Group of bronze Corydoras catfish swimming over a planted aquarium carpet

Corydoras Catfish Care Guide: Food, Tank Setup & Tankmates

January 24 2023, by Elmarie Seymour, 10 min reading time

Corydoras are peaceful, playful bottom-dwellers, but they are not a cleanup crew. How to set up their tank, what to feed them and which fish to keep them with.

Updated October 2026 · Written by the Dorry Pets team in Centurion

Corydoras catfish (Corys, or Cory cats) are among the most loved community fish for good reason. They're peaceful, small, busy all day and full of character: they shuffle along the bottom in little groups, wink at you (they really do roll their eyes) and dart to the surface for a gulp of air. They're a great choice for a first tropical tank and still a favourite with experienced fishkeepers.

They're often sold as a "cleanup crew", but that's where many Corys run into trouble. Corydoras will eat food that sinks past the other fish, but they can't live on leftovers and they don't clean the tank. They need their own food, soft sand and clean water. This guide covers everything you need to keep them healthy, with South African conditions in mind.

Corydoras quick facts

Adult size	2.5–7 cm for most species
Group size	6 or more of the same species
Temperature	22–26 °C for most species (peppered Corys cope with cooler water; sterbai prefer 24–28 °C)
pH	About 6.0–7.8. Stable water matters more than an exact number
Minimum tank	60 cm long (around 54 litres) for a group of small Corys
Substrate	Soft sand or smooth, rounded gravel
Diet	Omnivore: sinking wafers or pellets plus frozen foods
Temperament	Peaceful, safe with most community fish
Lifespan	Often 5–10 years with good care

Popular Corydoras species

There are more than 160 described Corydoras species, plus many more still waiting for a scientific name. These are the ones you're most likely to find in South African fish shops:

Bronze Corydoras (Corydoras aeneus), including the albino form. Hardy, up to about 7 cm and one of the best Corys for beginners.
Peppered Corydoras (Corydoras paleatus). Mottled grey-green, about 6 cm, and happier than most in slightly cooler water.
Panda Corydoras (Corydoras panda). White with black eye and tail patches, about 5 cm. A little more sensitive, so add them to a mature tank.
Sterbai Corydoras (Corydoras sterbai). Dark with white spots and orange fins, about 6–7 cm. Likes warmer water, so it's a good match for discus and rams.
Julii / Three-stripe Corydoras (Corydoras trilineatus). Spotted and striped, about 5–6 cm. Most "julii" in the hobby are actually trilineatus.
Pygmy Corydoras (Corydoras pygmaeus). Only about 2.5 cm, swims in mid-water as well as on the bottom, and is perfect for nano and planted tanks in groups of 10 or more.

Which species are available changes from shipment to shipment. See what's in stock on our latest livestock shipment list.

Setting up a Corydoras tank

Choose the right substrate

Corys search for food with the sensitive whiskers (barbels) around their mouths, pushing their faces into the bottom all day. Sharp or dirty gravel wears these barbels down, and damaged barbels can become infected. Fine, soft sand is ideal because it lets them forage naturally, and you'll see far more of their natural behaviour. Smooth, rounded gravel is the next best option.

Good choices are ADA La Plata Sand and ADA Colorado Sand, or browse our full aquarium sand range. Avoid crushed coral and aragonite sands in a Cory tank; they're made for marine tanks and push pH up.

ADA La Plata Sand: fine, smooth grains that are gentle on Cory barbels.

Plants, hiding places and open space

Give your Corys an open patch of sand to dig in, with plants, driftwood or caves around the edges so they can rest out of sight. Live plants help keep the water clean and make Corys feel secure. Easy options such as Java fern, Anubias and Cryptocoryne work well. Take a look at our aquatic plants, and read more about why live plants help your aquarium.

Filtration and water flow

Corydoras come from slow-moving streams and flooded areas, so they like clean, well-oxygenated water without strong currents. Choose a filter rated for your tank size and leave space at the surface. Corys breathe air through their gut as well as their gills, and they regularly dart up for a quick gulp. That's normal. Constant gasping at the surface is not (see "Common problems" below).

Water quality and temperature in South Africa

Corys are hardy once settled, but they don't like sudden changes. A few simple habits keep them healthy:

Always dechlorinate tap water. Municipal water contains chlorine or chloramine, which harms fish and the good bacteria in your filter.
Change 20–30% of the water weekly and vacuum the sand lightly so waste doesn't build up where your Corys feed.
Test regularly. Corys are sensitive to nitrite and high nitrate. 6-in-1 aquarium test strips give you a quick check of nitrate, nitrite, pH and hardness. Our guide to improving aquarium water quality has more tips.
Only add Corys to a cycled tank, and acclimatise them slowly. They're one of the first fish to suffer in a brand-new setup.

Do Corydoras need a heater? In most South African homes, yes. On the Highveld, indoor tanks can drop well below 20 °C on winter nights. Most Corydoras do best at a steady 22–26 °C, so a reliable aquarium heater set to about 24 °C is worth it. Peppered Corys tolerate cooler water than most, while sterbai need it warmer.

During power cuts: keep the lid closed, cover the tank with a blanket to hold in heat, skip feeding until the power is back, and run a battery-powered air pump if you have one.

A note on medication: Corydoras and other catfish are more sensitive than most fish to some treatments, including salt and copper-based medications. Always read the label for catfish or scaleless-fish warnings, and ask us before treating a tank with Corys in it.

What do Corydoras eat?

Corydoras are omnivores. In the wild they eat insect larvae, worms, small crustaceans and plant matter. In your tank, give them food that sinks straight to the bottom, because flakes are usually eaten by faster fish before they get there.

Everyday staple: small sinking wafers or pellets. Hikari Micro Wafers are tiny wafers that slowly sink to the bottom and suit small mouths, and Ocean Nutrition Tropical Wafers are made for bottom-feeding catfish like Corys.
Veg now and then: Hikari Algae Wafers once or twice a week add plant matter to their diet.
Treats: frozen foods 2–3 times a week. Corys love frozen bloodworms. Thaw a small piece in a cup of tank water first. Browse our frozen foods and dry foods for more options.

Hikari Micro Wafers: small sinking wafers that reach the bottom, where Corys feed.

How much and when? Feed once or twice a day, only what the group finishes within about 15 minutes. Corys are most active at dusk, so dropping food in just before the lights go off makes sure it reaches them, not the other fish. Remove any leftovers within a few hours. Too much food is the most common cause of poor water. Read the dangers of overfeeding fish.

How many Corydoras should you keep?

Keep at least 6 of the same species, and more if your tank allows. Corys are shoaling fish: in a proper group they're confident, active and out in the open. Kept alone or in pairs, they tend to hide and stress easily. Different species will often mix, but each fish is happiest with plenty of its own kind.

Best tankmates for Corydoras

Good tankmates: neon and cardinal tetras, rasboras, guppies, platies, mollies, peaceful gouramis (honey and pearl), otocinclus, bristlenose plecos, and adult shrimp. Corys may eat baby shrimp.

Avoid: goldfish (they need cooler water and outgrow most Cory tanks), large or aggressive cichlids, and any fish big enough to fit a Cory in its mouth.

Breeding Corydoras

Bronze and peppered Corys often breed in home aquariums. Females are rounder and wider than males, especially when viewed from above. Spawning is often triggered by a large, slightly cooler water change. The pair forms a "T-position", and the female then sticks eggs to the glass, plants or décor. If you want to raise the fry, move the eggs (or the leaf they're on) to a separate container with water from the tank, and feed the fry finely crushed micro wafers once they're free-swimming.

Common Corydoras problems

Short or worn-down barbels: usually sharp or dirty substrate. Switch to sand and vacuum regularly.
Constant gasping or racing to the surface: low oxygen or poor water quality. Test the water, do a partial water change and add surface movement.
Hiding all the time and clamped fins: often too few Corys, bullying tankmates or stress from water changes. Check the group size and your water results.
Not eating: the food isn't reaching them. Use sinking foods and feed near lights-out.

Corydoras FAQs

Do Corydoras clean the tank?

Not really. They eat food that falls to the bottom, but they also produce waste and need their own food. You still need to vacuum the substrate and change water regularly.

How many Corydoras should be kept together?

At least 6 of the same species. Bigger groups behave more naturally and are more fun to watch.

What is the best food for Corydoras?

A good-quality sinking wafer or pellet as the daily staple (such as Hikari Micro Wafers), with frozen bloodworms or other frozen foods a few times a week.

Can Corydoras live with shrimp?

Yes. Adult shrimp are safe with Corys, but baby shrimp may get eaten. Plenty of moss and plants give shrimplets places to hide.

Can Corydoras live with goldfish?

It's not recommended. Goldfish prefer cooler water, grow much larger and produce a lot of waste.

How big do Corydoras get?

Most species reach 2.5–7 cm. Pygmy Corydoras stay around 2.5 cm, while bronze and sterbai Corys can reach about 7 cm.

Shop this guide

Hikari Micro Wafers: small sinking wafers sized for Corydoras
Ocean Nutrition Tropical Wafers: an everyday sinking staple
Hikari Algae Wafers: plant matter once or twice a week
Ruto Frozen Bloodworms: a favourite protein treat
ADA La Plata Sand or ADA Colorado Sand: soft sand that protects barbels
6-in-1 Aquarium Test Strips: quick weekly water checks
Aquarium heaters and live aquatic plants

Looking for Corydoras? We bring in live fish in regular shipments to our Centurion store. Check the latest shipment list or contact us and we'll let you know what's available and help you choose the right species for your tank.