Can Australian Smelt and Peacock Eel Live Together?

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

Keeping Australian Smelt and Peacock Eel 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

Australian Smelt

Retropinna semoni

Peacock Eel

Macrognathus siamensis

🐠Family Group
Australian Smelt
Other
Peacock Eel
Oddballs
Temperament
Australian Smelt
Peaceful (1/10)
Peacock Eel
Peaceful (2/10)
Temperature
✓ Compatible
Australian Smelt
15–24°C
Peacock Eel
23–28°C
pH Range
✓ Compatible
Australian Smelt
6.5–8
Peacock Eel
6.5–8
Hardness (dGH)
✓ Compatible
Australian Smelt
5–20
Peacock Eel
5–15
Water Type
✓ Compatible
Australian Smelt
Brackish Tolerant
Peacock Eel
Freshwater Only
Flow Preference
✓ Compatible
Australian Smelt
Moderate
Peacock Eel
Low
Min Tank Volume
Combined: 150 L
Australian Smelt
75 L
Peacock Eel
150 L
Swimming Level
✓ Different zones
Australian Smelt
TopMiddle
Peacock Eel
Bottom
🏷️Behavior Tags
Australian Smelt
Hyperactive / Fast SwimmerShy / Slow Moving (Easily Stressed)Fry PredatorJumper (Lid Required)
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 Australian Smelt 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.

Australian Smelt
Peacock Eel
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Behaviour & Temperament

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

In terms of spatial distribution, Australian Smelt prefers the Top (Surface) and Middle (Open Water) zones, whereas Peacock Eel occupies the Bottom (Substrate) 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. Aggressive eaters may outcompete shy fish for food, leading to malnutrition.

Worth noting: Peacock Eel is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Australian Smelt 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 23°C and 24°C. Aim for the midpoint of this range (around 23.5°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 Australian Smelt and Peacock Eel 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: Plants - lighly covered, Smooth Gravel (Sensitive Barbels), Sand (Sifters), 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 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. Australian Smelt 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 Australian Smelt and Peacock Eel.

Show 9 more tank sizes

Diet & Feeding

Feeding time deserves special attention with this pairing. Peacock Eel is an aggressive eater that may prevent Australian Smelt from getting enough food.

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

Frequently Asked Questions

Can Australian Smelt and Peacock Eel 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 Australian Smelt and Peacock Eel 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 Australian Smelt and Peacock Eel together?

Keep the aquarium between 23°C and 24°C. A target of around 23.5°C sits comfortably within both species' preferred ranges.

Are Australian Smelt or Peacock Eel aggressive?

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

What pH do Australian Smelt 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.

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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