Compatibility Overview
Peacock Cichlid and Threadfin Rainbowfish 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 29 gallons), dense planting, and close monitoring are essential.
| Factor | Peacock Cichlid | Threadfin Rainbowfish | Verdict |
|---|---|---|---|
| Temperature | 75–81°F | 72–82°F | ✅ 75–81°F |
| pH Range | 7.5–8.5 | 6.5–7.5 | ⚠️ 7.5–7.5 (narrow) |
| Temperament | aggressive | semi | ❌ Risk |
| Adult Size | 3.1 in | 2.0 in | ✅ Similar |
| Min. Group | 1+ | 1+ | See below |
| Min. Tank Size | 29 gallons (for both species) | — | |
✅ Compatibility Positives
⚠️ Caution Points
Species Profiles
Peacock Cichlid — Aquarium species
The Peacock Cichlid, Aulonocara nyassae, is a stunning fish with vibrant blue and yellow colors. These fish are known for their aggression and require a mature and well-maintained tank. They are best kept in pairs or in a species-specific tank. Careful attention must be given to water parameters and tank setup to ensure their health and well-being.
→ Full Peacock Cichlid care guide
Threadfin Rainbowfish — Aquarium species
The Threadfin Rainbowfish is a popular choice for freshwater aquariums due to its vibrant colors and peaceful nature. It requires a well-maintained tank with plenty of swimming space and a moderate water flow. These fish are not known to be aggressive and can be kept in community tanks with other peaceful species. Regular water changes and a balanced diet ar
Frequently Asked Questions
Can Peacock Cichlid live with Threadfin Rainbowfish?
With significant caution and a larger tank. Peacock Cichlid and Threadfin Rainbowfish 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 29 gallons), dense planting, and close monitoring are essential.
What tank size do I need for Peacock Cichlid and Threadfin Rainbowfish together?
A minimum of 29 gallons is recommended for keeping Peacock Cichlid and Threadfin Rainbowfish together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Peacock Cichlid and Threadfin Rainbowfish?
75–81°F
Is a Peacock Cichlid aggressive toward a Threadfin Rainbowfish?
Peacock Cichlid is aggressive and Threadfin Rainbowfish 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 | 25/100 |
| Adult Size | 100/100 |
| Swim Zone | 68/100 |
| 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 | 29 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 40 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 55 gal | Best when keeping larger schools or reducing territorial pressure. |