Yes: Compatible.
No clashes under our rules: they share a temperature range, neither is a fin nipper or predator of the other, and their temperaments fit.
Temperature. Guppy does best at 18–28 °C (64–82 °F) and Peppered corydoras at 22–26 °C (72–79 °F). They share 22–26 °C.
Water. Their pH ranges overlap at 7–7.
Temperament and size. Guppy is peaceful and grows to 6 cm; Peppered corydoras is peaceful and grows to 7 cm. Guppy swims at the top and Peppered corydoras at the bottom, which spreads them out.
Tank size and groups. Plan on at least 25 US gallons, the larger of the two cautious minimums. Keep Guppy in a group of 3+. Keep Peppered corydoras in a group of 6+. A starter mix of 3 Guppy and 6 Peppered corydoras in 25 gallons uses about 78% of the tank’s bioload capacity under our rules and grades A.
Keeping them together
- Feeding: Peppered corydoras feeds on the bottom. Add sinking pellets or wafers after lights-out so faster mid-water fish don’t take it all.
- Aquascape: both are calmer with cover. Plants and floating cover make shy fish come out more, not less.
- Group size: a full group is not optional. A schooling fish kept in too small a group is stressed and more likely to nip or hide.
- Shrimp and snails: neither is a known invertebrate eater, but baby shrimp can still be eaten. Dense moss helps.
- Adding them: add the calmer species first and let it settle for a week or two before adding the other, and only once your tank has cycled.
Open this pair in the checker Add your other fish to grade the whole tank.
Quick facts
| Guppy | Peppered corydoras | |
|---|---|---|
| Adult size | 6 cm | 7 cm |
| Min tank | 10 gal | 25 gal |
| Temperature | 18–28 °C | 22–26 °C |
| pH | 7–8 | 6.5–7 |
| Temperament | peaceful | peaceful |
| Group size | 3+ | 6+ |
Data from the Species Ledger, checked November 9, 2026, with at least two sources per species. Cautious community guidelines, not guarantees: individual fish vary. Not veterinary advice. Disagree? Tell us.