Keyhole Cichlid and Oscar Compatibility Overview
Keyhole Cichlid and Oscar are generally not recommended to be housed together. The adult size gap creates a meaningful predation risk. Keyhole Cichlid is peaceful and Oscar is aggressive. Expect chasing and fin damage unless the tank is oversized, heavily planted, and watched closely. Review the behavior and water details before deciding whether to attempt the pairing.
| Factor | Keyhole Cichlid | Oscar | Verdict |
|---|---|---|---|
| Temperature | 70โ82ยฐF | 74โ81ยฐF | โ 74โ81ยฐF |
| pH Range | 4.0โ7.5 | 6.0โ8.0 | โ 6.0โ7.5 |
| Temperament | peaceful | aggressive | โ Risk |
| Adult Size | 4.3 in | 14 in | โ ๏ธ 3.3ร difference |
| Min. Group | 2+ | 1+ | See below |
| Min. Tank Size | 100 gallons (for both species) | โ | |
Compatibility Positives
Incompatibility Reasons
Species Profiles
Keyhole Cichlid โ Cleithracara maronii
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.
โ Full Keyhole Cichlid care guide
Oscar โ Astronotus ocellatus
Intelligent but aggressive cichlids that will eat any fish small enough to fit in their mouth. Require large tanks (75+ gallons) and robust tank mates.
Frequently Asked Questions
Can Keyhole Cichlid live with Oscar?
Generally not recommended. Keyhole Cichlid and Oscar are generally not recommended to be housed together. The adult size gap creates a meaningful predation risk. Keyhole Cichlid is peaceful and Oscar is aggressive. Expect chasing and fin damage unless the tank is oversized, heavily planted, and watched closely. Review the behavior and water details before deciding whether to attempt the pairing.
What tank size do I need for Keyhole Cichlid and Oscar together?
A minimum of 100 gallons is recommended for keeping Keyhole Cichlid and Oscar together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Keyhole Cichlid and Oscar?
74โ81ยฐF โ inside Keyhole Cichlid's 70โ82ยฐF and Oscar's 74โ81ยฐF.
Is a Keyhole Cichlid aggressive toward a Oscar?
The adult size gap creates a meaningful predation risk.
Related Compatibility Guides
Tank Size for Keyhole Cichlid and Oscar
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 100 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 150 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 180 gal | Best when keeping larger schools or reducing territorial pressure. |