Fish compatibility checker
Two fish, one answer. The pair is judged in a very large tank, so tank size is not hiding the problem: what is left is temperament, mouth size, water temperature and chemistry, and whether each fish has the group it needs.
Choose two fish, or press a square in the grid below.
The twelve most asked about
Works Depends Avoid
| Black Skirt Tetra | Bronze Corydoras | Cardinal Tetra | Cherry Barb | Dwarf Gourami | Freshwater Angelfish | Goldfish | Green Swordtail | Guppy | Harlequin Rasbora | Kuhli Loach | Molly | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Black Skirt Tetra | Same fish | |||||||||||
| Bronze Corydoras | Same fish | |||||||||||
| Cardinal Tetra | Same fish | |||||||||||
| Cherry Barb | Same fish | |||||||||||
| Dwarf Gourami | Same fish | |||||||||||
| Freshwater Angelfish | Same fish | |||||||||||
| Goldfish | Same fish | |||||||||||
| Green Swordtail | Same fish | |||||||||||
| Guppy | Same fish | |||||||||||
| Harlequin Rasbora | Same fish | |||||||||||
| Kuhli Loach | Same fish | |||||||||||
| Molly | Same fish |
Pairs in this set that need care
- Avoid: Black Skirt Tetra with Dwarf Gourami. Black Skirt Tetra nips fins and Dwarf Gourami has fins worth nipping.
- Avoid: Black Skirt Tetra with Freshwater Angelfish. Black Skirt Tetra nips fins and Freshwater Angelfish has fins worth nipping.
- Avoid: Black Skirt Tetra with Goldfish. Black Skirt Tetra nips fins and Goldfish has fins worth nipping.
- Avoid: Black Skirt Tetra with Guppy. Black Skirt Tetra nips fins and Guppy has fins worth nipping.
- Avoid: Cardinal Tetra with Goldfish. Temperature ranges do not overlap: Cardinal Tetra needs 24 °C or more, Goldfish needs 22 °C or less.
- Avoid: Cardinal Tetra with Green Swordtail. pH ranges do not overlap: Green Swordtail needs 7 or more, Cardinal Tetra needs 6.8 or less.
- Avoid: Cardinal Tetra with Guppy. pH ranges do not overlap: Guppy needs 7 or more, Cardinal Tetra needs 6.8 or less.
- Avoid: Cardinal Tetra with Molly. pH ranges do not overlap: Molly needs 7.2 or more, Cardinal Tetra needs 6.8 or less.
- Avoid: Cherry Barb with Freshwater Angelfish. Freshwater Angelfish will eat Cherry Barb: at 4.5 cm it is under the 5.3 cm a full-grown Freshwater Angelfish can swallow.
- Avoid: Cherry Barb with Goldfish. Temperature ranges do not overlap: Cherry Barb needs 23 °C or more, Goldfish needs 22 °C or less.
- Avoid: Dwarf Gourami with Goldfish. Temperature ranges do not overlap: Dwarf Gourami needs 23 °C or more, Goldfish needs 22 °C or less.
- Avoid: Freshwater Angelfish with Goldfish. Temperature ranges do not overlap: Freshwater Angelfish needs 24 °C or more, Goldfish needs 22 °C or less.
- Avoid: Freshwater Angelfish with Guppy. Freshwater Angelfish with Guppy: Angelfish nip the long tails and can eat small guppy fry or young adults.
- Avoid: Freshwater Angelfish with Harlequin Rasbora. Freshwater Angelfish will eat Harlequin Rasbora: at 4.5 cm it is under the 5.3 cm a full-grown Freshwater Angelfish can swallow.
- Avoid: Goldfish with Guppy. Goldfish with Guppy: Different temperature needs, and goldfish will eat guppy fry and bully fancy-tailed males.
- Avoid: Goldfish with Harlequin Rasbora. Goldfish will eat Harlequin Rasbora: at 4.5 cm it is under the 6.3 cm a full-grown Goldfish can swallow.
- Avoid: Goldfish with Kuhli Loach. Temperature ranges do not overlap: Kuhli Loach needs 24 °C or more, Goldfish needs 22 °C or less.
- Avoid: Goldfish with Molly. Temperature ranges do not overlap: Molly needs 24 °C or more, Goldfish needs 22 °C or less.
- Avoid: Kuhli Loach with Molly. Hardness ranges do not overlap: Molly needs 12 dGH or more, Kuhli Loach needs 10 dGH or less.
- Depends: Black Skirt Tetra with Bronze Corydoras. Bronze Corydoras is above its minimum school of 6; 8 is better.
- Depends: Black Skirt Tetra with Cardinal Tetra. Cardinal Tetra is above its minimum school of 8; 15 is better.
- Depends: Black Skirt Tetra with Cherry Barb. Cherry Barb is above its minimum school of 6; 8 is better.
- Depends: Black Skirt Tetra with Green Swordtail. Black Skirt Tetra is above its minimum school of 6; 8 is better.
- Depends: Black Skirt Tetra with Harlequin Rasbora. Harlequin Rasbora is above its minimum school of 8; 12 is better.
- Depends: Black Skirt Tetra with Kuhli Loach. Kuhli Loach is above its minimum school of 6; 8 is better.
- Depends: Black Skirt Tetra with Molly. pH overlap is only 7.2 to 7.5, set by Molly and Black Skirt Tetra.
- Depends: Bronze Corydoras with Cardinal Tetra. Cardinal Tetra is above its minimum school of 8; 15 is better.
- Depends: Bronze Corydoras with Cherry Barb. Cherry Barb is above its minimum school of 6; 8 is better.
- Depends: Bronze Corydoras with Dwarf Gourami. Bronze Corydoras is above its minimum school of 6; 8 is better.
- Depends: Bronze Corydoras with Freshwater Angelfish. Bronze Corydoras is above its minimum school of 6; 8 is better.
- Depends: Bronze Corydoras with Goldfish. Temperature overlap is only 21 to 22 °C, set by Bronze Corydoras and Goldfish.
- Depends: Bronze Corydoras with Green Swordtail. Bronze Corydoras is above its minimum school of 6; 8 is better.
- Depends: Bronze Corydoras with Guppy. Bronze Corydoras is above its minimum school of 6; 8 is better.
- Depends: Bronze Corydoras with Harlequin Rasbora. Harlequin Rasbora is above its minimum school of 8; 12 is better.
- Depends: Bronze Corydoras with Kuhli Loach. Kuhli Loach is above its minimum school of 6; 8 is better.
- Depends: Bronze Corydoras with Molly. Bronze Corydoras is above its minimum school of 6; 8 is better.
- Depends: Cardinal Tetra with Cherry Barb. Cherry Barb is above its minimum school of 6; 8 is better.
- Depends: Cardinal Tetra with Dwarf Gourami. Cardinal Tetra is above its minimum school of 8; 15 is better.
- Depends: Cardinal Tetra with Freshwater Angelfish. Cardinal Tetra with Freshwater Angelfish: Cardinals are slightly larger than neons but still fit an adult angelfish mouth. Add angelfish last and keep the shoal large.
- Depends: Cardinal Tetra with Harlequin Rasbora. Harlequin Rasbora is above its minimum school of 8; 12 is better.
- Depends: Cardinal Tetra with Kuhli Loach. Kuhli Loach is above its minimum school of 6; 8 is better.
- Depends: Cherry Barb with Dwarf Gourami. Cherry Barb is above its minimum school of 6; 8 is better.
- Depends: Cherry Barb with Green Swordtail. Cherry Barb is above its minimum school of 6; 8 is better.
- Depends: Cherry Barb with Guppy. Cherry Barb is above its minimum school of 6; 8 is better.
- Depends: Cherry Barb with Harlequin Rasbora. Harlequin Rasbora is above its minimum school of 8; 12 is better.
- Depends: Cherry Barb with Kuhli Loach. Kuhli Loach is above its minimum school of 6; 8 is better.
- Depends: Cherry Barb with Molly. pH overlap is only 7.2 to 7.5, set by Molly and Cherry Barb.
- Depends: Dwarf Gourami with Freshwater Angelfish. Dwarf Gourami with Freshwater Angelfish: Gouramis can harass the angelfish or be pushed around themselves in tanks without enough hiding places.
- Depends: Dwarf Gourami with Harlequin Rasbora. Harlequin Rasbora is above its minimum school of 8; 12 is better.
- Depends: Dwarf Gourami with Kuhli Loach. Kuhli Loach is above its minimum school of 6; 8 is better.
- Depends: Dwarf Gourami with Molly. pH overlap is only 7.2 to 7.5, set by Molly and Dwarf Gourami.
- Depends: Freshwater Angelfish with Kuhli Loach. Kuhli Loach is above its minimum school of 6; 8 is better.
- Depends: Freshwater Angelfish with Molly. pH overlap is only 7.2 to 7.4, set by Molly and Freshwater Angelfish.
- Depends: Goldfish with Green Swordtail. Temperature overlap is only 21 to 22 °C, set by Green Swordtail and Goldfish.
- Depends: Green Swordtail with Harlequin Rasbora. Harlequin Rasbora is above its minimum school of 8; 12 is better.
- Depends: Green Swordtail with Kuhli Loach. pH overlap is only 7 to 7.2, set by Green Swordtail and Kuhli Loach.
- Depends: Guppy with Harlequin Rasbora. Harlequin Rasbora is above its minimum school of 8; 12 is better.
- Depends: Guppy with Kuhli Loach. pH overlap is only 7 to 7.2, set by Guppy and Kuhli Loach.
- Depends: Harlequin Rasbora with Kuhli Loach. Kuhli Loach is above its minimum school of 6; 8 is better.
- Depends: Harlequin Rasbora with Molly. pH overlap is only 7.2 to 7.5, set by Molly and Harlequin Rasbora.
What the answer means
Works means the data finds nothing against the pairing. Depends means it can work if you meet a condition, usually a bigger group, more hiding places or a longer tank, and the reason is given. Avoid means one fish will harm or eat the other, or their water needs do not overlap.
A pair that works is not a whole stock that works. Put the full list in the planner to check space, load, water and group together, or read how the checks are made. Each fish has its own page of tankmates under all fish.