Can Fire Eel and Peacock Eel Live Together?

Possible with Caution

Keeping Fire Eel and Peacock Eel together is possible but requires caution due to potential behavioral clashes. Provide a spacious tank of at least 680 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Fire Eel

Mastacembelus erythrotaenia

Peacock Eel

Macrognathus siamensis

🐟Family Group
Fire Eel
Oddballs
Peacock Eel
Oddballs
Temperament
Fire Eel
Mostly Peaceful (4/10)
Peacock Eel
Peaceful (2/10)
Temperature
✓ Compatible
Fire Eel
24–28°C
Peacock Eel
23–28°C
pH Range
✓ Compatible
Fire Eel
6–7.5
Peacock Eel
6.5–8
Hardness (dGH)
✓ Compatible
Fire Eel
5–15
Peacock Eel
5–15
Water Type
✓ Compatible
Fire Eel
Freshwater Only
Peacock Eel
Freshwater Only
Flow Preference
✓ Compatible
Fire Eel
Moderate
Peacock Eel
Low
Min Tank Volume
Combined: 680 L
Fire Eel
680 L
Peacock Eel
150 L
Swimming Level
Shared: 1 zone
Fire Eel
Bottom
Peacock Eel
Bottom
🏷️Behavior Tags
Fire Eel
Piscivore (Eats small/nano fish)Shrimp EaterDigger (Disturbs Substrate)Jumper (Lid Required)NocturnalShy / Slow Moving (Easily Stressed)
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 Fire Eel 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.

Fire Eel
Peacock Eel
Test both in my tank

Behaviour & Temperament

Fire Eel is a generally mild-mannered species (4/10), while Peacock Eel is peaceful (2/10). This modest difference means Fire Eel may occasionally assert dominance over Peacock Eel.

Fire Eel and Peacock Eel 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.

Additional behavioural considerations to keep in mind: Aggressive eaters may outcompete shy fish for food, leading to malnutrition.

Worth noting: Fire Eel is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Fire Eel 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 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 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 5–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Fire Eel and Peacock Eel together, plan for an aquarium of at least 680 litres with a minimum length of 180 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: Sand (Sifters), 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.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Fire Eel and Peacock Eel.

Diet & Feeding

Feeding time deserves special attention with this pairing. Peacock Eel is an aggressive eater that may prevent Fire Eel from getting enough food.

Because Peacock Eel is a fast, competitive feeder, consider using sinking pellets or feeding at opposite ends of the setup to ensure Fire Eel receives an adequate share.

Frequently Asked Questions

Can Fire Eel and Peacock Eel live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 680 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Fire Eel and Peacock Eel need?

A minimum of 680 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 Fire Eel 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 Fire Eel or Peacock Eel aggressive?

Fire Eel is generally mild-mannered (4/10) and Peacock Eel is peaceful (2/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Fire Eel and Peacock Eel need?

Both species overlap in the 6.5–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Does Fire Eel being nocturnal affect compatibility?

Fire 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 Fire Eel during evening hours.


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