Can Black Kuhli Loach and Keyhole Cichlid Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 1, 2026
Ideal Tank Mates

Yes, Black Kuhli Loach and Keyhole Cichlid are ideal tank mates. Both species share compatible water parameters and peaceful temperaments, making them well-suited for a community aquarium. A minimum tank size of 110 litres is recommended.


At a Glance

Black Kuhli Loach

Pangio oblonga

Keyhole Cichlid

Cleithracara maronii

🐠Family Group
Black Kuhli Loach
Loaches
Keyhole Cichlid
Cichlids - South American
Temperament
Black Kuhli Loach
Peaceful (1/10)
Keyhole Cichlid
Peaceful (2/10)
Temperature
✓ Compatible
Black Kuhli Loach
24–28°C
Keyhole Cichlid
22–28°C
pH Range
✓ Compatible
Black Kuhli Loach
5.5–7
Keyhole Cichlid
6–7.5
Hardness (dGH)
✓ Compatible
Black Kuhli Loach
2–10
Keyhole Cichlid
2–15
Water Type
✓ Compatible
Black Kuhli Loach
Freshwater Only
Keyhole Cichlid
Freshwater Only
Flow Preference
✓ Compatible
Black Kuhli Loach
Low
Keyhole Cichlid
Low
Min Tank Volume
Combined: 110 L
Black Kuhli Loach
60 L
Keyhole Cichlid
110 L
Swimming Level
Shared: 1 zone
Black Kuhli Loach
Bottom
Keyhole Cichlid
MiddleBottom
🏷️Behavior Tags
Black Kuhli Loach
NocturnalShy / Slow Moving (Easily Stressed)Digger (Disturbs Substrate)
Keyhole Cichlid
Shy / Slow Moving (Easily Stressed)Fry Predator
Stocking calculator

Can your tank handle Black Kuhli Loach and Keyhole Cichlid?

Compatibility is only part of the answer. Test both fish with your real tank size, current stock, and maintenance needs to see if you have enough space and a safe stocking level before you add them.

Black Kuhli Loach
Keyhole Cichlid
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Behaviour & Temperament

Black Kuhli Loach is a peaceful species (1/10), while Keyhole Cichlid is peaceful (2/10). This modest difference means Keyhole Cichlid may occasionally assert dominance over Black Kuhli Loach.

Black Kuhli Loach and Keyhole Cichlid both frequent the Bottom (Substrate) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

Worth noting: Black Kuhli Loach is nocturnal and will be most active after lights-out, naturally reducing daytime encounters.

Water Parameters

The safe temperature window for both species falls between 24°C and 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

Both fish can tolerate a pH between 6 and 7. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 2–10 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Black Kuhli Loach and Keyhole Cichlid together, plan for an aquarium of at least 110 litres with a minimum length of 80 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

Specific environmental needs for this combination include: Sand (Sifters), Leaf Litter/Blackwater, Smooth Gravel (Sensitive Barbels), Plants - Densely covered, Driftwood (Digestion/Hiding). Meeting these requirements will help both species thrive.

Both species do well with low (still water) water movement, so a standard filtration setup rated for the tank volume should suffice.

Why This Pairing Works in Practice

Black Kuhli Loach and Keyhole Cichlid work best when the tank gives each fish enough room to use its preferred level of the aquarium and enough cover to avoid constant visual contact. The score matters, but the real-world success usually comes from matching their pace, keeping water stable, and resisting the urge to crowd the tank just because the pair looks safe on paper.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Black Kuhli Loach and Keyhole Cichlid.

Show 12 more tank sizes

Frequently Asked Questions

Can Black Kuhli Loach and Keyhole Cichlid live together?

Yes. Black Kuhli Loach and Keyhole Cichlid are considered ideal tank mates. Their water parameters, temperaments, and behaviour profiles are well matched for a community aquarium.

What size tank do Black Kuhli Loach and Keyhole Cichlid need?

A minimum of 110 litres (tank length at least 80 cm) is recommended. This provides enough space for both species to establish their own areas and reduces the likelihood of territorial disputes.

What water temperature is best for Black Kuhli Loach and Keyhole Cichlid together?

Keep the aquarium between 24°C and 28°C. A target of around 26.0°C sits comfortably within both species' preferred ranges.

Are Black Kuhli Loach or Keyhole Cichlid aggressive?

Black Kuhli Loach is peaceful (1/10) and Keyhole Cichlid is peaceful (2/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Black Kuhli Loach and Keyhole Cichlid need?

Both species overlap in the 6–7 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Does Black Kuhli Loach being nocturnal affect compatibility?

Black Kuhli Loach is most active after lights-out, which naturally reduces daytime encounters with its tank mate. This can actually be beneficial, as both fish get undisturbed time to feed and explore. Just ensure food reaches Black Kuhli Loach during evening hours.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 1, 2026
Last updated
May 1, 2026
Issues or corrections?
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