Discus and Pygmy Corydoras: Can They Live Together?
Side-by-side comparison
| Factor | Discus | Pygmy Corydoras | Assessment |
|---|---|---|---|
| Water temperature | 82–88°F | 72–79°F | No overlap |
| pH | 5.5–7 | 6.2–7.4 | Overlap 6.2–7 |
| Hardness | 1–8 dGH | 2–12 dGH | Overlap 2–8 dGH |
| Adult size | 8.0″ | 1.0″ | 8.0× difference |
| Temperament | Peaceful | Peaceful | Both peaceful |
| Swim level | Mid | All | Different zones |
| Minimum tank | 55 gal | 10 gal | Together: 61 gal+ |
Shared water parameters
- No shared temperature window.
- pH both tolerate: 6.2–7
- Hardness both tolerate: 2–8 dGH
- Recommended combined tank: 61 gallons or larger
Risks and things to watch
Size mismatch — predation risk
Discus reaches 8.0″ while Pygmy Corydoras tops out at 1.0″. As a rough rule, anything that fits in another fish's mouth eventually will. This is the main reason this pairing needs care.
Temperature conflict
The comfortable ranges barely meet. Running one species at the edge of its range for months is a slow-burn health problem, not an instant one — which is why it often goes unnoticed.
Group requirements
Compatibility is not only about the two species getting along — each still needs its own social setup met inside the same tank.
- Discus — minimum group of 5. Budget tank space for the whole shoal, not one fish.
- Pygmy Corydoras — minimum group of 8. Budget tank space for the whole shoal, not one fish.
Frequently asked questions
Can discus and pygmy corydoras live together?
Not recommended. We do not recommend housing Discus with Pygmy Corydoras. The conflicts below are structural — they are not solved by a bigger tank or more plants. Choose a different tank mate instead.
What size tank do discus and pygmy corydoras need together?
Plan for at least 61 gallons. Discus alone needs 55 gallons and Pygmy Corydoras needs 10, but combined stocking needs headroom for filtration and swimming space, not just volume.
What temperature suits both species?
There is no shared comfortable range: Discus needs 82–88°F and Pygmy Corydoras needs 72–79°F. That alone rules the pairing out.
What pH works for both?
Aim for pH 6.2–7, which sits inside both species' comfortable range.
Will discus eat pygmy corydoras?
It is a real risk. The size difference is 8.0×, and anything that fits in a fish's mouth is eventually treated as food.
How should the tank be arranged?
Use plants, wood and rock to break sight lines, keep open swimming space along the front, and add the more territorial species last so it cannot claim the whole tank before the other settles in.
Explore further
Assessment generated from our compatibility methodology: parameter overlap, adult size ratio, temperament and swimming zone. Reviewed by Marcus Rivera.