Quick answer: Keep neon tetras in a tank at least 60 cm long. Use a group of 5 or more fish. Feed a small daily diet they can finish in a few minutes.
Neon tetras stay under 2.5 cm SL and need a 60 cm tank in groups of 5 or more.
This page is a published-spec briefing for home tanks. We did not keep a neon tetra school, run water trials, or breed the species.
Our research team analyzed FishBase species records and maker food labels. We did not invent a captive lifespan, because FishBase does not publish one.
FishBase names this fish Paracheirodon innesi, and adults eat worms, small insects, crustaceans, and plant matter.
What this desk covered, and what it left out
We used one rule for every tank, school, and food that made this page, and we call it the Length-and-Label Rule.
A setup is in scope only if it can meet FishBase’s 60 cm tank length and a group of 5 or more fish.
A food is in scope only if the maker page names tetras or small-mouthed tropical fish, or lists a flake or micro-granule form.
We left out these cases:
- Bowls and tanks shorter than 60 cm
- Single fish, pairs, and trios
- Breeding racks and outdoor ponds
- Goldfish formulas, wafers, sticks, and color-only treats
- Cardinal tetra records and wild-collection advice
In September 2026, the Waterpuppy Spec Desk compared five currently sold daily diets. We read each maker’s own page and did not rank the foods.
Tank size: measure length, not the gallon label
FishBase lists a minimum aquarium size of 60 cm for neon tetras, and that number is length, not volume.
Sixty centimeters is about 24 inches, and if the glass is shorter than that, the tank fails the published rule.
Do not convert gallons in your head and stop there, because two boxes can share a gallon label and still have different swim lengths.
Check the tank this way:
- Measure the inside length of the glass.
- Confirm it is at least 60 cm, or about 24 inches.
- Leave a clear midwater lane so the school can travel in a line.
- Recheck length if a large hardscape cuts that lane.
A short, tall box can hold many gallons and still fail. FishBase’s rule is a footprint rule, not a gallon rule.
We did not set a liter or gallon floor of our own. Volume still matters for filter load and heat, but length is the published starting point.
School size: five is the published floor
FishBase says to keep neon tetras in groups of 5 or more individuals, and that is a count, not a mood.
Five is the floor we use on this page, and it is not a display target. A larger group still has to fit the 60 cm length.
Use this stocking check:
- Start at 5 fish, which is the FishBase floor.
- Add fish only if the tank still meets 60 cm of open length.
- Do not add a lone neon tetra to fill empty water.
- Do not mix in one extra tetra from another species and call it a school.
A school is the same species moving together, and one neon tetra is not a school.
If you want a smaller tetra often sold for shorter tanks, read our ember tetra care page. That brief does not change the 60 cm rule for neon tetras.
Water values from the species record
FishBase publishes a narrow water band for this species, and we did not widen it.
Here are the numbers on that record:
- pH range: 5.0 to 7.0
- dH range: 1 to 2
- Temperature: 20°C to 26°C (68°F to 79°F)
- Habitat note: blackwater or clearwater stream tributaries of the Solimões River
Those hardness numbers are very soft, and many home taps run harder. We did not write a wider “safe” band, because we did not find one on FishBase.
If your tap sits outside that band, treat it as a mismatch and do not rewrite the record to match the tap.
FishBase also lists a tropical climate band and a pelagic freshwater life. Neon tetras use the water column, not the glass floor.
We did not pull a flow rate, a light wattage, or a plant list from FishBase. Those items are not on the species summary we used.
Diet: match the mouth, then read the label
FishBase says adults feed on worms, small insects, crustaceans, and plant matter. That is an omnivore pattern, not a flake-only rule.
The published max length is 2.5 cm SL. SL means the body without the tail fin, so food has to fit that mouth.
The Waterpuppy Spec Desk compared five daily diets still sold in September 2026. We used maker pages only and did not time feedings in a tank.
| Product | Form on maker page | Crude protein | Crude fat | Other listed attribute |
|---|---|---|---|---|
| Fluval Bug Bites Tropical Micro Granules | Slow-sinking micro granules, 0.25–1.4 mm | 40.0% minimum | 12.5% minimum | Up to 40% black soldier fly larvae |
| Hikari Micro Pellets | Semi-floating, slowly sinking pellets | 43.0% minimum | 7.0% minimum | Vitamin A minimum 16,000 IU/kg |
| TetraMin Flakes | Flake mix that floats, then sinks | 46% | 11% | Vitamin D3 1,848 IU/kg |
| Omega One Freshwater Flakes | Freshwater flake | 39% minimum | 11% minimum | Maximum ash 8% |
| API TROPICAL FLAKES | Flake for tropical community fish, including tetras | Not listed on maker page | Not listed on maker page | Up to 30% less ammonia; feed twice a day in 3 minutes |
Four of those pages list protein, and the spread is 39% to 46%. The same four pages list fat, and that spread is 7.0% to 12.5%.
Moisture on the same labels also differs:
- TetraMin Flakes: 7% moisture
- Omega One Freshwater Flakes: 8.5% maximum moisture
- Hikari Micro Pellets: 10.0% maximum moisture
- Fluval Bug Bites Tropical Micro Granules: 10.0% maximum moisture
Hikari Sales USA lists Vitamin A at a minimum of 16,000 IU/kg on Micro Pellets. Fluval’s page for Bug Bites Tropical Micro Granules lists Vitamin A at a minimum of 2,500 IU/kg.
That 13,500 IU/kg spread is a label gap, not a feeding trial.
Tetra’s page for TetraMin Flakes lists Vitamin D3 at 1,848 IU/kg. Hikari’s Micro Pellets page lists Vitamin D3 at a minimum of 2,400 IU/kg.
Fluval’s page also lists calcium at 1.50% minimum and phosphorus at 0.80% minimum. Hikari’s page lists phosphorus at 1.1% minimum and ascorbic acid at 360 mg/kg.
Fluval’s granule range is 0.25–1.4 mm, which sits far below a 2.5 cm SL body, and large wafers do not.
Hikari Sales USA describes Micro Pellets as a daily diet for smaller-mouth fishes. Pack sizes on that page are 0.77 oz, 1.58 oz, and 2.2 lb.
OmegaSea’s page for Omega One Freshwater Flakes lists salmon and whole herring first. It also lists a maximum ash of 8%.
Omega One pack sizes on that page run from 0.42 oz to 5 lb. Tetra lists TetraMin Flakes in these packs:
- 100 ml / 20 g
- 250 ml / 52 g
- 500 ml / 100 g
- 1 L / 200 g
- 10 L / 2.1 kg
API Fishcare’s page names tetras on API TROPICAL FLAKES. Use the maker’s own feed window:
- Feed twice a day.
- Offer only what the fish finish in 3 minutes.
If flakes are large, pinch them smaller before they hit the water, and do not leave a film on the surface.
Rotate forms if the fish ignore one texture, because the table is a label map and not a scoreboard.
Lifespan: FishBase does not publish a year count
FishBase does not list a captive lifespan for Paracheirodon innesi, and we will not invent one.
What the same record does publish is shorter-cycle data:
- Eggs in a tank hatch in about 24 hours.
- Resilience is listed as high, with a minimum population doubling time of less than 15 months.
- Fishing vulnerability is listed as 10 of 100, in the low band (0 to 25).
- Trophic level is listed as 2.9, plus or minus 0.32, based on food items.
Those figures describe population pace and diet position, and they do not tell you how many years a home fish will live.
FishBase reports the IUCN Red List status as Least Concern. The assessment date on that record is 4 March 2021.
CITES is listed as Not Evaluated on the same FishBase record. We did not treat Least Concern as a care grade, because it is a wild-status tag and not a tank warranty.
If a seller promises a fixed year span, ask where that number was published. It is not on the FishBase summary we used.
Stable length, a real school, and a food the fish can finish are the levers this page can support. A year count is not one of them.
FAQ
How big do neon tetras get?
FishBase lists a maximum length of 2.5 cm SL. SL is standard length, which leaves out the tail fin. That is a small fish with a small mouth, so large pellets and whole wafers are a poor match.
What tank size do neon tetras need?
FishBase lists a minimum aquarium size of 60 cm. Measure length, not the gallon sticker. If the glass is under about 24 inches, it fails that rule.
How many neon tetras should I keep?
FishBase says groups of 5 or more. Do not keep one, two, or three as a starter set. Add more only if the tank still meets the 60 cm length.
What water temperature do neon tetras need?
FishBase lists 20°C to 26°C, which converts to 68°F to 79°F, so stay inside that band. We did not add a tighter sweet spot of our own.
What should I feed neon tetras?
FishBase lists worms, small insects, crustaceans, and plant matter. On the dry side, use a flake or a micro granule the fish can swallow. API Fishcare’s page for API TROPICAL FLAKES says to feed twice a day, only what they finish in 3 minutes.
How long do neon tetras live?
FishBase does not publish a captive lifespan, and we will not fill that gap with a guess. Plan for ongoing care, not a promised number of years.
Can I keep neon tetras with ember tetras?
This page did not build a tank-mate matrix. Ember tetras are a different small tetra with their own brief on our ember tetra care page. Any mix still has to meet the 60 cm length and a neon school of 5 or more.
