Can Filament Barb and Peacock Eel Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 7, 2026
Possible with Caution

Keeping Filament Barb and Peacock Eel together is possible but requires caution due to potential behavioral clashes and mismatched flow preferences. Provide a spacious tank of at least 240 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Filament Barb

Dawkinsia filamentosa

Peacock Eel

Macrognathus siamensis

🐠Family Group
Filament Barb
Cyprinids
Peacock Eel
Oddballs
Temperament
Filament Barb
Mostly Peaceful (4/10)
Peacock Eel
Peaceful (2/10)
Temperature
✓ Compatible
Filament Barb
20–26°C
Peacock Eel
23–28°C
pH Range
✓ Compatible
Filament Barb
6–7.5
Peacock Eel
6.5–8
Hardness (dGH)
✓ Compatible
Filament Barb
4–15
Peacock Eel
5–15
Water Type
✓ Compatible
Filament Barb
Freshwater Only
Peacock Eel
Freshwater Only
Flow Preference
✗ No overlap
Filament Barb
High
Peacock Eel
Low
Min Tank Volume
Combined: 240 L
Filament Barb
240 L
Peacock Eel
150 L
Swimming Level
Shared: 1 zone
Filament Barb
MiddleBottom
Peacock Eel
Bottom
🏷️Behavior Tags
Filament Barb
Hyperactive / Fast SwimmerFin NipperJumper (Lid Required)Plant Destroyer
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 Filament Barb 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.

Filament Barb
Peacock Eel
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Behaviour & Temperament

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

Filament Barb 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: 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, Filament Barb 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. Keep fin nippers in larger groups to distribute nipping behaviour among conspecifics rather than tank mates.

Water Parameters

The safe temperature window for both species falls between 23°C and 26°C. Aim for the midpoint of this range (around 24.5°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 Filament Barb and Peacock Eel together, plan for an aquarium of at least 240 litres with a minimum length of 120 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: Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding), Sand (Sifters), Plants - Densely covered. Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Filament Barb is a plant destroyer, which conflicts with Peacock Eel's requirement for live plants. Compromise where possible or prioritise the more critical need.

Filament Barb prefers High (River/Stream) flow while Peacock Eel needs Low (Still Water) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.

Why This Pairing Needs Extra Planning in Practice

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Filament Barb and Peacock Eel need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Filament Barb and Peacock Eel.

Show 3 more tank sizes

Frequently Asked Questions

Can Filament Barb and Peacock Eel live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 240 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Filament Barb and Peacock Eel need?

A minimum of 240 litres (tank length at least 120 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 Filament Barb and Peacock Eel together?

Keep the aquarium between 23°C and 26°C. A target of around 24.5°C sits comfortably within both species' preferred ranges.

Are Filament Barb or Peacock Eel aggressive?

Filament Barb 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 Filament Barb 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.

Will Filament Barb nip Peacock Eel's fins?

Filament Barb is a known fin nipper. If Peacock Eel has long or flowing fins, there is a real risk of fin damage. Keeping Filament Barb in a larger group can help redirect nipping behaviour toward conspecifics.

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.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
May 7, 2026
Last updated
May 7, 2026
Issues or corrections?
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