TankStockingHow many Bronze Corydoras in a 20 gallon tank?
A 20-gallon (76 L) tank comfortably holds about 6–8 Bronze Corydoras as a single-species display — a conservative range that leaves room for tankmates and a margin for error.
Bronze Corydoras key facts
| Adult size | 7 cm |
|---|---|
| Minimum tank | 20 US gal |
| Minimum group | 6+ (shoal) |
| Temperament | Peaceful |
| Temperature range | 22–26°C |
| pH range | 6–7.8 |
| Bioload | Medium |
| Swim level | Bottom |
| Beginner-friendly | Yes |
Sources & confidence (1 species)
This backs the Bronze Corydoras size, tank and group figures used here. Each figure is read from the TankStocking species database (v2026.06); below is the care reference behind it and how confident we are in that data. Confidence reflects the source quality, not whether any pairing is safe. Full source list and the welfare model are on the methodology page.
- Bronze Corydoras Corydoras aeneus — Seriously Fish (seriouslyfish.com/species/corydoras-aeneus) high confidence
TankStocking sizes this from a per-species footprint — the territory and waste a single Bronze Corydoras needs in a comfortable display tank — rather than the unreliable "inch per gallon" rule. On that basis a 20-gallon tank comfortably suits about 6–8 Bronze Corydoras. Keep a minimum of 6 — Bronze Corydoras is a social species that suffers in smaller groups. This is a comfortable display range, not a hard ceiling: stocking lighter keeps water quality stable and leaves headroom for tankmates and growth.
TankStocking's bio-load gauge alone would not flag a tank this size as over-stocked until roughly 11 Bronze Corydoras — but that is a model maximum, not the recommended number. It leaves no headroom for water-quality swings, tankmates, or growth, so treat 6–8 as the comfortable target.
They occupy the floor, ask nothing of mid-water fish, and clear the engine against almost every peaceful community species. The few cautions are temperature edges and very large or aggressive tankmates. Keep them in a group of six or more on smooth sand or rounded gravel that protects their barbels.
Want a community rather than a single-species tank? The Bronze Corydoras tank mates guide lists the species the engine clears with Bronze Corydoras.
8× Bronze Corydoras
✓ Good starter plan8× Bronze Corydoras
About 6–8 Bronze Corydoras is a comfortable display level for 20 gallons — fewer is always safer, and leaves headroom for tankmates.
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Verdict
Common questions
How many Bronze Corydoras can I keep in a 20-gallon tank?
A 20-gallon (76 L) tank comfortably holds about 6–8 Bronze Corydoras as a single-species display — a conservative range that leaves room for tankmates and a margin for error.
What size tank do Bronze Corydoras need?
Bronze Corydoras need at least 20 US gallons, kept in a group of 6 or more. Bigger is better — more water means more stable parameters and more room to stock tankmates.
More on stocking Bronze Corydoras
Related guides on TankStocking — each scored by the same welfare engine as the planner.
Bronze Corydoras tankmates & community
Bronze Corydoras in other tank sizes
Stocking numbers are planning estimates — filtration, planting, and maintenance all shift the real ceiling. Cycle the tank and stock gradually. How this estimate works →