Phoenix Tetra Care Guide: Tank Setup, Diet, Tank Mates & More

Table of Contents

• Key Takeaways
• Species Overview
• Classification
• Origin & Natural Habitat
• Appearance & Identification
• Average Size & Lifespan
• Care Guide
• Tank Mates
• Food & Diet
• Breeding & Reproduction
• Common Health Issues
• Common Mistakes to Avoid
• Where to Buy
• Frequently Asked Questions
• Closing Thoughts
• Recommended Video
• References

The Phoenix Tetra is one of those species that makes you wonder why it isn’t more popular. With warm orange and red coloration, a peaceful temperament, and males that develop those distinctive elongated dorsal fin filaments, this little Brazilian tetra has a lot going for it. It’s been available in the hobby since it was formally described in 2006, but it still flies under the radar compared to the usual suspects like neons and cardinals.

What really sets the Phoenix Tetra apart is how it looks in a planted tank. The warm tones pop against green plants and dark substrate, and a group of mature males displaying those trailing dorsal filaments is genuinely striking. If you’re looking for a tetra that’s easy to keep but brings something different to the table, this species deserves a serious look. Here’s everything you need to know.

Key Takeaways

• Peaceful community fish with warm orange-red coloration that looks stunning in planted setups
• Males develop extended dorsal fin filaments, making them one of the more visually interesting small tetras
• Minimum group of 6, but 8 to 10 brings out better color and natural behavior
• 15 gallons minimum for a small school, 20+ gallons is ideal
• Easy to moderate care level with a wide range of acceptable water parameters (pH 5.5 to 7.5)
• Not the same as the Flame Tetra (Hyphessobrycon flammeus), despite similar common names

Species Overview

Field	Details
Scientific Name	Hemigrammus filamentosus
Common Names	Phoenix Tetra, Flame Tetra (not to be confused with Hyphessobrycon flammeus)
Family	Acestrorhamphidae
Origin	Rio Araguaia basin, Brazil
Care Level	Easy to Moderate
Temperament	Peaceful
Diet	Omnivore
Tank Level	Mid
Maximum Size	1.4 inches (3.5 cm)
Minimum Tank Size	15 gallons (57 liters)
Temperature	72-82°F (22-28°C)
pH	5.5-7.5
Hardness	2-15 dGH
Lifespan	3-5 years in captivity
Breeding	Egg scatterer
Breeding Difficulty	Moderate
Compatibility	Community
OK for Planted Tanks?	Yes

Classification

Taxonomic Level	Classification
Order	Characiformes
Family	Acestrorhamphidae (reclassified from Characidae, Melo et al. 2024)
Subfamily	Pristellinae
Genus	Hemigrammus
Species	H. filamentosus (Faria & Melo, 2006)

The Phoenix Tetra was formally described in 2006 by Faria and Melo, making it a relatively recent addition to science and the aquarium hobby. The species name “filamentosus” refers to the elongated dorsal fin filaments that develop in mature males.

Note on reclassification: In 2024, a major phylogenomic study (Melo et al.) reorganized the traditional family Characidae into four separate families. The genus Hemigrammus was moved into the newly established family Acestrorhamphidae under the subfamily Pristellinae. Some older references and databases may still list this species under Characidae.

Origin & Natural Habitat

The Phoenix Tetra is native to the Rio Araguaia basin in Brazil, part of the larger Tocantins-Araguaia drainage system within the Amazon basin. This is a region of slow-moving tributaries, flooded forest margins, and seasonal wetlands where the water ranges from clear to tannin-stained depending on the time of year.

In its natural habitat, this species is found in areas with soft, slightly acidic water, dense aquatic vegetation, and a substrate covered in leaf litter and organic debris. The relatively wide parameter tolerance (pH 5.5 to 7.5) reflects the seasonal variability of these Amazonian waterways. Understanding this environment helps explain why the Phoenix Tetra adapts well to planted aquariums with moderate lighting and some tannin presence.

Appearance & Identification

The Phoenix Tetra is a compact, nicely proportioned little fish with a warm orange to reddish body color that intensifies in well-maintained conditions. The fins pick up this same warm tone, and in prime condition the overall effect is a soft, glowing warmth that really stands out against green plants and dark substrates.

The defining feature of this species is the extended dorsal fin filament that mature males develop. This elongated dorsal ray trails behind the body and gives the fish a refined, almost ornamental look. It’s the trait that inspired both the species name (“filamentosus”) and the common name “Phoenix Tetra,” as the flowing filament and fiery coloration together evoke the image of a mythical phoenix.

Body coloration ranges from a translucent amber to deep orange-red, with males typically showing more intensity. The scales may have a subtle iridescent quality under good lighting. The fins are generally warm-toned, and the caudal fin may show hints of red.

Male vs. Female

Sexual dimorphism is noticeable in mature Phoenix Tetras, which is helpful for hobbyists interested in breeding:

• Males: Slimmer body, more intense orange-red coloration, and the distinctive elongated dorsal fin filament. The extended dorsal ray is the easiest way to identify males.
• Females: Fuller-bodied (especially when carrying eggs), slightly more subdued coloration, and a standard-length dorsal fin without the trailing filament.

The differences become more obvious as the fish mature. Juvenile Phoenix Tetras can be difficult to sex, but once males start developing those filaments, there’s no mistaking them.

Average Size & Lifespan

Phoenix Tetras are a small species, reaching a maximum size of about 1.4 inches (3.5 cm) in total length. They’re on the smaller end of the tetra spectrum, similar in size to ember tetras and slightly smaller than neons.

With proper care, stable water conditions, and a varied diet, expect a lifespan of 3 to 5 years. This is typical for small characins. Consistent water quality and a stress-free environment (proper group size, appropriate tankmates) are the biggest factors in reaching the upper end of that range.

Care Guide

Tank Size

A 15-gallon tank is the minimum for a school of 6 to 8 Phoenix Tetras. For a larger group of 10 or more (which is when they really look their best), go with 20 gallons or bigger. These are mid-level swimmers that appreciate having room to school and display, even though they’re not particularly fast or active compared to some tetra species.

Water Parameters

Parameter	Ideal Range
Temperature	72-82°F (22-28°C)
pH	5.5-7.5
General Hardness	2-15 dGH
KH	1-10 dKH
Ammonia / Nitrite	0 ppm
Nitrate	Below 30 ppm

One of the nice things about the Phoenix Tetra is its relatively wide parameter tolerance. It handles a pH range from 5.5 up to 7.5, which means it can work in soft acidic setups as well as more neutral community tanks. That said, the best coloration tends to show in softer, slightly acidic water with some tannin presence.

Weekly water changes of 20 to 25 percent keep things stable. Avoid sudden parameter swings, especially with temperature. Consistency matters more than hitting a perfect number.

Filtration & Water Flow

Standard sponge or hang-on-back filtration works well for Phoenix Tetras. They come from slower-moving waters, so avoid creating a strong current in the tank. If your filter output is too powerful, use a spray bar or baffle to diffuse the flow. A gentle current is fine and helps with oxygenation, but these aren’t fish that enjoy swimming against heavy water movement.

Lighting

Moderate lighting works best. The Phoenix Tetra’s warm orange coloration actually looks more vivid under subdued light than under intense illumination. If you’re running strong plant lights, floating plants can help create shaded areas where these fish feel more comfortable and show their best colors.

Plants & Decorations

This is a species that looks fantastic in a planted tank, and it’s also completely plant-safe. Use a mix of background stems, midground plants like crypts or anubias, and floating plants to create a natural, layered look. Driftwood and dried leaf litter add tannins that bring out the fish’s warm tones while providing visual cover.

Leave open swimming space in the center and front of the tank. A well-planted perimeter with an open swimming lane is the classic layout that works perfectly for small schooling tetras like this one.

Substrate

A dark substrate is the way to go with Phoenix Tetras. Black sand or fine dark gravel will make that warm orange coloration pop. Light-colored substrates tend to wash out the color on most tetra species, and Phoenix Tetras are no exception. If you’re running a planted tank, a quality aquasoil doubles as both a plant-friendly substrate and an attractive dark background for the fish.

Tank Mates

Phoenix Tetras are peaceful and easygoing, making them a solid choice for community tanks. They won’t bother other fish and generally keep to themselves, schooling in the mid-level of the tank. The key is pairing them with species that share the same calm temperament.

Best Tank Mates

• Other small, peaceful tetras (ember tetras, cardinal tetras, pristella tetras)
• Rasboras (harlequin rasboras, chili rasboras, lambchop rasboras)
• Corydoras catfish (any species)
• Otocinclus and small bristlenose plecos
• Dwarf cichlids (Apistogramma, German blue rams)
• Small gouramis (honey gouramis, sparkling gouramis)
• Cherry shrimp and amano shrimp
• Nerite snails, mystery snails

Tank Mates to Avoid

• Large or aggressive cichlids (oscars, Jack Dempseys, African cichlids)
• Fast, nippy species like tiger barbs or serpae tetras
• Any fish large enough to view them as food
• Highly territorial bottom dwellers in small tanks

Because of their small size (1.4 inches), be thoughtful about what you pair them with. Even semi-aggressive species can push Phoenix Tetras around and cause chronic stress.

Food & Diet

Feeding Phoenix Tetras is simple and straightforward. They’re omnivores that accept a wide range of foods without any fuss. In the wild, their diet consists of small invertebrates, insect larvae, algae, and plant matter.

In the aquarium, provide a varied diet for the best health and color development:

• Staple: High-quality micro pellets or crushed flakes
• Frozen foods: Bloodworms, daphnia, brine shrimp, cyclops
• Live foods: Baby brine shrimp, microworms, daphnia (excellent for color enhancement)
• Supplements: Spirulina-based flakes, freeze-dried tubifex

Feed small amounts two to three times per day. These are small fish with small mouths, so make sure food particles are appropriately sized. Crushed flakes and micro pellets work better than standard-size pellets. Live and frozen foods fed a few times per week will noticeably improve coloration, especially in males.

Breeding & Reproduction

Phoenix Tetras are egg scatterers that can be bred in captivity with some planning. The difficulty level is moderate, in line with most Hemigrammus species. It’s not as simple as livebearers, but experienced hobbyists shouldn’t have much trouble.

Breeding Difficulty

Moderate. You’ll need a dedicated breeding setup and some patience, but it’s very achievable for hobbyists with basic breeding experience. The biggest challenge is raising the tiny fry through the first couple of weeks.

Spawning Tank Setup

• Breeding tank: 10 gallons is sufficient
• Decor: Fine-leaved plants (java moss, spawning mops) to catch scattered eggs
• Substrate: Bare bottom or a mesh grid raised above the bottom to protect eggs from being eaten
• Filtration: Gentle sponge filter only
• Lighting: Very dim, or cover the tank sides to reduce light

Water Conditions for Breeding

• Temperature: 78-82°F (26-28°C), slightly warmer than normal
• pH: 5.5-6.5 (soft and acidic is best for triggering spawning)
• Hardness: 2-5 dGH (soft water)

Using RO or very soft water mixed with a bit of peat extract or Indian almond leaves helps create the right conditions. A gradual drop in pH and increase in temperature can help trigger spawning behavior.

Conditioning & Spawning

Condition a pair or small group with high-protein foods (live or frozen brine shrimp, daphnia, bloodworms) for one to two weeks before moving them to the breeding tank. Introduce the conditioned fish in the evening. Spawning typically occurs in the early morning hours, with the female scattering adhesive eggs among fine-leaved plants or spawning mops.

Egg & Fry Care

Remove the adults immediately after spawning. Like most egg-scattering tetras, Phoenix Tetras will readily eat their own eggs if given the chance. The eggs are light-sensitive, so keep the breeding tank dim or covered.

Eggs typically hatch within 24 to 36 hours. The fry become free-swimming 3 to 4 days after hatching. Initial feeding should be infusoria or liquid fry food, transitioning to freshly hatched baby brine shrimp once the fry are large enough to take them (usually around day 7 to 10). Growth is slow at first, but steady once they start accepting brine shrimp.

Common Health Issues

Phoenix Tetras are reasonably hardy fish, but like all small characins, they’re vulnerable to a handful of common diseases. Most health problems are preventable with proper care.

Ich (White Spot Disease)

The most common ailment in freshwater fish, period. It usually shows up after temperature swings or the stress of shipping and acclimation. Look for white spots resembling grains of salt on the body and fins. Raise the temperature to 86°F (30°C) gradually and treat with a quality ich medication.

Fin Rot

Bacterial infection that causes the edges of the fins to become ragged and discolored. It’s almost always a water quality problem. Increase water change frequency and treat with an antibacterial medication if it doesn’t improve on its own.

Neon Tetra Disease

Despite the name, this affects many small tetra species, not just neons. It’s caused by the parasite Pleistophora hyphessobryconis and is unfortunately incurable. Symptoms include loss of coloration, difficulty swimming, and a wasting appearance. Quarantining all new arrivals for 2 to 4 weeks is the best prevention.

Stress-Related Illness

Keeping Phoenix Tetras in groups that are too small, with overly aggressive tankmates, or in unstable water conditions will lead to chronic stress. Stressed fish are far more susceptible to disease. Maintain a proper school size (6+), stable parameters, and calm tankmates.

Common Mistakes to Avoid

• Keeping too few: A group of 3 or 4 won’t school properly, won’t display well, and will be stressed. Get at least 6, ideally 8 to 10.
• Confusing with the Flame Tetra: The Phoenix Tetra (Hemigrammus filamentosus) and the Flame Tetra (Hyphessobrycon flammeus) are completely different species. Make sure you know what you’re buying.
• Bright lighting with no cover: These fish show better color and feel more secure with moderate to subdued lighting. Floating plants help if you need strong light for other plants.
• Overpowering filtration: They prefer gentle water flow. A canister filter blasting current across the tank will stress them out.
• Skipping quarantine: Small tetras are notorious for carrying diseases into established tanks. Always quarantine new arrivals for at least 2 weeks.
• Light-colored substrate: You’ll lose half the visual impact. A dark substrate makes a world of difference with this species.

Where to Buy

The Phoenix Tetra is still relatively uncommon in the mainstream hobby, so you may not find it at your local big-box pet store. Specialty retailers and online fish stores are your best bet. Check these trusted sources:

• Flip Aquatics
• Dan’s Fish

Since availability can be hit or miss, it’s worth signing up for stock notifications if they don’t have them when you check. When you do find them, buy the full group you need at once rather than adding individuals over time. A single purchase means less acclimation stress and a group that settles in together.

Frequently Asked Questions

Is the Phoenix Tetra the same as the Flame Tetra?

No, they are completely different species. The Phoenix Tetra is Hemigrammus filamentosus, while the Flame Tetra is Hyphessobrycon flammeus. They belong to different genera and come from different regions of South America. The Flame Tetra has been in the hobby much longer (described in 1924), while the Phoenix Tetra was only formally described in 2006. The confusion comes from overlapping common names, so always check the scientific name when purchasing.

Are Phoenix Tetras good for beginners?

Yes, with some caveats. They’re peaceful, hardy, and accept a wide range of water parameters. The “easy to moderate” care level comes from the fact that they do best in soft to neutral water, and getting the best coloration requires some attention to diet and tank setup. But they’re not demanding fish by any stretch. A beginner with a properly cycled tank and stable parameters should have no issues.

How many Phoenix Tetras should I keep?

A minimum of 6, but 8 to 10 is better. Larger groups are more confident, display more natural schooling behavior, and you’ll see more intense coloration from the males as they compete for attention. In a group of 10+, watching the males flash their dorsal filaments is one of the highlights of keeping this species.

Do Phoenix Tetras nip fins?

No. Phoenix Tetras are among the more peaceful tetra species and are not known for fin nipping. They’re safe to keep with long-finned species like bettas, fancy guppies, and angelfish (though angelfish may pose a predation risk due to size difference).

What makes the Phoenix Tetra’s dorsal fin so distinctive?

Mature males develop an elongated dorsal fin ray that extends well beyond the normal fin margin, creating a trailing filament. This is the trait that gives the species its scientific name (“filamentosus”). It’s used in courtship displays and is one of the most eye-catching features of this fish. Females do not develop this filament, which makes sexing adult Phoenix Tetras relatively straightforward.

Can Phoenix Tetras live with shrimp?

Yes. Adult cherry shrimp and amano shrimp are generally safe with Phoenix Tetras. However, like most small tetras, they may eat tiny shrimplets if they find them. If you’re trying to breed shrimp in the same tank, provide plenty of moss and dense plant cover where shrimplets can hide.

Closing Thoughts

The Phoenix Tetra is the kind of fish that rewards patience and attention. It might not grab your attention the way a flashy neon or cardinal does on a store shelf, but give a school of these time to settle into a well-planted tank with dark substrate and moderate lighting, and you’ll see why it has a growing fanbase. Those warm orange tones and the trailing dorsal filaments on the males create a display that’s hard to beat at this size.

It’s also just an easy fish to live with. Peaceful, adaptable, and undemanding about food. If you’ve been looking for something that’s a step off the beaten path without requiring specialized care, the Phoenix Tetra is well worth tracking down. With over 25 years in this hobby, I can tell you that the species you have to hunt for a little are often the ones you end up appreciating the most.

Recommended Video

Check out our tetra tier list video where we rank the most popular tetras in the hobby, including the Phoenix Tetra:

References

• Froese, R. and D. Pauly, Eds. FishBase. Hemigrammus filamentosus. Accessed 2025.
• SeriouslyFish. Hemigrammus filamentosus species profile. Accessed 2025.
• Faria, T.C. and F.A.G. Melo (2006). Description of Hemigrammus filamentosus sp. n. from the Rio Araguaia basin, Brazil. Zootaxa, 1286, 55-68.
• Melo, B.F., et al. (2024). Phylogenomics of Characidae. Zoological Journal of the Linnean Society, 202(1), 1-37.

Explore More Tetras

The Phoenix Tetra is just one of dozens of tetra species we cover in our complete species directory. Whether you’re looking for beginner-friendly community tetras or something more specialized, our guide has you covered.

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