Can Fire Eel and Masked Julie (Julidochromis) Live Together?

Reviewed by Guidarium Editorial DeskUpdated April 28, 2026
Not Recommended

Fire Eel and Masked Julie (Julidochromis) are not recommended as tank mates due to conflicting pH requirements. 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

Masked Julie (Julidochromis)

Julidochromis transcriptus

🐠Family Group
Fire Eel
Oddballs
Masked Julie (Julidochromis)
Cichlids - African
Temperament
Fire Eel
Mostly Peaceful (4/10)
Masked Julie (Julidochromis)
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Fire Eel
24–28°C
Masked Julie (Julidochromis)
23–27°C
pH Range
✗ No overlap
Fire Eel
6–7.5
Masked Julie (Julidochromis)
8–9
Hardness (dGH)
✓ Compatible
Fire Eel
5–15
Masked Julie (Julidochromis)
10–20
Water Type
✓ Compatible
Fire Eel
Freshwater Only
Masked Julie (Julidochromis)
Freshwater Only
Flow Preference
✓ Compatible
Fire Eel
Moderate
Masked Julie (Julidochromis)
Moderate
Min Tank Volume
Combined: 680 L
Fire Eel
680 L
Masked Julie (Julidochromis)
60 L
Swimming Level
Shared: 1 zone
Fire Eel
Bottom
Masked Julie (Julidochromis)
BottomMiddle
🏷️Behavior Tags
Fire Eel
Piscivore (Eats small/nano fish)Shrimp EaterDigger (Disturbs Substrate)Jumper (Lid Required)NocturnalShy / Slow Moving (Easily Stressed)
Masked Julie (Julidochromis)
Territorial (Defends specific area)Aggressive to same species/look-alikesFry PredatorShy / Slow Moving (Easily Stressed)
Stocking calculator

Can your tank handle Fire Eel and Masked Julie (Julidochromis)?

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
Masked Julie (Julidochromis)
Test both in my tank

Behaviour & Temperament

Fire Eel is a generally mild-mannered species (4/10), while Masked Julie (Julidochromis) is moderately assertive (6/10). This modest difference means Masked Julie (Julidochromis) may occasionally assert dominance over Fire Eel.

Fire Eel and Masked Julie (Julidochromis) 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.

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 27°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

The pH requirements of Fire Eel (6–7.5) and Masked Julie (Julidochromis) (8–9) do not overlap, making it impossible to satisfy both species simultaneously.

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

Tank Setup

To house Fire Eel and Masked Julie (Julidochromis) 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). 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 Masked Julie (Julidochromis) 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 Masked Julie (Julidochromis).

Frequently Asked Questions

Can Fire Eel and Masked Julie (Julidochromis) 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 Masked Julie (Julidochromis) 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 Masked Julie (Julidochromis) together?

Keep the aquarium between 24°C and 27°C. A target of around 25.5°C sits comfortably within both species' preferred ranges.

Are Fire Eel or Masked Julie (Julidochromis) aggressive?

Fire Eel is generally mild-mannered (4/10) and Masked Julie (Julidochromis) is moderately assertive (6/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Fire Eel and Masked Julie (Julidochromis) need?

Their pH requirements do not overlap. Fire Eel prefers 6–7.5, while Masked Julie (Julidochromis) needs 8–9. This makes them incompatible in the same water chemistry.

How do I manage Masked Julie (Julidochromis)'s territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Masked Julie (Julidochromis) 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
April 28, 2026
Last updated
April 28, 2026
Issues or corrections?
Contact the editorial team

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