Compatibility Overview
Keyhole Cichlid and Lemon Tetra 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 40 gallons), dense planting, and close monitoring are essential.
| Factor | Keyhole Cichlid | Lemon Tetra | Verdict |
|---|---|---|---|
| Temperature | 72–79°F | 72–82°F | ✅ 72–79°F |
| pH Range | 7.0–8.0 | 6.0–7.5 | ⚠️ 7.0–7.5 (narrow) |
| Temperament | semi | aggressive | ❌ Risk |
| Adult Size | 2.0 in | 1.6 in | ✅ Similar |
| Min. Group | 1+ | 6+ | See below |
| Min. Tank Size | 40 gallons (for both species) | — | |
✅ Compatibility Positives
⚠️ Caution Points
Species Profiles
Keyhole Cichlid — Aquarium species
The Keyhole Cichlid is a popular choice for beginners due to its relatively easy care and peaceful temperament. These fish are known for their distinct keyhole marking and vibrant coloration. They do well in a community tank with other peaceful species, but should be provided with plenty of hiding spots to feel secure. With proper care, they can live for sev
→ Full Keyhole Cichlid care guide
Lemon Tetra — Aquarium species
The Lemon Tetra is a vibrant, peaceful addition to freshwater tanks. Known for its striking yellow and red colors, it is well-suited for community tanks. They are active swimmers and thrive in groups. Maintaining stable water conditions is key to their health.
Frequently Asked Questions
Can Keyhole Cichlid live with Lemon Tetra?
With significant caution and a larger tank. Keyhole Cichlid and Lemon Tetra 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 40 gallons), dense planting, and close monitoring are essential.
What tank size do I need for Keyhole Cichlid and Lemon Tetra together?
A minimum of 40 gallons is recommended for keeping Keyhole Cichlid and Lemon Tetra together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Keyhole Cichlid and Lemon Tetra?
72–79°F
Is a Keyhole Cichlid aggressive toward a Lemon Tetra?
Keyhole Cichlid is semi and Lemon Tetra is aggressive. No major aggression issues are expected between these species.
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 | 50/100 |
| 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 | 40 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 55 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 90 gal | Best when keeping larger schools or reducing territorial pressure. |