Keyhole cichlid care

Cleithracara maronii · Lower Orinoco basin in Venezuela and the Guianas

Keyhole cichlid (Cleithracara maronii) — Photo: D.W., Public domain, via Wikimedia Commons

Keyhole cichlids are shy, peaceful cichlids named for the dark keyhole-shaped spot on their side.

Tank size: 30 US gal or larger
Temperature: 72 to 80 °F (22 to 27 °C)
Group size: Alone or in a pair
Temperament: Peaceful
Adult size: 4 in
pH: 6 to 7.5
Hardness (GH): 2 to 12 dGH
Lifespan: 8 to 10 years
Diet: Omnivore
Care level: Easy

In a 30 gallon

36¼ × 12⅝ × 16¾ in outside

Drawn to scale: one keyhole cichlid at adult size (4 in) in the smallest listed tank that suits them. Choose your tank on the home page to see them in it.

How to keep keyhole cichlids

Keyhole cichlids are shy, peaceful cichlids named for the dark keyhole-shaped spot on their side. A pair suits a 30 gallon or larger planted tank at 72 to 80 °F with hiding places and calm tankmates; aggressive fish keep them hidden.

Diet: Omnivore: small cichlid pellets, flakes, frozen foods. Fish food types compared · how often to feed.

Where they swim: Middle of the tank.

Keyhole cichlid tank mates

Share the temperature and water, and neither side eats, nips or bullies the other. Check the full group in the stocking checker.

Kribensis

4 in · 29+ gal · 75–80 °F

Kuhli loach

4 in · 20+ gal · 75–82 °F

Zebra loach

4 in · 29+ gal · 73–79 °F

Golden wonder killifish

4 in · 20+ gal · 72–79 °F

Banded gourami

4 in · 30+ gal · 72–82 °F

Pearl gourami

4.5 in · 29+ gal · 77–82 °F

Dwarf gourami

3.5 in · 10+ gal · 77–82 °F

Paradise fish

3.5 in · 20+ gal · 61–79 °F

Keep apart

Discus: No shared temperature: keyhole cichlids need 72 to 80 °F, discus 82 to 88 °F.
Pea puffer: Pea puffers belong in a tank of their own.
Convict cichlid: Convict cichlids are aggressive towards peaceful fish such as keyhole cichlids.
Jewel cichlid: Jewel cichlids are aggressive towards peaceful fish such as keyhole cichlids.
Demasoni cichlid: Demasoni cichlids are aggressive towards peaceful fish such as keyhole cichlids.
Red zebra cichlid: Red zebra cichlids are aggressive towards peaceful fish such as keyhole cichlids.

What a keyhole cichlid tank needs

A tank of 30 US gallons or more (such as the 30 gallon) with a cover, and the equipment below.

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Aqueon PRO QuietFlow Power Filter 20

Rated by the maker for up to 30 US gal, which covers a 30 gallon keyhole cichlid tank without being built for a far bigger one.

Details and fit →

Aqueon QuietFlow Internal Power Filter 15–30 gal

Rated by the maker for 15–30 US gal, which covers a 30 gallon keyhole cichlid tank without being built for a far bigger one.

Details and fit →

Fluval E100

Keyhole cichlids need 72 to 80 °F; most homes run cooler, so a heater holds the temperature.

Details and fit →

API Freshwater Master Test Kit

Tests ammonia, nitrite, nitrate and pH, the readings that matter most before and after adding keyhole cichlids.

Details and fit →Check price on Amazon

Seachem Prime 100 mL

Removes chlorine and chloramine from tap water at every water change.

Details and fit →Check price on Amazon

Fluval Edge Thermometer

Shows the water temperature at a glance, so you know it stays within 72 to 80 °F.

Details and fit →Check price on Amazon

We don’t list fish food: any good brand of the foods under Diet will do. Plan the whole tank's equipment →

Common keyhole cichlid problems

With boisterous tankmates they hide and stop eating.
A school of small, calm tetras as dither fish helps them come out.

Test the water first whenever fish look unwell: see what your readings mean, then match the symptom. For disease, a vet who treats fish can diagnose it and advise treatment.

More to compare

Fish for a 30 gallon tank Angelfish tank mates Centerpiece fish Types of cichlids Easy plants for its tank

Angelfish

6 in · 29+ gal

Discus

8 in · 55+ gal

German blue ram

3 in · 20+ gal

Cockatoo dwarf cichlid

3 in · 20+ gal

Sources

Name and origin checked against Wikipedia: Cleithracara maronii. Adult size, temperature, pH, hardness, group size, lifespan and minimum tank size are common hobby guidance, not figures from that article. Ranges are the range the species tolerates; aim for the middle. Minimum tank sizes are for an adult group. Drawings are our own; photo credits follow.

Photo credits

Real photographs from Wikimedia Commons, resized and cropped to fit; each is used under the license named.

Keyhole cichlid D.W., Public domain, via Wikimedia Commons
Kribensis André Karwath aka Aka, CC BY-SA 2.5, via Wikimedia Commons
Kuhli loach Iidkk, CC BY-SA 4.0, via Wikimedia Commons
Zebra loach Lerdsuwa, CC BY-SA 3.0, via Wikimedia Commons
Golden wonder killifish Marrabbio2, CC BY-SA 3.0, via Wikimedia Commons
Banded gourami Sandipan Das, CC BY 4.0, via Wikimedia Commons
Pearl gourami h080, CC BY-SA 2.0, via Wikimedia Commons
Dwarf gourami Quatermass (English Wikipedia), Public domain, via Wikimedia Commons
Paradise fish André Karwath; edited by Muhammad, CC BY-SA 2.5, via Wikimedia Commons
Discus Patrick Farrelly, Public domain, via Wikimedia Commons
Pea puffer Beta Mahatvaraj, CC BY-SA 4.0, via Wikimedia Commons
Convict cichlid S. Olkowicz, CC BY 2.5, via Wikimedia Commons
Jewel cichlid NasserHalaweh, CC BY-SA 4.0, via Wikimedia Commons
Demasoni cichlid lee Nachtigal, CC BY 2.0, via Wikimedia Commons
Red zebra cichlid Maha Dinesh, CC BY-SA 3.0, via Wikimedia Commons
Angelfish Citron, CC BY-SA 3.0, via Wikimedia Commons
German blue ram Eric Mengel, Public domain, via Wikimedia Commons
Cockatoo dwarf cichlid William Kreijkes, CC BY-SA 3.0, via Wikimedia Commons