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Red Eye Tetra Care Guide

Red Eye Tetra Care Guide

Red eye tetras can infuse a touch of elegance into any aquarium setting. Their striking appearance, and easy-going, active nature make them a joy to watch.

This shimmering freshwater species is native to South America, known for its metallic body and striking red eyes.

This article will cover everything from understanding their natural habitat, diet preferences, and ideal tank conditions to health issues and breeding practices.

Key Takeaways

  • Red eye tetras are colorful, social fish that love to swim in groups. They need a large tank and get along with other peaceful fish.
  • These fishes eat various foods like flake food, granules, and veggies. Proper food helps them stay healthy and active.
  • They can live up to five years if taken care of properly. This means maintaining good water quality and watching out for common diseases.
  • Male and female Red eye Tetras look different. Males have brighter colors while females are larger with rounded bodies due to carrying eggs.

Red Eye Tetra Overview & Natural Habitat

Red eye tetras, scientifically known as Moenkhausia sanctaefilomenae, are popular freshwater fish originating from South America. They thrive in clear river habitats and enjoy the cover of dense vegetation found in areas like the Amazon River basin.

  • Common name: Red Eye Tetra
  • Scientific name: Moenkhausia sanctaefilomenae
  • Care level: Easy
  • Size: 2.75 inches (7 cm)
  • Lifespan: 3 – 5 years
  • Temperament: Peaceful
  • Diet: Omnivore
  • Group size: Groups of 6
  • Minimum tank size: 20 gallons (75 liters)
  • Tank level: Middle dweller
  • Water temperature: 72°F to 84°F (22°C to 28°C)
  • Water pH levels: 5.5 to 8.5
  • Water hardness: 4 to 8 KH

In their native habitat, these lively fish often swim among a backdrop of dark substrates coupled with dim lighting conditions – elements that mimic the tannin-stained waters they frequent.

Over time, red eye tetras have also become extensively bred in Asia for aquarium enthusiasts worldwide as adaptable species suitable for a variety of water conditions. Whether it’s hard alkaline or soft acidic environments, these tetras have remarkable resilience.

This adaptability coupled with their striking appearance makes them a sought-after option for home aquariums. Their preferred settings usually include plenty of plant cover to offer ample hiding spaces and emulate their natural environment.

Appearance & Size

Red eye tetras are distinctive for their vibrant, metallic silver bodies offset by a bold, red circle around their eyes and a black vertical stripe on their tail. Usually reaching an average size of 2.75 inches (7 cm), they feature semi-transparent fins with black and white edging that gracefully contrast with their gleaming scales.

Difference Between Males & Females

Distinguishing between males and females is fairly simple. Females appear slightly larger with more rounded abdomens than their male counterparts.

This noticeable difference is primarily due to their role in carrying eggs. In contrast, males typically have a slimmer body.

Among these freshwater fish species, color variations provide another key indicator for differentiating genders. Male red eye tetras often boast brighter colors compared to the less intense hues on female bodies – an attribute thought to attract females during mating seasons.

Personality & Behavior

Red eye tetras have a charming social disposition. They are peaceful fish, making them ideal for community tanks filled with similar-sized fish. Red eyes are schooling fish so they play well in groups and show their best behavior when they swim together in a school of six or more.

These tetras are active swimmers and predominantly occupy the middle and top sections of the tank. They have an innate curiosity to explore every nook and cranny, giving your aquarium life during viewing hours.

Their energetic nature might cause slight disturbances to less active or slow-moving top-dwelling species. Although being naturally peaceful, they can get territorial during feeding times and with smaller fish. I have a friend who went to their aquarium to find his red eye tetra swimming around with a little green neon tetra in its mouth.

Average Lifespan

In a well-maintained aquarium, these eye-catching fish can live up to five years. This lifespan makes them ideal for novice and seasoned aquarists alike as their long lives offer ample opportunity to observe and appreciate the interesting behaviors and bright colors that are characteristic of this species.

Regular water changes, balanced diet, and close monitoring help ensure they achieve this potential lifespan in captivity.

Red Eye Tetra Care

Red eye tetra Care involves understanding their natural habitat, providing a balanced diet, ensuring adequate tank conditions, and regularly monitoring their health to prevent common diseases.

Tank Size

The red eye tetra, being a relatively larger species among tetras, needs ample swimming space. The recommended tank size for these active fish is a minimum of 20 gallons. A larger aquarium not only provides sufficient room but also contributes to the overall health and longevity of red eye tetras by reducing stress levels.

In an ideal scenario, you may consider allocating around two gallons of water per single adult red eye tetra. This means that a fully stocked 20-gallon aquarium could comfortably house up to ten adult fish without overcrowding.

However, if you plan on introducing other species or additional numbers of the same species into your tank setup, increase your aquarium size accordingly to support the well-being of all tank mates.

Water Parameters

  • Water temperature: 72°F to 84°F (22°C to 28°C)
  • Water pH levels: 5.5 to 8.5
  • Water hardness: 4 to 8 KH

An advantage of having these tetras is their adaptability to different water conditions. This means you don’t have to invest a lot of time in maintaining specific temperature, water pH, and water hardness levels. Staying within the recommended parameters is sufficient for their care.

Red eye tetras thrive in water with a temperature range of 72°F to 84°F, with an ideal range around 79 to 80°F. Keep the pH levels within the 5.5 to 8.5 range, while aiming for a neutral 7.0 pH. Additionally, a water hardness level of 4 to 8 KH is optimal for their health. 

However, during breeding times, they prefer slightly more specific parameters – a little acidity and very soft water help create an ideal environment for their eggs. Make sure to get yourself a reliable water test kit to ensure your readings are accurate.

What To Put In The Tank

When setting up your tank, it’s crucial to consider replicating the red eye tetras’ natural habitat for their well-being. These tetras originate from the clear, slow-moving waters of South America.


A dark-colored substrate is ideal as it mirrors their natural riverbed habitat, which is often filled with detritus and decaying leaves, giving the riverbed a nearly black appearance.

Ideal Plants & Decorations

I recommend setting up your tank with live plants as their natural habitat is densely populated with aquatic plants. Some suitable choices include Java Fern, Anubias Nana, Amazon Sword Plant, or the Water Wisteria as they are hardy and can tolerate a little nibbling. Just make sure you allow them enough room to swim freely.

Driftwood also works well for hiding spots, combined with rocks to create areas of shade. Avoid using sharp or rough decorations that could potentially injure your fish while they explore their surroundings.

Type of Filter

For these tetras, a hang-on-back or canister filter is recommended due to its effectiveness in maintaining ideal water conditions.

These filters provide good flow and superior filtration without creating too much current that could stress the fish. Since red eye tetras aren’t the best swimmers, they prefer calm water with low currents.

Ideal Tank Mates

Red eye tetras, being peaceful freshwater fish, cohabitate well with a variety of other tropical species. Their ideal tank mates include similarly sized and temperamental fish such as Guppies, larger types of Rasboras, Swordtails, and Dwarf Gouramis.

Active schooling fish like zebra danios also make good companions because they share similar water conditions and feeding habits.

Aggressive or larger predatory fish should be avoided as they could harm your red eye tetra.

Red Eye Tetra Food & Diet

Red eye Tetras are omnivores, so they love to consume a variety of foods. You can feed your tetras various types of meat like live, frozen, or freeze-dried options such as bloodworms, brine shrimp, Daphnia, and tubifex worms. They also enjoy blanched spinach, peas, or cucumbers as vegetables.

These tetras have a big appetite so you’ll want to feed them two to three times a day to keep them happy. Only give them what they can consume in three meals to prevent overeating and water contamination.

Breeding Red Eye Tetra

Breeding red eye tetras isn’t overly difficult, you will want to breed them in even groups e.g. 6 males and 6 females.

Begin by isolating the males and females for approximately one week. During this time, feed them plenty of live, protein-rich foods to help prepare them for breeding.

Next, you’ll want to prepare your breeding tank, I recommend a capacity of around 20 gallons. Ensure that the water conditions in this tank closely resemble those in the standard tank, with slightly a warmer temperature.

Ensure that your breeding tank has dim lighting, plenty of plant cover, and suitable hiding spaces for the eggs. Red eye tetras have a tendency to eat their eggs shortly after the female deposits them. Floating aquarium plants like Java Moss can be an effective solution to protect the eggs. Mosses have little tendrils that the eggs can easily stick to, and their branched stems provide effective camouflage from predators.

When your breeding tank is ready, transfer your conditioned fish into the tank. If you transfer them in the evening, you should notice the breeding process in the morning.

When you notice the eggs have been laid, remove the adult fish from the tank and let the eggs incubate, this should take around a day or two. Early on you’ll want to feed the fry Daphnia or powdered fry food.  As they get bigger you can start to give them brine shrimp and other commercial foods.

Common Health Issues

Like many freshwater fish, red eye tetras are susceptible to several common health problems. Ich, also known as “white spot disease,” is among the most frequent issues these fish encounter.

The disease manifests in small white spots that cover the entire body of the fish, giving them a grainy appearance. It’s caused by a parasite and can be harmful if not treated promptly.

Another common health problem for red eye tetras is fin rot—a bacterial or fungal infection that causes fins to deteriorate over time. This condition often results from poor water conditions or injury, leading to ragged and decaying fins which may turn white at the edges.

In addition to these diseases, there are other risks like dropsy and swim bladder disease which can affect red eye tetras. Dropsy leads to swelling due to fluid retention while swim bladder issues cause buoyancy problems making swimming difficult for infected fish.

All these health challenges emphasize the critical importance of maintaining proper water quality in your aquarium for healthy red eye tetra care.

Are Red Eye Tetras Right For You?

Red eye tetras make a colorful addition to any freshwater aquarium. They are admired for their metallic body and trademark vibrant red eyes. These fish don’t require much care, making them a great choice for both seasoned aquarists and those new to the hobby.

Although they can live peacefully with other small fish species, they are best when placed in groups of at least six due to their schooling nature. Remember that these fish also love exploring tanks teeming with plant life where they can play and hide when they need to.

Wrapping Up

Caring for red eye tetras introduces fish keepers to a fascinating species. These active freshwater dwellers offer dazzling displays in dimly lit tanks, especially with dark substrate and live plants.

They’re not just attractive but also robust as they thrive across a range of water conditions. If you provide these beautiful fish with the attention they require, you’ll have no difficulty helping them flourish.

I’m Elle, the founder of FishHQ. I created this website to share knowledge, tips, and inspiration for beginner hobbyists to help them create a healthy, happy, and vibrant environment for their fish to thrive. Read more...