Can Celebes Rainbowfish and Clown Knifefish Live Together?

🟡Possible with Caution

Keeping Celebes Rainbowfish and Clown Knifefish together is possible but requires caution due to differing aggression levels and potential behavioral clashes. Provide a spacious tank of at least 900 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Celebes Rainbowfish

Marosatherina ladigesi

Clown Knifefish

Chitala ornata

🐠Family Group
Celebes Rainbowfish
Rainbowfish
Clown Knifefish
Oddballs
Temperament
Celebes Rainbowfish
Peaceful (2/10)
Clown Knifefish
Aggressive (7/10)
Temperature
✓ Compatible
Celebes Rainbowfish
22–28°C
Clown Knifefish
24–28°C
pH Range
✓ Compatible
Celebes Rainbowfish
7–8.5
Clown Knifefish
6–7.5
Hardness (dGH)
✓ Compatible
Celebes Rainbowfish
10–25
Clown Knifefish
5–15
Water Type
✓ Compatible
Celebes Rainbowfish
Brackish Tolerant
Clown Knifefish
Freshwater Only
Flow Preference
✓ Compatible
Celebes Rainbowfish
Moderate
Clown Knifefish
Moderate
Min Tank Volume
Combined: 900 L
Celebes Rainbowfish
75 L
Clown Knifefish
750 L
Swimming Level
Shared: 1 zone
Celebes Rainbowfish
TopMiddle
Clown Knifefish
MiddleBottom
🏷️Behavior Tags
Celebes Rainbowfish
Hyperactive / Fast SwimmerJumper (Lid Required)Fry Predator
Clown Knifefish
Piscivore (Eats small/nano fish)NocturnalJumper (Lid Required)Aggressive to same species/look-alikesShy / Slow Moving (Easily Stressed)

Behaviour & Temperament

Celebes Rainbowfish is a peaceful species (2/10), while Clown Knifefish is semi-aggressive (7/10). This notable difference means Clown Knifefish may occasionally assert dominance over Celebes Rainbowfish.

Celebes Rainbowfish and Clown Knifefish both frequent the Middle (Open Water) 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: Clown Knifefish is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Celebes Rainbowfish is a known jumper, so a tight-fitting lid is essential.

To improve the chances of a peaceful coexistence in this community tank: A larger aquarium with ample hiding spots can help diffuse aggression and give the less dominant fish space to retreat.

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 7 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 10–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Celebes Rainbowfish and Clown Knifefish together, plan for an aquarium of at least 900 litres with a minimum length of 180 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Plants - lighly covered, Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding), Plants - Densely covered. 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.

Frequently Asked Questions

Can Celebes Rainbowfish and Clown Knifefish live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 900 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Celebes Rainbowfish and Clown Knifefish need?

A minimum of 900 litres (tank length at least 180 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 Celebes Rainbowfish and Clown Knifefish 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 Celebes Rainbowfish or Clown Knifefish aggressive?

Celebes Rainbowfish is peaceful (2/10) and Clown Knifefish is semi-aggressive (7/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Celebes Rainbowfish and Clown Knifefish need?

Both species overlap in the 7–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Does Clown Knifefish being nocturnal affect compatibility?

Clown Knifefish 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 Clown Knifefish during evening hours.


Related Comparisons

Celebes Rainbowfish & Boeseman's Rainbowfish

·

🟢Ideal Tank Mates
Celebes Rainbowfish: PeacefulBoeseman's Rainbowfish: Peaceful

Celebes Rainbowfish & Dwarf Neon Rainbowfish (Praecox)

·

🟢Ideal Tank Mates
Celebes Rainbowfish: PeacefulDwarf Neon Rainbowfish (Praecox): Peaceful

Celebes Rainbowfish & Forktail Blue-eye

·

🟢Ideal Tank Mates
Celebes Rainbowfish: PeacefulForktail Blue-eye: Peaceful

Celebes Rainbowfish & Gertrude's Spotted Blue-eye

·

🟢Ideal Tank Mates
Celebes Rainbowfish: PeacefulGertrude's Spotted Blue-eye: Peaceful

Celebes Rainbowfish & Red Rainbowfish

·

🟢Ideal Tank Mates
Celebes Rainbowfish: PeacefulRed Rainbowfish: Peaceful

Celebes Rainbowfish & Turquoise Rainbowfish

·

🟢Ideal Tank Mates
Celebes Rainbowfish: PeacefulTurquoise Rainbowfish: Peaceful

Clown Knifefish & Black Ghost Knifefish

·

🟡Possible with Caution
Clown Knifefish: PeacefulBlack Ghost Knifefish: Peaceful

Clown Knifefish & Indonesian Datnoid (Tiger Fish)

·

🟡Possible with Caution
Clown Knifefish: PeacefulIndonesian Datnoid (Tiger Fish): Peaceful

Clown Knifefish & Tire Track Eel

·

🟡Possible with Caution
Clown Knifefish: PeacefulTire Track Eel: Peaceful

Clown Knifefish & Motoro Stingray

·

🟡Possible with Caution
Clown Knifefish: PeacefulMotoro Stingray: Peaceful

Clown Knifefish & Peter's Elephantnose Fish

·

🟡Possible with Caution
Clown Knifefish: PeacefulPeter's Elephantnose Fish: Peaceful

Clown Knifefish & Senegal Bichir

·

🟡Possible with Caution
Clown Knifefish: PeacefulSenegal Bichir: Peaceful