Can Festivum and Fire Eel Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 4, 2026
Ideal Tank Mates

Yes, Festivum and Fire Eel are ideal tank mates. Both species share compatible water parameters and peaceful temperaments, making them well-suited for a community aquarium. They occupy different areas of the water column, which reduces competition for space. A minimum tank size of 680 litres is recommended.


At a Glance

Festivum

Mesonauta festivus

Fire Eel

Mastacembelus erythrotaenia

🐠Family Group
Festivum
Cichlids - South American
Fire Eel
Oddballs
Temperament
Festivum
Mostly Peaceful (4/10)
Fire Eel
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Festivum
24–28°C
Fire Eel
24–28°C
pH Range
✓ Compatible
Festivum
5.5–7.2
Fire Eel
6–7.5
Hardness (dGH)
✓ Compatible
Festivum
2–12
Fire Eel
5–15
Water Type
✓ Compatible
Festivum
Freshwater Only
Fire Eel
Freshwater Only
Flow Preference
✓ Compatible
Festivum
Low
Fire Eel
Moderate
Min Tank Volume
Combined: 680 L
Festivum
150 L
Fire Eel
680 L
Swimming Level
✓ Different zones
Festivum
TopMiddle
Fire Eel
Bottom
🏷️Behavior Tags
Festivum
Plant DestroyerJumper (Lid Required)Territorial (Defends specific area)
Fire Eel
Piscivore (Eats small/nano fish)Shrimp EaterDigger (Disturbs Substrate)Jumper (Lid Required)NocturnalShy / Slow Moving (Easily Stressed)
Stocking calculator

Can your tank handle Festivum and Fire 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.

Festivum
Fire Eel
Test both in my tank

Behaviour & Temperament

Both Festivum and Fire Eel are generally mild-mannered species with an aggression score of 4/10. Their matching temperaments mean neither fish is likely to dominate the other in a shared aquarium.

In terms of spatial distribution, Festivum prefers the Top (Surface) and Middle (Open Water) zones, whereas Fire 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.

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

For general hardness, the shared comfort zone is 5–12 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Festivum and Fire 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.

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: Driftwood (Digestion/Hiding), Plants - Floating, Sand (Sifters), Smooth Gravel (Sensitive Barbels). 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

Festivum and Fire Eel 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 Festivum and Fire Eel.

Frequently Asked Questions

Can Festivum and Fire Eel live together?

Yes. Festivum and Fire Eel are considered ideal tank mates. Their water parameters, temperaments, and behaviour profiles are well matched for a community aquarium.

What size tank do Festivum and Fire 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 Festivum and Fire 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 Festivum or Fire Eel aggressive?

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

What pH do Festivum and Fire Eel need?

Both species overlap in the 6–7.2 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

How do I manage Festivum's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Festivum space to claim a territory without encroaching on the other fish's area. Adding décor that divides the tank into distinct zones works especially well.

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.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
May 4, 2026
Last updated
May 4, 2026
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