Plan my tank
Fish guides / Corydoras catfish
Bottom dwellers

Corydoras Catfish: Tank Size, Tank Mates and Setup

A peaceful bottom-dwelling catfish for community tanks. Keep six or more of the same species in 20 gallons or larger.

Minimum tank
20 gallons
Temperature
72–79°F
Group size
6 or more
Adult size
2.5 inBottom of the tank
  • Sand or smooth gravel protects the barbels it uses to find food.
  • Needs its own sinking food; it can't live on leftovers.

Corydoras aeneus and similar. Figures are commonly published care ranges; see how it works.

How many corydoras per tank size

The most you could keep if corydoras were the only species. Open a size in the builder to add tank mates.

TankCorydoras catfish, kept alone
5 gallonToo small (needs 20+ gal)
10 gallonToo small (needs 20+ gal)
20 gallonUp to 12Plan this tank
29 gallonUp to 20Plan this tank
40 gallonUp to 27Plan this tank
55 gallonUp to 38Plan this tank
75 gallonUp to 51Plan this tank

What you need for corydoras in a 20-gallon tank

A starting setup: 6 corydoras in the smallest standard tank that suits them.

Your blueprint

20-gallon tank

6 corydoras
Stocking level43% · Good
  • These fit a 20-gallon tank and get along. Aim for about 76°F.

Equipment, sized for this tank

Tank: 20 gallons
Standard size: 24 × 12 × 16 inches, about 225 lbs when full.
See tanks on Amazon
Heater: 75 watts
Holds 20 gallons at 76°F in a 68°F room.
See heaters on Amazon
Hang-on-back filter: 100+ gallons per hour
Turns the tank over about 5 times an hour.
See filters on Amazon
Aquarium sand: 25 lbs
A 1.5-inch layer. Sand protects bottom dwellers that dig and sift.
See substrate on Amazon
LED light and lid: 24 inches long
A lid cuts evaporation and stops fish and snails getting out.
See lights on Amazon

Starter supplies

Water conditioner
Removes chlorine from tap water. Roughly 2 mL per full fill; follow your bottle's label.
See on Amazon
Liquid water test kit
For cycling the tank before fish go in, and for checking water after.
See on Amazon
Thermometer
A heater's dial is only a rough guide.
See on Amazon
Gravel vacuum
For weekly water changes of about 5 gallons (25%).
See on Amazon
Sinking wafers for bottom feeders
For your corydoras.
See on Amazon

Paid links. As an Amazon Associate, TankStarter earns from qualifying purchases. Sizes are estimates from published care guidelines, not hands-on testing.

Corydoras catfish tank mates

These share a temperature range and temperament with corydoras, with no warnings from our checks.

Use caution with: fancy goldfish. Add them in the builder to see why.

Plan a tank around corydoras

Add tank mates, check the stocking level and get the equipment sized for your tank.

Open the tank builder

Corydoras catfish questions

What size tank does a corydoras catfish need?

At least 20 gallons for a group of 6. A larger tank is more stable and gives you more choice of tank mates.

How many corydoras can I keep in a 20-gallon tank?

Up to about 12 if they are the only species in the tank. Fewer if you add other fish.

Do corydoras need a heater?

Usually yes. Corydoras catfish does best at 72–79°F, which is warmer than most rooms. A 20-gallon tank needs about 75 watts in a 68°F room.

What fish can live with corydoras?

Good matches include bettas, neon tetras, cardinal tetras, ember tetras, rummy-nose tetras, black skirt tetras. They share a temperature range and temperament with corydoras.