When people picture aquaponics, tilapia is usually the fish that comes to mind first, but it’s far from the only choice. Almost any fish can technically be raised this way — what really matters is how much attention a species needs and whether your goal is an ornamental display or a food crop. Tetra fish aren’t the easiest species to start an aquaponics system with, but they come with real advantages once you understand what they require. Here’s what you need to know before setting up a tetra fish aquaponics tank.

Tetra Fish Species

Before picking tetras for your system, it helps to know that there are roughly 150 recognized species. Only a handful are commonly used in aquaponics setups, and each has its own look and needs.

Neon Tetras

This is the tetra most people picture by default. Neon tetras are low-maintenance, thrive in freshwater, and are very calm tankmates. They typically show blue, red, and translucent coloring, and they do best kept in a group of at least 15.

Cardinal Tetras

Cardinal tetras look a lot like neons but with one key difference: the bright red stripe runs the full length of their body, whereas on a neon tetra it only covers the back half, from the midpoint to the tail.

Serpae Tetras

These have a vivid flame-orange color and like to swim together as a group, which makes them stand out nicely in the middle of a tank. They’re generally calm, though somewhat feistier than most other tetra varieties.

Diamond Tetra

Diamond tetras tend to stay near the bottom of the tank and need generous plant cover to feel secure. They can reach about 2.4 inches in length and do best in a group of 6 to 8, which helps curb any fin-nipping tendencies.

Glowlight Tetra

Nearly see-through with a red-orange stripe along its side, the glowlight tetra also prefers groups of 6 to 8. Like most tetras, it favors dimmer tanks with plenty of plants to retreat into.

Optimal Tetra Fish Temperature

Because tetras are native to the Amazon basin, they’re adapted to warm conditions. Keep your tank between 70°F and 81°F, with pH held between 6 and 7 and the water on the soft side. Tetras aren’t especially tough fish — sudden shifts outside these parameters, or changes that happen too fast, can kill them. Even lighting matters: dim, subdued light suits them best. Overall, tetras make a rewarding aquaponics fish, but they’re not a great pick if you’re just starting out.

Tetra Fish Growth Rate

Tetras grow faster than you might expect. Within the first three months, they’ll reach roughly half of their adult size, then take another three months or so to finish growing — a notably quick timeline.

Can You Combine Tetra Fish With Other Fish?

Tetras can technically share a tank with other species — but only if you don’t mind those species eating them. Because tetras are small and non-aggressive, any larger or more aggressive fish sharing their tank is likely to hunt them down. Pairing them with other small, peaceful fish can work, though keeping a dedicated tetra-only aquaponics tank is generally the safer approach.

FAQ about Tetra fish

What do tetra fish eat?

In their natural habitat, tetras eat a mix of small insects, larvae, algae, and other bits of plant matter. In an aquaponics tank, a quality pelleted food covers their nutritional needs. Juveniles should be fed twice daily with small enough pellets to avoid choking hazards, while adults can eat once a day. Adding occasional treats like small bloodworms or brine shrimp helps round out their diet.

How big do tetra fish get?

Plan on roughly 1 to 2 gallons of water per fish, and aim for a group of at least 15 for their wellbeing. Schooling together keeps them calmer and helps them grow more evenly — adults average around 1.5 inches long. It’s best to raise young tetras in a separate tank until they’re about 3 months old, by which point they’re nearly full-grown and won’t be picked on by the adults.

How long do tetra fish live?

Without predators, captive tetras live considerably longer than wild ones — typically around 5 years, with some reaching as old as 8. They’re highly social fish and do best in the company of other tetras.

Where to buy tetra fish?

You can find tetras at local fish shops, aquaponics suppliers, or general pet stores. They’re widely available, inexpensive, and an easy way to add color to your system. If you’re building a dedicated tetra aquaponics setup, buying them young is a good idea — it lets them grow alongside your system for the best long-term results.

What Is Neon Tetra Disease?

Despite the name, this disease can affect a range of fish species, though it was first identified in neon tetras. It attacks fish internally, and infected fish typically lose their color, swim erratically or stay near the bottom of the tank, and lose body condition rapidly. There’s currently no known cure. Because of that, prevention is critical — if any tetra in your system shows symptoms, the safest course is to remove and humanely cull the entire affected group to stop it spreading.