Lionfish and Molly Compatibility Overview
Lionfish and Molly are generally not recommended to be housed together. One of these is a marine species and the other is not; they cannot share one aquarium. The adult size gap creates a meaningful predation risk. Review the behavior and water details before deciding whether to attempt the pairing.
| Factor | Lionfish | Molly | Verdict |
|---|---|---|---|
| Temperature | 72โ82ยฐF | 72โ82ยฐF | โ 72โ82ยฐF |
| pH Range | 8.1โ8.4 | 7.5โ8.5 | โ ๏ธ 8.1โ8.4 (narrow) |
| Temperament | aggressive | peaceful | โ Risk |
| Adult Size | 15.0 in | 4 in | โ ๏ธ 3.8ร difference |
| Min. Group | 1+ | 3+ | See below |
| Min. Tank Size | 100 gallons (for both species) | โ | |
Compatibility Positives
Incompatibility Reasons
Species Profiles
Lionfish โ Pterois volitans
Lionfish are popular saltwater aquarium fish known for their striking colors and intimidating spines. These fish require a large tank and careful attention to water parameters. Aggressive by nature, they can be harmful to smaller fish and invertebrates.
Molly โ Poecilia sphenops
Hardy livebearers that prefer alkaline, hard water โ sometimes slightly brackish. Prolific breeders; peaceful community fish.
Frequently Asked Questions
Can Lionfish live with Molly?
Generally not recommended. Lionfish and Molly are generally not recommended to be housed together. One of these is a marine species and the other is not; they cannot share one aquarium. The adult size gap creates a meaningful predation risk. Review the behavior and water details before deciding whether to attempt the pairing.
What tank size do I need for Lionfish and Molly together?
A minimum of 100 gallons is recommended for keeping Lionfish and Molly together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Lionfish and Molly?
72โ82ยฐF โ inside Lionfish's 72โ82ยฐF and Molly's 72โ82ยฐF.
Is a Lionfish aggressive toward a Molly?
The adult size gap creates a meaningful predation risk.
Related Compatibility Guides
Tank Size for Lionfish and Molly
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 120 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 180 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 220 gal | Best when keeping larger schools or reducing territorial pressure. |