Can Molly Live With Guppy?
good82/100
Key Takeaways
- Compatibility verdict: good (82/100).
- Use at least a 25 gallon tank for this combination.
- Risk to manage: Mollies may outcompete guppies in small tanks.
Why This Pairing Works
- Both are livebearers that prefer harder, more alkaline water
- Mollies are larger and more active than guppies
- Risk to manage: Mollies may outcompete guppies in small tanks.
- Risk to manage: Breeding can increase stocking quickly.
Minimum Viable Setup
| Tank | At least 25 gallons; more room is needed for active, territorial, or schooling fish. |
|---|---|
| Temperature | 24-28°C shared range |
| Groups | Molly: 3+; Guppy: 3+. |
| Cover and space | Use hard, alkaline water if possible |
| Observation risk | Mollies may outcompete guppies in small tanks |
Compatibility Score Breakdown
Temperature Overlap
90
pH Overlap
85
Temperament
85
Size Risk
90
Swimming Level
85
Diet Conflict
95
Minimum Tank Size
Use at least a 25 gallon tank for this combination.
Setup Tips
- Use hard, alkaline water if possible
- Provide swimming space for mollies
- Monitor male chasing behavior
Works Best If
- The tank is at least 25 gallons and fully cycled.
- Both species have hiding space and are introduced with close observation.
- Water temperature and pH stay inside the overlap shown in the score breakdown.
Main Risks
- Mollies may outcompete guppies in small tanks
- Breeding can increase stocking quickly
Avoid This Pairing If
- The tank is smaller than the recommended minimum.
- Either species is already showing stress, hiding, or fin damage.
- You cannot separate the fish quickly if chasing, nipping, or bullying starts.
Frequently Asked Questions
Can mollies live with guppies?
Yes, usually. They share similar water preferences, but mollies need more space and can be pushier in small tanks.
Related Tools
Sources and Review Process
- Freshwater aquarium husbandry references for water quality, tank size, and stocking guidance.
- Species profiles and compatibility rules maintained in the AquaScience AI data set.
- Aquarium health guidance is educational and should not replace an aquatic veterinarian for severe symptoms.
Related Compatibility Guides
Molly Care Guide
Tank size, diet, water parameters, and common care notes for Molly.
Guppy Care Guide
Tank size, diet, water parameters, and common care notes for Guppy.
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