Can Peacock Eel and Rosy Finned Tetra Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Possible with Caution

Keeping Peacock Eel and Rosy Finned Tetra together is possible but requires caution due to potential behavioral clashes. Provide a spacious tank of at least 150 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Peacock Eel

Macrognathus siamensis

Rosy Finned Tetra

Hyphessobrycon rosaceus

🐠Family Group
Peacock Eel
Oddballs
Rosy Finned Tetra
Characins
Temperament
Peacock Eel
Peaceful (2/10)
Rosy Finned Tetra
Peaceful (1/10)
Temperature
✓ Compatible
Peacock Eel
23–28°C
Rosy Finned Tetra
24–28°C
pH Range
✓ Compatible
Peacock Eel
6.5–8
Rosy Finned Tetra
5.5–7.5
Hardness (dGH)
✓ Compatible
Peacock Eel
5–15
Rosy Finned Tetra
1–12
Water Type
✓ Compatible
Peacock Eel
Freshwater Only
Rosy Finned Tetra
Freshwater Only
Flow Preference
✓ Compatible
Peacock Eel
Low
Rosy Finned Tetra
Moderate
Min Tank Volume
Combined: 150 L
Peacock Eel
150 L
Rosy Finned Tetra
60 L
Swimming Level
✓ Different zones
Peacock Eel
Bottom
Rosy Finned Tetra
Middle
🏷️Behavior Tags
Peacock Eel
Digger (Disturbs Substrate)Jumper (Lid Required)NocturnalShy / Slow Moving (Easily Stressed)Shrimp EaterFry PredatorAggressive Eater (Starves shy fish)
Rosy Finned Tetra
Nano / Bite-sized (Predation Risk)Hyperactive / Fast Swimmer
Stocking calculator

Can your tank handle Peacock Eel and Rosy Finned 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.

Peacock Eel
Rosy Finned Tetra
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Behaviour & Temperament

Peacock Eel is a peaceful species (2/10), while Rosy Finned Tetra is peaceful (1/10). This modest difference means Peacock Eel may occasionally assert dominance over Rosy Finned Tetra.

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

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: 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: 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 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 6.5 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 5–12 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Peacock Eel and Rosy Finned Tetra together, plan for an aquarium of at least 150 litres with a minimum length of 90 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), Smooth Gravel (Sensitive Barbels), Plants - Densely covered, Leaf Litter/Blackwater. 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 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. Peacock Eel and Rosy Finned Tetra 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 Peacock Eel and Rosy Finned Tetra.

Show 9 more tank sizes

Diet & Feeding

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

Because Peacock Eel is a fast, competitive feeder, consider using sinking pellets or feeding at opposite ends of the setup to ensure Rosy Finned Tetra receives an adequate share.

Frequently Asked Questions

Can Peacock Eel and Rosy Finned Tetra live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 150 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Peacock Eel and Rosy Finned Tetra need?

A minimum of 150 litres (tank length at least 90 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 Peacock Eel and Rosy Finned Tetra 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 Peacock Eel or Rosy Finned Tetra aggressive?

Peacock Eel is peaceful (2/10) and Rosy Finned Tetra is peaceful (1/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Peacock Eel and Rosy Finned 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 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 11, 2026
Last updated
May 11, 2026
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