Can Ajamaru Rainbowfish and Clown Killifish Live Together?
Ajamaru Rainbowfish and Clown Killifish are not recommended as tank mates due to conflicting pH requirements. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.
At a Glance
Can your tank handle Ajamaru Rainbowfish and Clown Killifish?
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.
Behaviour & Temperament
Both Ajamaru Rainbowfish and Clown Killifish are peaceful species with an aggression score of 2/10. Their matching temperaments mean neither fish is likely to dominate the other in a shared aquarium.
Ajamaru Rainbowfish and Clown Killifish both frequent the Top (Surface) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.
Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion.
Worth noting: Ajamaru Rainbowfish is a known jumper, so a tight-fitting lid is essential.
Water Parameters
The safe temperature window for both species falls between 24°C and 27°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.
The pH requirements of Ajamaru Rainbowfish (7.2–8.5) and Clown Killifish (5–7) do not overlap, making it impossible to satisfy both species simultaneously.
For general hardness, the shared comfort zone is 8–8 dGH. Regular testing will ensure conditions stay within this range.
Tank Setup
To house Ajamaru Rainbowfish and Clown Killifish together, plan for an aquarium of at least 150 litres with a minimum length of 90 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: Plants - Densely covered, Plants - Floating, Leaf Litter/Blackwater. Meeting these requirements will help both species thrive.
Both species do well with moderate (standard) water movement, so a standard filtration setup rated for the tank volume should suffice.
Why This Pairing Usually Fails in Practice
Ajamaru Rainbowfish and Clown Killifish are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.
Suitable Tank Sizes
Standard aquarium sizes large enough for both Ajamaru Rainbowfish and Clown Killifish.
40 Gallon Breeder
55 Gallon Standard
60 Gallon Breeder
75 Gallon Standard
90 Gallon Standard
125 Gallon Standard
Show 9 more tank sizes
Frequently Asked Questions
Can Ajamaru Rainbowfish and Clown Killifish live together?
No. This combination is not recommended. Key incompatibilities — such as critical behavioural conflicts — make cohabitation unsafe.
What size tank do Ajamaru Rainbowfish and Clown Killifish need?
A minimum of 150 litres (tank length at least 90 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 Ajamaru Rainbowfish and Clown Killifish together?
Keep the aquarium between 24°C and 27°C. A target of around 25.5°C sits comfortably within both species' preferred ranges.
Are Ajamaru Rainbowfish or Clown Killifish aggressive?
Ajamaru Rainbowfish is peaceful (2/10) and Clown Killifish is peaceful (2/10). Their similar temperaments generally lead to a peaceful coexistence.
What pH do Ajamaru Rainbowfish and Clown Killifish need?
Their pH requirements do not overlap. Ajamaru Rainbowfish prefers 7.2–8.5, while Clown Killifish needs 5–7. This makes them incompatible in the same water chemistry.
Shared setup supplies
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Guidarium Editorial Desk
Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.
- Last reviewed
- May 2, 2026
- Last updated
- May 2, 2026
- Issues or corrections?
- Contact the editorial team
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