Molly and Silver Arowana Compatibility Overview
Molly and Silver Arowana are generally not recommended to be housed together. The adult size gap creates a meaningful predation risk. Their usable pH overlap is narrow and requires stable, tested water. Review the behavior and water details before deciding whether to attempt the pairing.
| Factor | Molly | Silver Arowana | Verdict |
|---|---|---|---|
| Temperature | 72โ82ยฐF | 68โ86ยฐF | โ 72โ82ยฐF |
| pH Range | 7.5โ8.5 | 5.0โ7.5 | โ ๏ธ 7.5โ7.5 (narrow) |
| Temperament | peaceful | aggressive | โ Risk |
| Adult Size | 4 in | 31.5 in | โ 8ร difference |
| Min. Group | 3+ | 1+ | See below |
| Min. Tank Size | 100 gallons (for both species) | โ | |
Compatibility Positives
Incompatibility Reasons
Species Profiles
Molly โ Poecilia sphenops
Hardy livebearers that prefer alkaline, hard water โ sometimes slightly brackish. Prolific breeders; peaceful community fish.
Silver Arowana โ Osteoglossum bicirrhosum
The Silver Arowana is a majestic and unique fish known for its striking appearance and size. It is a large, predatory fish that requires a spacious tank and specific water conditions. While not a community fish, it can be kept with compatible, larger species. They are sensitive to stress and require careful water quality management.
Frequently Asked Questions
Can Molly live with Silver Arowana?
Generally not recommended. Molly and Silver Arowana are generally not recommended to be housed together. The adult size gap creates a meaningful predation risk. Their usable pH overlap is narrow and requires stable, tested water. Review the behavior and water details before deciding whether to attempt the pairing.
What tank size do I need for Molly and Silver Arowana together?
A minimum of 100 gallons is recommended for keeping Molly and Silver Arowana together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Molly and Silver Arowana?
72โ82ยฐF โ inside Molly's 72โ82ยฐF and Silver Arowana's 68โ86ยฐF.
Is a Molly aggressive toward a Silver Arowana?
The adult size gap creates a meaningful predation risk.
Related Compatibility Guides
Tank Size for Molly and Silver Arowana
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 250 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 350 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 450 gal | Best when keeping larger schools or reducing territorial pressure. |