish and need to be housed in a group of at least 6. Providing a larger tank will also allow you to add other non-aggressive fish species as tank mates, creating a harmonious aquatic community.

Next, the filtration system is important to maintain the water quality. Ruby Tetras also prefer dimly lit environments, so having some plants in the tank can help create the ideal lighting conditions. Overall, providing a comfortable and suitable tank environment is crucial for the well-being of these beautiful fish.

Filtration system

The filtration system is an important consideration. These fish prefer slow-moving or stagnant water, so a powerful filtration system with filtering materials that increase acidity is desirable. Soft water conditions are crucial for their well-being, and maintaining stable water parameters is key to their health.


it’s important to consider their lighting needs. These fish prefer dimly lit environments, which can be easily achieved by incorporating floating plants. This setup provides the desired lighting conditions and creates a natural and comfortable environment for these small and delicate fish.

By mimicking their natural habitat, you’ll be able to showcase the stunning colors of the Ruby Tetras while ensuring their well-being and happiness in your aquarium.

Plants and decorations

Regarding plants and decorations for your Ruby Tetra tank, you have plenty of options to create a beautiful and natural environment. Start using a sand substrate to mimic the silt and mud in their natural habitat. Add some driftwood and smooth rocks for a natural look.

You can also incorporate live plants, such as Java fern or Anubias, to provide hiding places and create a lively atmosphere. Leave plenty of open space for swimming, but make sure to include enough plants for your Ruby Tetras to explore and feel secure.


When considering tankmates for Ruby Tetras, it’s important to keep their small size and peaceful nature in mind. These fish do best when surrounded by others of their own species, so keeping them in a group of at least six individuals is recommended.

Other small, peaceful fish can also make compatible tankmates, such as small rasboras, danios, or guppies. However, avoiding larger or aggressive fish that may see the Ruby Tetras as prey is important. Providing a peaceful community environment ensures that your Ruby Tetras thrive and exhibit their unique behaviors.

Feeding your Ruby Tetra

Types of food

Ruby Tetras, are not picky eaters. In their natural environment, they feed mainly on small invertebrates and insects. In an aquarium, they will readily accept dry or freeze-dried food as long as it is suitable for their small mouth size. Providing them with a varied and balanced diet for optimal health and vibrant colors is important. You can supplement their diet with live or frozen foods such as artemia, microworms, tubifex and baby brine.

Feeding schedule

Feed your Ruby Tetras several times a day, but be careful not to overfeed them. Feeding them 2-3 times a day and providing enough food that they can eat in about two minutes will prevent overfeeding and keep water quality under control.

Breeding of Ruby Tetra

Breeding Ruby Tetras can be challenging, as they don’t breed very frequently in captivity. However, with the right conditions and care, successful breeding is possible. These fish are sexually dimorphic, with females being slightly larger and plumper than males.

It’s best to transfer the parents to a separate breeding tank a few days before mating and remove them afterward to ensure the survival of the eggs. The tiny fry hatch within 2-3 days and require microscopic food such as infusoria. The fry should be kept in a separate tank for at least a month to ensure their safety.

Common health problems of Ruby Tetra


Ruby Tetras are a stunning species of Tetras, but they require a bit more attention than some other freshwater fish.  their selective habitat in the wild means they haven’t quite adapted to tolerate a wide range of water parameters and temperatures like some other fish have.

Just like any other fish out there, Ruby Tetras can be affected by a variety of ailments. These can include Ich, skin flukes, bacterial infections, and parasitic infections. So, it’s important to keep an eye on your little aquatic friends and give them the care they need.

Signs of illness

If you have a fish with small, white spots on its skin and gills so, it could be a sign of Ich, a parasitic disease that is highly contagious. If left untreated, it can spread throughout the fish’s body and even infect all of its tank mates.

Another disease to be aware of is Neon Tetra Disease, which also causes white spots on the fish’s body, but they are larger than those caused by Ich. However, this disease is not as common as Ich, so if you notice white spots on your fish, it’s more likely to be Ich. It’s important to monitor your fish closely and take action at the first signs of illness.

Causes of common health problems

Various factors can cause common health problems in Ruby Tetras. Poor water quality, such as high levels of ammonia, nitrites, or nitrates, can stress the fish and make them susceptible to diseases. Fluctuations in temperature or pH levels can also negatively impact their health. Additionally, stress from overcrowding or aggressive tankmates can lead to illness.

An inadequate diet or lack of proper nutrition can weaken their immune system, making them more prone to infections.

Prevention and treatment

It’s crucial to maintain stable water parameters and provide top-notch care to prevent common aquatic diseases. Regular water changes, proper filtration, and monitoring ammonia and nitrate levels are key. If your fish show signs of illness, such as Ich or bacterial infections, quarantine them and use over-the-counter medications for treatment.

Remember, a varied and balanced diet and a clean and healthy aquarium environment can greatly reduce the chances of health problems and promote the long and vibrant life of your Ruby Tetras.

Final Thoughts and Recommendations

In conclusion, Ruby Tetras is a beautiful and fascinating addition to any freshwater aquarium. Their vibrant colors and shoaling behavior make them a joy to observe. Ruby Tetras can live a long and healthy life with proper care and attention to their specific needs, such as ideal water conditions and tank requirements.

It is recommended to keep them in groups of at least six fish and provide a well-decorated tank with plants and hiding spaces. Remember to feed them a varied diet and monitor their health to ensure their well-being. Overall, Ruby Tetras are a delightful choice for any aquarist.