Cichlids · Intermediate care
Keyhole cichlid
Cleithracara maronii
Keyhole cichlid is rated intermediate here because of its adult size, water range and social needs. Plan the aquarium around adult size, territory and sight breaks rather than shop size. One of the calmer cichlids; needs cover and peaceful companions.

Is Keyhole cichlid a good aquarium fish?
Keyhole cichlid reaches about 12 cm as an adult, so plan around the adult fish rather than the juvenile size seen in shops. The suggested minimum of 40 US gallons assumes suitable filtration, open swimming space and routine maintenance.
Generally peaceful in a suitable community. Keep the recommended group of one fish or a compatible pair and avoid mixing it with tank mates that need a very different temperature, water chemistry or swimming level.
Water and aquarium setup
A stable temperature of 24–28°C and pH of 5.5–7.5 are the working ranges in the planner. Stability and clean, oxygenated water matter more than chasing a single target number.
Break up sight lines with rock, wood or plants and reserve territory before adding fish. Breeding pairs can change a peaceful community quickly.
Diet
A varied omnivore or carnivore diet of quality pellets, frozen foods and occasional treats.
Compatibility notes
One of the calmer cichlids; needs cover and peaceful companions.
Use the Stocking & Bioload Planner to check a proposed community. Its estimated bioload value for one adult keyhole cichlid is 8.92 units; this is a planning heuristic, not a replacement for testing nitrate.
Common mistakes
- Planning around the shop size instead of the adult size.
- Adding a schooling fish in a group smaller than its social minimum.
- Ignoring the tank's length, floor area or lid because the gallon number looks adequate.
- Adding fish before the aquarium is cycled and ammonia and nitrite are consistently zero.
Care ranges are conservative summaries of commonly cited husbandry references. Individual fish, strains and local water can differ; monitor the aquarium and adjust the plan gradually.
Photo source: Bartosz Senderek · CC BY-SA 2.5. The local copy is resized for page performance.