Can Fire Eel and Green Fire Tetra Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Not Recommended

Fire Eel and Green Fire Tetra are not recommended as tank mates due to piscivorous fish will prey on nano-sized tank mates.. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Fire Eel

Mastacembelus erythrotaenia

Green Fire Tetra

Aphyocharax rathbuni

🐠Family Group
Fire Eel
Oddballs
Green Fire Tetra
Characins
Temperament
Fire Eel
Mostly Peaceful (4/10)
Green Fire Tetra
Peaceful (2/10)
Temperature
✓ Compatible
Fire Eel
24–28°C
Green Fire Tetra
20–26°C
pH Range
✓ Compatible
Fire Eel
6–7.5
Green Fire Tetra
6.5–7.5
Hardness (dGH)
✓ Compatible
Fire Eel
5–15
Green Fire Tetra
2–15
Water Type
✓ Compatible
Fire Eel
Freshwater Only
Green Fire Tetra
Freshwater Only
Flow Preference
✓ Compatible
Fire Eel
Moderate
Green Fire Tetra
Moderate
Min Tank Volume
Combined: 680 L
Fire Eel
680 L
Green Fire Tetra
55 L
Swimming Level
✓ Different zones
Fire Eel
Bottom
Green Fire Tetra
MiddleTop
🏷️Behavior Tags
Fire Eel
Piscivore (Eats small/nano fish)Shrimp EaterDigger (Disturbs Substrate)Jumper (Lid Required)NocturnalShy / Slow Moving (Easily Stressed)
Green Fire Tetra
Nano / Bite-sized (Predation Risk)Hyperactive / Fast Swimmer
Stocking calculator

Can your tank handle Fire Eel and Green Fire Tetra?

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
Green Fire Tetra
Test both in my tank

Behaviour & Temperament

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

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

There is a critical concern: the Piscivore (Eats small/nano fish) behaviour of one fish directly conflicts with the Nano / Bite-sized (Predation Risk) trait of the other — piscivorous fish will prey on nano-sized tank mates..

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Shrimp eaters may also prey on very small nano fish.

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 26°C. Aim for the midpoint of this range (around 25.0°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 Green Fire Tetra 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: 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.

Why This Pairing Usually Fails in Practice

Fire Eel and Green Fire Tetra 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 Fire Eel and Green Fire Tetra.

Diet & Feeding

Feeding time deserves special attention with this pairing. Fire Eel is a known shrimp eater and may prey on small invertebrates or nano fish like Green Fire Tetra.

Frequently Asked Questions

Can Fire Eel and Green Fire Tetra live together?

No. This combination is not recommended. Key incompatibilities — such as critical behavioural conflicts — make cohabitation unsafe.

What size tank do Fire Eel and Green Fire Tetra 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 Green Fire Tetra together?

Keep the aquarium between 24°C and 26°C. A target of around 25.0°C sits comfortably within both species' preferred ranges.

Are Fire Eel or Green Fire Tetra aggressive?

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

What pH do Fire Eel and Green Fire Tetra 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.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
May 6, 2026
Last updated
May 6, 2026
Issues or corrections?
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