Neon Tetra Tank Mates: Safe Picks and Fish to Avoid
Published: 2026-11-05 · FishyKart Blog
The best neon tetra tank mates are fish that are small, calm and happy in the same soft, slightly acidic water at about 70-77°F (21-25°C). A neon reaches only about 1.2 inches (3 cm), so the main danger in a community tank is not aggression but size: any fish with a mouth big enough will eventually treat a neon as food. Below are the companions that work, the ones that fail, and how to stock a 10 or 20 gallon tank.
Photo: Wojciech J. Płuciennik - Wikimedia Commons, CC BY-SA 4.0
The Rule of Mouth Size
SeriouslyFish calls neons generally peaceful and recommends keeping them with "similarly-sized characids, gasteropelecids, lebiasinids, smaller callichthyid or loricariid catfishes and non-predatory, small-to-medium-sized cichlids". Put simply: other small tetras, hatchetfish, pencilfish, small catfish and dwarf cichlids. A quick test for any fish you are unsure about: if its adult mouth could fit a 1.2 inch fish, skip it.
12 Good Tank Mates for Neon Tetras
| Fish | Level | Note |
|---|---|---|
| Ember tetra | Mid | Same size, adds orange |
| Cardinal tetra | Mid | Likes it warmer; keep near 75-77°F (compare) |
| Rummy nose tetra | Mid | Tight schooler for 20+ gallons |
| Harlequin rasbora | Mid | Calm and hardy |
| Chili rasbora | Mid | Tiny; good for 10 gallons |
| Corydoras (pygmy, panda) | Bottom | Keep in groups of 6 |
| Otocinclus | Glass, plants | Only in a mature tank |
| Kuhli loach | Bottom | Shy, needs sand |
| Honey gourami | Top | Calm centerpiece |
| Bristlenose pleco | Bottom | 20+ gallons, needs wood |
| Cherry shrimp | Bottom | Adults safe; shrimplets need moss |
| Nerite snail | Glass | Algae control, no risk |
Dwarf cichlids such as apistogramma and rams also fit SeriouslyFish's "non-predatory small cichlid" group, but they need more experience with water quality, and rams prefer warmer water than neons.
Tank Mates to Avoid
- Angelfish: the classic mistake. Young angels and neons look fine together, but a grown angelfish can eat a neon.
- Medium and large cichlids: oscars, jewel cichlids, African cichlids (which also need hard water).
- Goldfish: coldwater fish that grow large; a different tank entirely.
- Nippy, fast fish: tiger barbs and serpae tetras stress a neon school.
- Discus: need 82-86°F, well above the neon range.
A betta sits in the middle. Many ignore neons in a planted 10 gallon or larger, some chase them, and the betta wants warmer water. Try it only with a spare tank ready.
How Many Neons, and in What Tank
SeriouslyFish recommends a group of at least 8-10 neons and a tank base of about 24 x 12 inches (60 x 30 cm, roughly 15 gallons). That gives simple stocking rules:
- 10 gallon: 6-8 neons as the only school, plus shrimp or a few otos. A 10 gallon is below SeriouslyFish's suggested size, so keep the stocking light.
- 20 gallon long: 10-12 neons, 6 pygmy corydoras, 6 otos or a honey gourami.
- 29 gallons and up: two schools (neons plus rummy nose or harlequins), a corydoras group and a bristlenose pleco.
For more stocking ideas see best fish for a 10 gallon tank and best fish for a 20 gallon tank.
Water: The Hidden Compatibility Test
SeriouslyFish gives neons 70-77°F (21-25°C), pH 4.0-7.5 and 1-12 dGH. Tank mates should overlap that range. Livebearers such as mollies prefer harder, more alkaline water, which is why they are usually listed for different tanks (see molly fish tank mates). Neons also catch the slow-moving neon tetra disease; quarantine every new fish before it joins the school, and read neon tetra disease for the signs.
Sources: SeriouslyFish species profile for Paracheirodon innesi (size, tank base, temperature, pH, hardness, tank mates, group size).
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