Corydoras — “corys” — are the friendly, busy little catfish that give a community tank its charm, endlessly foraging along the bottom in social groups. They are hardy, peaceful and genuinely useful, cleaning up leftover food. There’s just one myth to bust: they are not a “cleanup crew” that lives on scraps — they need feeding and company. This UK guide covers corydoras care.

Here’s how to keep them thriving.

Quick facts

• Adult size: 4–7 cm (species-dependent)
• Tank size: 75 litres for a group of 6+
• Water: pH 6.0–7.5, 22–26 °C
• Lifespan: 5–10+ years
• Temperament: peaceful, social

Keep them in groups, on sand

Corydoras are social and must be kept in groups of at least six — a lone cory is a stressed cory. They also do best on soft sand, which lets them sift and forage naturally; sharp gravel wears down and infects their delicate barbels. See substrate guide.

Feeding

Corys need their own food — they won’t thrive on scraps alone. Offer sinking pellets and sinking wafers that reach the bottom, plus occasional frozen bloodworm. Feed after lights-out if faster fish outcompete them. To breed them, see breeding corydoras.

Tank mates

Corys suit almost any peaceful community: tetras, rasboras, livebearers, gouramis and shrimp. Avoid large aggressive fish and anything that harasses bottom dwellers.

Frequently asked questions

How many corydoras should be kept together?

At least six. Corydoras are social fish that become stressed and reclusive when kept alone or in small numbers — bigger groups are happier and more active.

Do corydoras need sand?

Soft sand is best, as it lets them sift and forage naturally without damaging their delicate barbels. Sharp or coarse gravel can wear down and infect their barbels over time.

Do corydoras clean the tank?

They help by eating leftover food, but they are not a cleanup crew that lives on scraps. Corydoras need their own sinking food to stay healthy.

---

— Jaqline Smalling, FishForever