The short answer
A 60 litre (about 15 gallon) tank comfortably holds a group of 6 to 8 corydoras of a smaller species. Corydoras are social shoaling fish — they must be kept in groups of 6 or more, never in ones or twos. With their gentle bioload and bottom-dwelling habits, a single-species group of six is the sweet spot for a 60 litre, leaving room for a small shoal of mid-water fish above them.
Why six is the minimum
Corydoras rely on numbers to feel safe. In a group they forage confidently, dash to the surface together for air and rest in contact with each other. Kept alone or as a pair they become withdrawn, stressed and short-lived — hiding instead of behaving naturally. The group isn’t decorative; it’s a basic welfare need. Bigger groups (8–10) look even better and behave more actively.
Sensible 60 litre corydoras stocking
- 6–8 panda corydoras or pygmy corydoras (small, ideal for 60 litres)
- 6 bronze corydoras if you want a slightly larger classic cory
- The cory group plus a mid-water shoal such as ember tetras or harlequin rasboras
Pygmy corydoras are especially suited to smaller tanks and can be kept in groups of 8–10 without straining a 60 litre.
Before you stock
Cycle the tank first — see how to cycle an aquarium. Read the full corydoras care guide, and for larger tanks compare with how many corydoras in a 100 litre tank and how many corydoras to keep together. For the tank, see the best 60 litre aquariums.