Bronze Corydoras
Corydoras aeneus
Social bottom-dweller for peaceful community tanksBeginner
- Lifespan
- 5-10 years
- Size
- 6-7 cm (2.5-3 in)
- Social needs
- Highly social - keep 6+ together
- Time
- Low-moderate (daily feed, weekly water changes)
- Cost
- Low
- Diet
- Omnivore (bottom-feeder)
Overview
What is this animal?
- The Bronze Corydoras is a peaceful, armoured catfish from South America and one of the most popular bottom-dwellers in the hobby.
- Hardy and long-lived, it scours the substrate and brings constant gentle activity to the lower tank.
- Despite a reputation as a clean-up crew, this is not a fish that survives on leftovers.
- It is a genuine community species with real social and dietary needs that keepers must meet.
Temperament
- Bronze Corydoras are sociable and peaceful, and are happiest and most active in a shoal of six or more of their own kind.
- Kept singly or in pairs they become withdrawn, whereas a proper group displays its characteristic collective foraging and resting.
- They coexist well with most calm community fish, including tetras, rasboras, dwarf cichlids, and peaceful barbs.
- Their gentle nature means they should not be mixed with aggressive or large predatory tankmates.
A good fit for
- Beginners wanting an active bottom-dweller
- Peaceful community aquariums
- Keepers using sand substrate
- Long-term hobbyists (often 5-10 years)
Common mistakes to avoid
- Keeping fewer than 6 (they are social)
- Sharp gravel eroding their barbels
- Assuming they survive on leftovers
- Copper/salt medications they tolerate poorly
Enclosure
Minimum 75 litres (20 US gallons) — for a group of 6
Cannot be kept alone. The minimum is 6, and the space above is for that group.
- Keep a group in a tank of at least 75 litres (20 gallons) with a soft sand or smooth, rounded fine-gravel substrate to protect their delicate barbels.
- Target 22-26C (72-79F), pH 6.0-7.5, in a fully cycled, well-oxygenated setup.
- Provide shaded spots, plants, and driftwood for security.
- They periodically dash to the surface to gulp air, so leave an air gap beneath a tight lid.
- Sharp or coarse gravel erodes barbels and invites infection.
Supplies
Setup
- Tank and stand
- Filter
- Heater and thermometer
- Substrate, plants and decor
- Liquid test kit
- Dechlorinator and starter supplies
Ongoing
- Sinking wafers or tablets for bottom-feeders
- Algae or spirulina wafers
- Frozen bloodworm, daphnia and brine shrimp
- Untreated aquarium driftwood (essential for clown plecos)
- Courgette, cucumber and spinach for blanching
- Veg clip or a stainless veg skewer
- Feeding tongs or a pipette for target-feeding
- Fine sand substrate for corydoras foraging
Safe substrate: Inert aquarium gravel · Fine, smooth sand · Aquasoil for planted tanks
Care routine
Daily
- Check temperature and equipment
- Head-count and look everyone over
- Sinking food at lights-out
Weekly
- Top up evaporationevery 3 days
- Check belly profiles
- Clean glass and clear algae
- Test the water
- Water change and gravel vacuum
Monthly
- Trim and thin the plantsevery 2 weeks
- Check supplies and reagent dates
- Check the driftwood
- Rinse the filter media
Less often
- Replace chemical filter media (Carbon/Purigen)every 2 months
Vet: Quarterly bottom-dweller review — every 3 months
Top resources for more info
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Diet
- Bronze Corydoras are omnivores that should be fed directly, not left to scavenge.
- Use sinking pellets, wafers, and tablets that reach the bottom, supplemented with frozen or live bloodworm, daphnia, and brine shrimp.
- Feed once or twice daily, making sure enough food sinks past faster mid-water fish so the cories actually eat.
- Slow starvation from relying on scraps is a common cause of decline; a proper sinking diet keeps them well-rounded and healthy.
Health
- These catfish are robust but vulnerable to two husbandry faults: barbel erosion from sharp or dirty substrate, and red blotch or fin infections in poor water.
- Keeping the substrate clean and parameters stable prevents most problems.
- They are also sensitive to high nitrate and to salt and copper-based medications, so dose carefully.
- Watch barbel length, breathing rate, and skin condition, and quarantine new fish.
- With good care, individuals routinely live well beyond five years.
Is your enclosure big enough?
Is this urgent?
In a fish tank the patient is usually the water. Test before you treat — dosing a healthy tank for a disease it does not have makes things worse.
Go now
Today
Soon
Never add a new fish to a tank that is not fully cycled, and never treat blind. A test kit is cheaper than the fish.
This is general guidance for a healthy adult, not a diagnosis. An exotics vet who knows your animal always overrides it — and the time to find one is before you need one.
What it really costs
Setup, monthly, first year and across a whole life, itemised and with the electricity worked out from the actual wattage. Published figures for the same animal disagree by a factor of four, so the calculator shows ranges rather than picking one.
Bedding and substrate
Substrate in an aquarium is a filter as much as a floor. Most of the biology lives in and on it.
Safe
With a caveat
Never
This is our general list for freshwater fish. We have not built one specific to Catfish yet.
My kit says 0.25 ppm. Is that dangerous?
A liquid kit measures total ammonia, but only the un-ionised fraction is really toxic, and that fraction is governed by pH and temperature — each whole pH unit multiplies it roughly tenfold. So the same reading can be nearly harmless in one tank and lethal in another; this works out which one you are in.
Compare with other animals
The same axes for every animal, side by side — the way the guides are written makes that a fair comparison rather than two articles.
Catfish, side by side
Same axes, same care guides — the honest way to choose between types.
See all Catfish side by side →
