Corydoras Minimum Tank Size
The minimum tank size for corydoras is 15 gallons. Here is why, plus group size and the best tankmates.
Quick answer
15 gallons
The minimum tank size for corydoras is 15 gallons. Keep a group of 6 or more of the same species.
The recommended minimum tank size for corydoras is 15 gallons. Corydoras are social bottom dwellers that are far more active and confident in a group. A 15-gallon with a soft sand bed lets a proper group forage naturally. Bigger is always better: a larger tank is more stable and more forgiving, so treat 15 gallons as a floor rather than a target.
Set up a 15-gallon corydoras tank
A 15-gallon (or larger) tank is the right starting size for corydoras.
Most of these species need a stable tropical temperature.
Cycle the tank and keep ammonia and nitrite at zero before adding livestock.
Why corydoras need at least 15 gallons
Corydoras are social bottom dwellers that are far more active and confident in a group. A 15-gallon with a soft sand bed lets a proper group forage naturally. Tank size is not just about the fish fitting in the water; it is about swimming room, water stability, and bioload. A larger volume dilutes waste, holds temperature and chemistry steadier, and gives corydoras room to behave naturally. Cutting below 15 gallons tends to mean more stress, more aggression, and more frequent water problems.
| Detail | Corydoras |
|---|---|
| Minimum tank size | 15 gallons |
| Group / social needs | Keep a group of 6 or more of the same species |
| Recommended starting tank | 15-gallon or larger |
Group size and behavior
Keep a group of 6 or more of the same species. This is a social species that feels secure only in a proper group, so plan the tank around the whole school rather than one or two individuals. A larger group also spreads out activity and reduces stress. For the full picture on diet, water parameters, and breeding, see the full corydoras care guide.
Good tankmates for corydoras
Corydoras generally do well with calm, similarly sized companions. A few reliable options:
- tetras
- guppies
- dwarf gourami
Always confirm that any tankmate shares the same temperature and water-chemistry needs, and that your tank is large enough for everyone combined. Use the stocking calculator to check the full bioload before you add fish.
Plan the tank
Once you have settled on a tank, size the gear with the 15-gallon tank setup guide and confirm the volume with the minimum tank size calculator.
Frequently Asked Questions
What is the minimum tank size for corydoras?
The recommended minimum tank size for corydoras is 15 gallons. Corydoras are social bottom dwellers that are far more active and confident in a group. A 15-gallon with a soft sand bed lets a proper group forage naturally. Treat that as a floor, since a larger tank is more stable and more forgiving.
Can you keep corydoras in a smaller tank?
Going below 15 gallons usually means more stress, more aggression, and faster swings in water quality. The extra volume of the recommended size dilutes waste and steadies temperature and chemistry, which keeps corydoras healthier. Bigger is better whenever you have the space.
How many corydoras should you keep together?
Keep a group of 6 or more of the same species. This is a social species, so plan around the full group rather than one or two, and provide a tank large enough for the whole school.
What are good tankmates for corydoras?
Corydoras do well with calm, similarly sized companions such as tetras, guppies, dwarf gourami. Always confirm shared temperature and water-chemistry needs, and run the full stock list through a stocking calculator so you do not overload the tank.
Planning or running a tank?
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