Can Green Terror and Peacock Eel Live Together?

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

Keeping Green Terror and Peacock Eel together is possible but requires caution due to differing aggression levels and potential behavioral clashes. Provide a spacious tank of at least 200 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Green Terror

Andinoacara rivulatus

Peacock Eel

Macrognathus siamensis

🐠Family Group
Green Terror
Cichlids - South American
Peacock Eel
Oddballs
Temperament
Green Terror
Aggressive (8/10)
Peacock Eel
Peaceful (2/10)
Temperature
✓ Compatible
Green Terror
20–28°C
Peacock Eel
23–28°C
pH Range
✓ Compatible
Green Terror
6.5–8
Peacock Eel
6.5–8
Hardness (dGH)
✓ Compatible
Green Terror
5–20
Peacock Eel
5–15
Water Type
✓ Compatible
Green Terror
Freshwater Only
Peacock Eel
Freshwater Only
Flow Preference
✓ Compatible
Green Terror
Moderate
Peacock Eel
Low
Min Tank Volume
Combined: 200 L
Green Terror
200 L
Peacock Eel
150 L
Swimming Level
Shared: 1 zone
Green Terror
MiddleBottom
Peacock Eel
Bottom
🏷️Behavior Tags
Green Terror
Generally AggressiveAggressive to same species/look-alikesTerritorial (Defends specific area)Piscivore (Eats small/nano fish)Digger (Disturbs Substrate)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 Green Terror 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.

Green Terror
Peacock Eel
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Behaviour & Temperament

Green Terror is a semi-aggressive species (8/10), while Peacock Eel is peaceful (2/10). This notable difference means Green Terror may occasionally assert dominance over Peacock Eel.

Large aggression gap (6 points) between Green Terror and Peacock Eel increases stress risk for the more peaceful fish.

Green Terror 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 fish may bully and stress shy, slow-moving species.

Worth noting: Peacock Eel is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Peacock Eel is a known jumper, so a tight-fitting lid is essential.

To improve the chances of a peaceful coexistence in this community tank: Provide a significantly larger tank (at least 50% more volume than the minimum) to allow both Green Terror and Peacock Eel to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations. A larger aquarium with ample hiding spots can help diffuse aggression and give the less dominant fish space to retreat.

Water Parameters

The safe temperature window for both species falls between 23°C and 28°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 and 8. 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 Green Terror and Peacock Eel together, plan for an aquarium of at least 200 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: Sand (Sifters), Driftwood (Digestion/Hiding), Smooth Gravel (Sensitive Barbels), Plants - Densely covered. Meeting these requirements will help both species thrive.

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

Both species do well with moderate (standard) water movement, so a standard filtration setup rated for the tank volume should suffice.

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. Green Terror 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 Green Terror and Peacock Eel.

Show 5 more tank sizes

Frequently Asked Questions

Can Green Terror and Peacock Eel live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 200 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Green Terror and Peacock Eel need?

A minimum of 200 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 Green Terror and Peacock Eel together?

Keep the aquarium between 23°C and 28°C. A target of around 25.5°C sits comfortably within both species' preferred ranges.

Are Green Terror or Peacock Eel aggressive?

Green Terror is semi-aggressive (8/10) and Peacock Eel is peaceful (2/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Green Terror and Peacock Eel need?

Both species overlap in the 6.5–8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

How do I manage Green Terror's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Green Terror 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 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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