Compatibility Overview
Molly and Sterbai Cory can potentially coexist, but the combination requires careful attention. Some combination of water parameter differences, size mismatch, or temperament issues make this pair challenging. A larger tank (minimum 55 gallons), dense planting, and close monitoring are essential.
| Factor | Molly | Sterbai Cory | Verdict |
|---|---|---|---|
| Temperature | 72–82°F | 72–79°F | ✅ 72–79°F |
| pH Range | 7.5–8.5 | 6.0–7.0 | ❌ No overlap |
| Temperament | peaceful | semi | ⚠️ Monitor |
| Adult Size | 4 in | 2.0 in | ⚠️ 2.0× difference |
| Min. Group | 3+ | 1+ | See below |
| Min. Tank Size | 55 gallons (for both species) | — | |
✅ Compatibility Positives
⚠️ Caution Points
Species Profiles
Molly — Poecilia sphenops
Hardy livebearers that prefer alkaline, hard water — sometimes slightly brackish. Prolific breeders; peaceful community fish.
Sterbai Cory — Aquarium species
The Sterbai Cory, known for its dark brown coloration with silver spots, is a popular bottom-dwelling fish. With a peaceful temperament, it is well-suited for community tanks. It requires a well-planted tank with plenty of hiding spots and moderate water flow. Regular water changes and a balanced diet are essential for their health.
Frequently Asked Questions
Can Molly live with Sterbai Cory?
With significant caution and a larger tank. Molly and Sterbai Cory can potentially coexist, but the combination requires careful attention. Some combination of water parameter differences, size mismatch, or temperament issues make this pair challenging. A larger tank (minimum 55 gallons), dense planting, and close monitoring are essential.
What tank size do I need for Molly and Sterbai Cory together?
A minimum of 55 gallons is recommended for keeping Molly and Sterbai Cory together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Molly and Sterbai Cory?
72–79°F
Is a Molly aggressive toward a Sterbai Cory?
Molly is peaceful and Sterbai Cory is semi. Their preferred pH ranges are difficult to reconcile.
Related Compatibility Guides
Compatibility score breakdown
The overall score is weighted across water chemistry, behavior, adult size, swimming zone, and social needs. A score is a planning aid—not a guarantee for individual fish.
| Factor | Score |
|---|---|
| Temperature | 100/100 |
| Ph | 0/100 |
| Temperament | 75/100 |
| Adult Size | 72/100 |
| Swim Zone | 92/100 |
| Social Needs | 92/100 |
Tank size scenarios
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. |