Flame Tetra: A Complete Care, Tank, and Breeding Profile

A 1924 description by Myers introduced the species now prized for its fiery red-orange flanks and gentle schooling behavior in planted community tanks. Adults reach roughly 2.5 to 4 cm, so a school of six fits comfortably in a 60-liter aquarium with soft, slightly acidic water held between 22 and 28 degrees Celsius. Wild populations come from coastal rivers near Rio de Janeiro in southeastern Brazil, where tannins and leaf litter push pH down and keep general hardness low. Today, most its sold in pet stores are tank-bred, which makes them adaptable to a wider range of parameters than their wild ancestors.

This Flame Tetra care guide covers identification, tank size, water chemistry, feeding, compatible tankmates, breeding protocol, and long-term health watchpoints so you can build a thriving school without the usual beginner pitfalls.

What a Flame Tetra Is and Where It Comes From

Specimens collected near Rio de Janeiro in 1924 led Myers to describe Hyphessobrycon flammeus, a species that aquarists soon nicknamed the Red Tetra or Von Rio Tetra. In the wild it lives in slow, tannin-stained tributaries where overhanging vegetation keeps light low and the water carries a gentle amber tint. Those quiet, shaded conditions shape nearly every preference the fish shows in captivity, from its comfort in dim lighting to its need for soft, slightly acidic water.

Because the species is so widely bred, adults in pet stores often look more vivid than their wild cousins, and that bright red body is exactly what draws beginners in. Coloration intensity rises with age, social comfort, and clean water, so a pale fish in a bare tank is usually a stressed fish, not a sick one.

How to Tell It Apart From Look-Alikes

Pet stores routinely mislabel this species as the Serpae Tetra (Hyphessobrycon eques) or the Red Phantom Tetra (Hyphessobrycon sweglesi), and the mix-up costs hobbyists their peaceful community plans. The Flame Tetra has a stockier body than the slim, tall Serpae, and it lacks the Serpae’s bold black comma behind the gill plate. The Red Phantom shows a rounded black shoulder patch surrounded by a bright red ring, while the it shows two short, dark vertical bars just behind the gills and a more uniform red-orange body with darker fins.

“Rule of thumb: two thin dark bars behind the gills and a fiery, all-over red body point to a true Flame Tetra; a single rounded shoulder patch points to a Red Phantom; a tall body with a large black shoulder blotch points to a Serpae.

Behavior helps confirm the ID. Flame Tetras stay calm when kept in a proper school, while Serpaes are notorious fin-nippers that will shred the tails of slow-moving tankmates no matter how large the group. If a fish in the store is harassing its neighbors, it is almost certainly not a it.

Size, Shape, and Color Signals

Adult its top out near 4 cm, with most individuals settling between 2.5 and 3.5 cm. Females stay plumper and slightly shorter than males, while males develop a more elongated dorsal fin and a deeper red wash across the body. Both sexes darken during spawning readiness, with males flashing the most intense color as they display for a female.

Color is your fastest health check. A pale, washed-out fish in a clean, planted tank with stable parameters is usually being bullied, kept in too small a group, or held in water that is too hard and alkaline for its liking. Recovery is often as simple as fixing the social or chemical environment rather than reaching for medication.

Setting Up the Right Tank for a School of Flame Tetras

A 60-liter (about 15-gallon) long-footprint tank is the practical minimum for a it school of six, and longer is always better than taller for a fish that cruises the mid-column. A 60 cm (24-inch) length gives the school room to spread out and reduces the territorial pressure that triggers nipping in cramped quarters. Going up to a 75- or 95-liter tank lets you keep 10 to 12 fish, which produces a much more natural, tightly-grouped display.

Group Size, Layout, and Filtration

Six is the non-negotiable floor, and here is why: in groups of three or four, the dominant male focuses its energy on the few tankmates it has, and the stress shows up as torn fins and faded color. In groups of eight or more, that same energy spreads out, the school behaves as one unit, and fin-nipping incidents drop to almost zero. If a community tank already houses a long-finned fish like a guppy or betta, leaning toward the higher end of the school size is the cheapest insurance you can buy.

For decor, lean into a planted layout with a dark, fine-grained substrate, dim lighting (either a low-wattage fixture or floating plants like Amazon frogbit), and a clear mid-column lane for the school to patrol. Driftwood and Indian almond leaves help recreate the tannin-stained character of the native habitat and gently soften the water at the same time. Filtration should turn the tank volume over four to six times per hour with a gentle outflow; sponge filters and canister filters with a spray bar both work well, and strong jet outputs tend to push this calm species into the corners.

Scaling the School to a Bigger Tank

Use roughly 10 liters per additional fish when scaling up, with the same long-footprint preference. A 95-liter tank holds a school of 10 comfortably, and a 130-liter setup can support 12 with room for a small group of bottom-dwellers like corydoras. The school should still be introduced all at once rather than added in stages, since mixing strangers into an established group can briefly reset the pecking order.

Once the school structure feels settled, the real test is whether the water itself matches what those new group dynamics actually demand.

Water Parameters That Match the Flame Tetra’s Needs

Soft, slightly acidic water mirrors the species’ native blackwater-influenced rivers, and getting this right will pay off in brighter color, tighter schooling, and longer it lifespan. Aim for pH 5.5 to 7.0, general hardness (GH) of 2 to 8 dGH, and a stable it temperature between 22 and 28 degrees Celsius (72 to 82 degrees Fahrenheit). Hardness matters more than pH in practice, because a stable pH of 7.2 in soft water is far less stressful than a fluctuating pH of 6.5 in hard, mineral-rich water.

Reading Test Results and Adjusting Tap Water

Run a liquid test kit like the API Freshwater Master Test Kit on fresh tap water before you set the tank up, then again weekly for the first month. If your tap comes out above 8 dGH or above pH 7.2, you have two practical paths: blend tap with reverse-osmosis (RO) water to bring hardness down, or add natural softeners directly to the tank. Peat pellets in the filter, a couple of Indian almond leaves per 40 liters, and alder cones will all gradually lower pH and tint the water a light tea color, which doubles as a stress-reducer for the fish.

Parameter	Target Range	What Happens Outside the Range
Temperature	22 to 28 degrees C (72 to 82 degrees F)	Below 22 triggers ich susceptibility; swings cause color loss
pH	5.5 to 7.0	Above 7.5 dulls color and shortens lifespan
General Hardness (GH)	2 to 8 dGH	Above 12 dGH stresses kidneys and lowers breeding response
Carbonate Hardness (KH)	1 to 4 dKH	Higher KH locks pH in place and prevents tannin-driven softening
Nitrate	Below 20 ppm	Levels above 40 ppm suppress color and appetite

Stability matters more than any single number. Two degrees of overnight temperature swing stresses these fish far more than a stable 26-degree reading slightly above or below your original target, so a reliable heater and a lid that holds in heat are worth their cost within a week.

Feeding, Health, and Long-Term Watchpoints

its are eager omnivores that thrive on a base of quality flakes or micro-pellets sized for small mouths, supplemented two to three times a week with frozen foods. A varied rotation of frozen daphnia, baby brine shrimp, and bloodworms keeps color vivid and supports breeding condition. Feed only what the school can finish in two to three minutes; overfeeding is the most common cause of the nitrate creep and fin-rot flare-ups that beginners blame on the fish itself.

Daily Health Indicators You Can Read in Seconds

Three signals tell you almost everything about a it’s condition before you ever need a test kit. Color is the first: a faded fish in a stable tank is either sick, bullied, or in water that is too hard. Appetite is the second: a it that ignores food is usually stressed or newly introduced, and a school-wide feeding strike usually points to a water-quality event. Schooling tightness is the third: loose, scattered fish suggest a stressor, while a tight, coordinated group that moves as one unit is the visual gold standard of a healthy setup.

Watchpoints Over a 3 to 5 Year Lifespan

A well-kept it typically lives 3 to 5 years, with some individuals reaching 6 in mature, stable planted tanks. Ich is the most common disease, and it almost always shows up after a temperature dip or an overnight heater failure rather than from a new fish. Quarantine new arrivals for two weeks, run a UV sterilizer if your water runs warm, and keep a spare heater on hand for the one cold night that decides everything.

“Watchpoint: stress-induced color fading is a chemistry or social problem long before it is a disease problem, and the fix is almost always a water change, a larger school, or a softer parameter, not a medication.

By the third year, older males start to lose a little of their red intensity, and females may look slightly plumper than they did at year one. Both changes are normal aging, not illness, and they tell you the long-term setup is working.

Healthy, well-fed tetras are easier to pair with neighbors, so the watchpoints above shape every stocking decision that follows.

Compatible Tank Mates for a Peaceful Community

A properly schooled it is one of the calmer tetras in the hobby, and that temperament makes it a strong match for other small, peaceful schooling species. The single biggest factor in compatibility is the school’s own size: a tight group of 8 to 12 its will ignore tankmates it would otherwise pick at, while a lonely group of 3 will go after anything that swims slowly past.

When people ask are its aggressive, the answer is almost always tied back to group size, not species temperament, which is why the social setup matters more than the tankmate list itself.

Recommended Flame Tetra Tankmates

• ▸Neon and Cardinal Tetras: share the same soft, acidic water and form a calm, parallel school in the mid-column.
• ▸Harlequin and Lambchop Rasboras: peaceful mid-column swimmers that mirror schooling behavior without competing for the same micro-zones.
• ▸Corydoras Catfish: occupy the bottom layer, sift the substrate, and balance the tank’s workload.
• ▸Otocinclus: small algae grazers that stay out of the way of the tetra school entirely.
• ▸Pygmy Corydoras: a charming size contrast in a 60- to 95-liter setup, turning the lower third into its own quiet scene.
• ▸Peaceful Dwarf Gouramis: work when the individual chosen is calm, not one of the more territorial males.

Tank Mates to Avoid

Skip any fish with long, flowing fins or a slow, deliberate swimming style. Bettas, fancy guppies, angelfish, gouramis with threadfin extensions, and most livebearers with showy tails will eventually get nipped, even by an otherwise calm it school. The other hard rule is size: any fish large enough to swallow an adult it will eventually try to, so avoid medium to large cichlids, large gouramis, and most semi-aggressive barbs. Shrimp and snails are usually safe, though very small shrimp fry may be picked off by the school.

Tank Mate Type	Compatibility	Notes
Neon and Cardinal Tetras	Excellent	Same water needs, peaceful schoolers
Harlequin Rasboras	Excellent	Calm mid-column swimmers, match the schooling behavior
Corydoras Catfish	Excellent	Bottom layer keeps the tank balanced
Otocinclus	Excellent	Algae grazers that stay out of the way
Dwarf Gourami	Good	Choose a peaceful individual, not an aggressive one
Betta (especially long-finned)	Poor	Slow fins invite nipping; fights often follow
Angelfish	Poor	Large enough to swallow adults; also a fin-nipper
Cherry Shrimp Adults	Good	Adults are usually ignored; very small fry may be eaten

Breeding Flame Tetras at Home: A Practical Protocol

its are egg-scattering breeders that show no parental care, and a successful spawn is mostly a matter of preparation, timing, and protecting the eggs from their own parents. With a stable pair or a small group in a dedicated breeding tank, expect realistic survival rates of 30 to 60 percent from egg to free-swimming juvenile under a careful routine. A first attempt is rarely a numbers win, so set the goal as a healthy batch of fry rather than a target headcount.

Sexing and Conditioning the Pair

Males glow brighter red as they mature, and their dorsal fin elongates into a slight hook, while females stay plumper, slightly shorter, and a touch duller in body color. Pick a male with the deepest red wash and a female with a clearly rounded belly viewed from above. Condition both fish for 7 to 10 days on a high-protein diet of live or frozen baby brine shrimp, daphnia, and finely chopped bloodworms, with smaller amounts of quality flakes between protein feedings.

Setting Up the Breeding Tank

A 20- to 40-liter tank works well for a single pair, and the setup should be dim, simple, and protected. Fill it with soft, acidic water matching pH 5.5 to 6.5 and GH 1 to 4, ideally mixed from RO and tap so the parameters actually trigger spawning. Add a spawning mop, a clump of fine-leaved plants like java moss, or a layer of marble-sized pebbles on the bottom, since any of these will catch the scattered eggs and keep them out of the parents’ reach. A sheet of mesh placed an inch above the floor also works, because eggs fall through the gaps while adults cannot follow.

“Tip: keep the breeding tank in a low-traffic area with no direct overhead light. its often refuse to spawn under bright conditions, and a sudden flash from a doorway is enough to spook a pair that was seconds away from releasing eggs.

Spawning, Egg Care, and Fry Rearing

Introduce the conditioned pair in the evening, and expect courtship and spawning to begin the following morning. The male displays by flaring his fins and swimming in a tight pattern around the female, who releases a small batch of eggs that the pair scatter across the plants, mop, or mesh. Remove both parents immediately after spawning, either by netting them out or by siphoning the eggs into a clean, parameter-matched container, because adults will hunt the eggs within hours.

Eggs hatch in 24 to 36 hours, and the fry hang on plant leaves and glass for another 2 to 4 days while they absorb their yolk sacs. Start feeding with infusoria or a commercial liquid fry food for the first week, then move to freshly hatched baby brine shrimp once the fry are free-swimming and visibly hunting. Daily 10-percent water changes with matched parameters keep the rearing tank clean without shocking the fry, and the first month is the period where most losses happen. By the end of week 4 the juveniles are usually large enough to accept finely crushed flakes, and by month 3 they show the beginnings of adult coloration.

With juveniles on their way to adult color, the broader picture of what makes a flame tetra thrive finally clicks into focus.

Bringing It All Together

The it rewards the basics more than any rare supplement or fancy piece of equipment. A long tank, a school of at least six, soft acidic water, a varied diet, and calm tankmates will produce a vibrant, long-lived display that gets more impressive with every month of stable care. Get the social and chemical environment right, and breeding almost takes care of itself, which is the clearest sign that your setup matches what the species actually needs.

FAQ