Can Ajamaru Rainbowfish and Peacock Eel Live Together?

Possible with Caution

Keeping Ajamaru Rainbowfish and Peacock Eel together is possible but requires caution due to potential behavioral clashes. Provide a spacious tank of at least 150 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Ajamaru Rainbowfish

Melanotaenia ajamaruensis

Peacock Eel

Macrognathus siamensis

🐠Family Group
Ajamaru Rainbowfish
Rainbowfish
Peacock Eel
Oddballs
Temperament
Ajamaru Rainbowfish
Peaceful (2/10)
Peacock Eel
Peaceful (2/10)
Temperature
✓ Compatible
Ajamaru Rainbowfish
24–28°C
Peacock Eel
23–28°C
pH Range
✓ Compatible
Ajamaru Rainbowfish
7.2–8.5
Peacock Eel
6.5–8
Hardness (dGH)
✓ Compatible
Ajamaru Rainbowfish
8–20
Peacock Eel
5–15
Water Type
✓ Compatible
Ajamaru Rainbowfish
Freshwater Only
Peacock Eel
Freshwater Only
Flow Preference
✓ Compatible
Ajamaru Rainbowfish
Moderate
Peacock Eel
Low
Min Tank Volume
Combined: 150 L
Ajamaru Rainbowfish
150 L
Peacock Eel
150 L
Swimming Level
✓ Different zones
Ajamaru Rainbowfish
TopMiddle
Peacock Eel
Bottom
🏷️Behavior Tags
Ajamaru Rainbowfish
Hyperactive / Fast SwimmerJumper (Lid Required)Fry Predator
Peacock Eel
Digger (Disturbs Substrate)Jumper (Lid Required)NocturnalShy / Slow Moving (Easily Stressed)Shrimp EaterFry PredatorAggressive Eater (Starves shy fish)
Stocking calculator

Can your tank handle Ajamaru Rainbowfish and Peacock Eel?

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.

Ajamaru Rainbowfish
Peacock Eel
Test both in my tank

Behaviour & Temperament

Both Ajamaru Rainbowfish and Peacock Eel 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.

In terms of spatial distribution, Ajamaru Rainbowfish prefers the Top (Surface) and Middle (Open Water) zones, whereas Peacock Eel occupies the Bottom (Substrate) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion.

Worth noting: Peacock Eel is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Ajamaru 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 7.2 and 8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 8–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Ajamaru Rainbowfish and Peacock Eel 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.

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 - Densely covered, Sand (Sifters), Smooth Gravel (Sensitive Barbels). 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.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Ajamaru Rainbowfish and Peacock Eel.

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Frequently Asked Questions

Can Ajamaru Rainbowfish and Peacock Eel live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 150 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Ajamaru Rainbowfish and Peacock Eel 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 Peacock Eel 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 Ajamaru Rainbowfish or Peacock Eel aggressive?

Ajamaru Rainbowfish is peaceful (2/10) and Peacock Eel is peaceful (2/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Ajamaru Rainbowfish and Peacock Eel need?

Both species overlap in the 7.2–8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Does Peacock Eel being nocturnal affect compatibility?

Peacock Eel 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 Peacock Eel during evening hours.


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