Freshwater Tetra Care Guide: Species, Tank Size & Mates
Freshwater tetra care begins with understanding the species you choose. Tetras are the heartbeat of the freshwater hobby. These small, peaceful, brilliantly colored schooling fish bring movement and life to almost any community aquarium — and most species are hardy enough for beginners while staying interesting enough to keep lifelong hobbyists hooked. From the iconic Neon to the shimmering Cardinal and the fiery Ember, there’s a tetra for every tank.
This complete guide from Tropical Treasures Wyo in Cheyenne, Wyoming covers what makes tetras special, the best species we stock, how to care for them, and the tank mates and setups that let them thrive. Live fish are available for in-store purchase or local pickup only.
What Is a Tetra?
Tetras are freshwater fish commonly kept in a home aquarium; many popular species belong to the family Characidae and originate in South America, while other tetra groups occur in Africa. Small tetras vary greatly in care level, adult size, and preferred water chemistry. Almost all of the tetras in the hobby share a few defining traits:
- Small size — most stay between 1 and 2.5 inches, making them perfect for community tanks.
- Schooling behavior — they feel safest and look their best in groups of six or more.
- Peaceful temperament — the vast majority are gentle community fish (with a few fin-nipping exceptions).
- Vivid color — from neon stripes to translucent bodies, tetras deliver some of the brightest color in freshwater.
If you’re new to schooling fish in general, our guide to the best schooling fish for freshwater aquariums is a great companion to this one.
Best Tetras — Our Top Picks
1. Cardinal Tetra — The Showstopper
The Cardinal Tetra (Paracheirodon axelrodi) is arguably the most beautiful tetra in the hobby — a full-length red stripe beneath an electric-blue line, brighter than the Neon. They prefer warm, soft, slightly acidic water and look spectacular in large schools in a planted tank.
2. Neon Tetra — The Classic
The Neon Tetra is the fish that launched a million aquariums. Hardy, inexpensive, and endlessly popular, neons are perfect schooling fish for beginners. We also stock striking variants like the Black Neon Tetra, the Green Neon Tetra, and the Gold Neon Tetra.
3. Ember Tetra — The Nano Favorite
The Ember Tetra (Hyphessobrycon amandae) is a tiny, glowing-orange nano fish that’s perfect for smaller planted tanks. They school tightly and pop against green plants — a top pick for our nano fish lineup.
4. Rummynose Tetra — The Synchronized Schooler
The Rummynose Tetra (Hemigrammus rhodostomus) sports a bright red nose and a black-and-white striped tail, and schools more tightly than almost any other fish. Their red coloration also doubles as a water-quality indicator — it fades when conditions slip. We also carry the Brilliant Rummynose Tetra.
5. Ember, Lemon & Color Tetras
For a splash of warm color, the Lemon Tetra brings soft yellow, the Bleeding Heart Tetra wears a distinctive red spot, and the Diamond Tetra shimmers with iridescent scales.
6. Pristella (X-Ray) Tetra — The Hardy One
The Pristella Tetra, or X-Ray Tetra, has a translucent body and is one of the toughest, most adaptable tetras — tolerating a wide range of water parameters, which makes it excellent for beginners.
7. GloLight & Unique Tetras
Other standouts we stock include the orange-striped GloLight Tetra, the diagonally-striped Penguin Tetra, the electric-blue Blue Cochu Tetra, and the warm-toned Silvertip Tetra. Browse the full tetras collection to see everything in stock.
Tetra Care Basics
Water Parameters
Many popular tetras originate in waterways with soft, acidic water, though individual species differ. Aim for a temperature of about 72–80°F and a pH of 6.0–7.5 where appropriate for the species. Some blackwater specialists prefer very soft water, but others adjust to moderately hard conditions when kept consistently. Use a suitable test kit to monitor tank water and maintain stable water parameters rather than making sudden changes. Soft water alone is not a reason to alter a thriving aquarium. Wild-type species like Cardinals and Rummynose prefer the softer, more acidic end; hardier, tank-bred species like Pristella and Black Neons tolerate a wider range. The single most important rule: stability beats perfection — steady parameters keep tetras healthier than chasing an exact number.
Schooling and Numbers
Always keep tetras in groups of at least six of the same species — more is better. A lone tetra is a stressed tetra, prone to fading color, hiding, and even fin-nipping. Larger schools spread out aggression, encourage natural behavior, and look dramatically better. A tank must be large enough for the adult fish and their swimming activity rather than simply holding the minimum number.
Tank Size and Setup
The minimum tank size depends on species, group size, and swimming behavior. A 10 gallon planted aquarium can suit some tiny, relatively sedentary species in an appropriate group, but active and larger tetras generally need more space. Most commonly kept tetras thrive in tanks of 10 to 20 gallons and up, depending on species and school size. Keep a zone of open water so a school can swim freely. They show their best color in a planted tank with darker substrate and gentle flow — a setup our best fish for a planted aquarium guide explores in depth. Add some beginner-friendly live plants for cover and the school will feel secure.
Feeding
Tetras are easy to feed and accept high-quality flakes, micro-pellets, and live and frozen foods like baby brine shrimp and daphnia. Choose appropriately sized live foods or prepared alternatives and vary the menu. Small portions of live or frozen food provide enrichment, but avoid excess feeding. A varied diet brings out the best color. Our pellet vs flake guide and how often to feed your fish guide cover the details, and you can shop our fish food flakes for tetra-appropriate options.
Cycling Your Tank First
Tetras — especially sensitive species like Cardinals and Neons — are vulnerable to ammonia, so never add them to an uncycled tank. Read our complete nitrogen cycle guide before stocking.
Tetra Breeding and Life Expectancy
Most small tetra species are egg scatterers rather than livebearers. Some are difficult to breed in a home aquarium because eggs and fry require specific water conditions, careful handling, or protection from adults. Breeding certain wild-type tetras may call for very soft water with a soft, acidic pH, while others breed under less specialized conditions. Check species-specific recommendations instead of changing established water chemistry abruptly.
After hatching, young tetras usually become free swimming within several days, depending on species and temperature. Fry may initially need infusoria or other microscopic food before accepting newly hatched brine shrimp. Adults often eat eggs and fry, so breeders may use fine-leaved plants or a separate spawning tank.
Life expectancy varies by species, genetics, and husbandry, with many common tetras living around three to five years or longer under good conditions. Stable water, an appropriately sized group, and a varied diet support long-term health.
Best Tetra Tank Mates
Many tetras are top to mid-dweller fish, although the exact swimming level depends on the species. Tetras are model community fish. Great companions include:
- Other peaceful tetra species and small rasboras
- Corydoras catfish and other peaceful bottom dwellers
- Dwarf cichlids like Rams and Apistogramma (in larger tanks)
- Peaceful livebearers, small plecos, and freshwater shrimp (with smaller tetra species)
What to avoid: large or aggressive fish that will eat them, and fin-nippers paired with long-finned tankmates. A few tetras (Serpae and Black Skirt) can themselves nip fins if kept in too-small groups — keep them in larger schools to curb it.
Common Tetra Mistakes
- Buying too few. Schools under six lead to stress, faded color, and nipping.
- Adding them to a new tank. Uncycled water and ammonia spikes are the #1 killer of new tetras.
- Mismatched water. Soft-water species like Cardinals struggle in hard, alkaline water long-term.
- Aggressive tank mates. Anything big enough to fit a tetra in its mouth eventually will.
- Skipping acclimation. Tetras are sensitive to sudden parameter changes — acclimate slowly.
Frequently Asked Questions
How many tetras should I keep together?
At least six of the same species, and ideally more. Tetras are schooling fish that feel safe in numbers — larger groups show better color, more natural behavior, and less aggression.
Are tetras good for beginners?
Yes. Hardy species like Pristella (X-Ray), Black Neon, and standard Neon Tetras are among the best beginner fish, as long as you cycle the tank first and keep them in a proper school.
What’s the difference between Neon and Cardinal Tetras?
Both have a blue stripe, but the Cardinal’s red stripe runs the full length of its body, while the Neon’s red covers only the rear half. Cardinals are larger and a bit more demanding about soft, warm water.
How big do tetras get?
Most tetras stay between 1 and 2.5 inches. Nano species like the Ember Tetra stay under an inch, while larger tetras like the Bleeding Heart can approach 2.5–3 inches.
What water temperature do tetras need?
Most tetras do best between 72–80°F. Discus-style warm-water tetras like Cardinals appreciate the higher end of that range.
Can tetras live with shrimp?
Smaller, peaceful tetras can coexist with adult freshwater shrimp, especially in a planted tank with cover, though baby shrimp may be eaten. Larger tetras are riskier shrimp companions.
Why are my tetras losing their color?
Faded color usually signals stress — from poor water quality, too small a school, an uncycled tank, or aggressive tank mates. Check your parameters and school size first. Persistent issues may point to illness; see our common fish diseases guide.
Build Your Tetra Tank
Ready to add a shimmering school to your aquarium? Browse our most relevant collections:
Have questions about which tetras are right for your setup? Contact Tropical Treasures Wyo at 307-369-1118 or visit our shop at 190 S College Drive, Suite D, Cheyenne, WY 82007. Live fish are available for in-store purchase or local pickup only.
Related guides: Best Schooling Fish · Best Fish for a Planted Aquarium · Best Nano Fish · The Nitrogen Cycle · Pellet vs Flake · Common Fish Diseases