Compatibility Overview
Keyhole Cichlid and Otocinclus can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges, and neither poses a major aggression risk to the other. A minimum 29-gallon tank is recommended to provide adequate territory and water volume for both species.
| Factor | Keyhole Cichlid | Otocinclus | 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 | peaceful | ⚠️ Monitor |
| Adult Size | 2.0 in | 1.5 in | ✅ Similar |
| Min. Group | 1+ | 4+ | See below |
| Min. Tank Size | 29 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
Otocinclus — 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 Keyhole Cichlid live with Otocinclus?
Yes, in a well-planned setup. Keyhole Cichlid and Otocinclus can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges, and neither poses a major aggression risk to the other. A minimum 29-gallon tank is recommended to provide adequate territory and water volume for both species.
What tank size do I need for Keyhole Cichlid and Otocinclus together?
A minimum of 29 gallons is recommended for keeping Keyhole Cichlid and Otocinclus together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Keyhole Cichlid and Otocinclus?
72–79°F
Is a Keyhole Cichlid aggressive toward a Otocinclus?
Keyhole Cichlid is semi and Otocinclus is peaceful. 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 | 75/100 |
| 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 | 75 gal | Best when keeping larger schools or reducing territorial pressure. |