Molly and Otocinclus Compatibility Overview
Molly and Otocinclus can potentially coexist, but the combination requires careful attention. Their usable pH overlap is narrow and requires stable, tested water. A larger tank (minimum 55 gallons), dense planting, and close monitoring are essential.
| Factor | Molly | Otocinclus | Verdict |
|---|---|---|---|
| Temperature | 72โ82ยฐF | 72โ82ยฐF | โ 72โ82ยฐF |
| pH Range | 7.5โ8.5 | 6.0โ7.5 | โ ๏ธ 7.5โ7.5 (narrow) |
| Temperament | peaceful | peaceful | โ Compatible |
| Adult Size | 4 in | 1.5 in | โ ๏ธ 2.7ร difference |
| Min. Group | 3+ | 4+ | See below |
| Min. Tank Size | 55 gallons (for both species) | โ | |
Compatibility Positives
Caution Points
Species Profiles
Molly โ Poecilia sphenops
Hardy livebearers that prefer alkaline, hard water โ sometimes slightly brackish. Prolific breeders; peaceful community fish.
Otocinclus โ Otocinclus spp.
Tiny algae-eating catfish that are peaceful with all species. Need established algae growth and biofilm; sensitive to ammonia.
Frequently Asked Questions
Can Molly live with Otocinclus?
With significant caution and a larger tank. Molly and Otocinclus can potentially coexist, but the combination requires careful attention. Their usable pH overlap is narrow and requires stable, tested water. A larger tank (minimum 55 gallons), dense planting, and close monitoring are essential.
What tank size do I need for Molly and Otocinclus together?
A minimum of 55 gallons is recommended for keeping Molly and Otocinclus together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Molly and Otocinclus?
72โ82ยฐF โ inside Molly's 72โ82ยฐF and Otocinclus's 72โ82ยฐF.
Is a Molly aggressive toward a Otocinclus?
Molly is peaceful and Otocinclus is peaceful. No major aggression issues are expected between these species.
Related Compatibility Guides
Tank Size for Molly and Otocinclus
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 55 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 75 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 125 gal | Best when keeping larger schools or reducing territorial pressure. |