Quick Answer
The Peacock Eel is a intermediate-level freshwater fish needing at least a 35-gallon tank, 73-82°F water, and pH 6.5-7.5. Peacock Eels require consistent water quality and some experience to keep successfully.
Peacock Eel Overview
The Peacock Eel (Macrognathus siamensis) is a rewarding species suited to aquarists with some experience, native to Southeast Asia. As a freshwater carnivore, this species has earned its place as a staple in community tanks, species-only setups, and planted aquariums worldwide. The Peacock Eel is a peaceful species that generally coexists well with other non-aggressive fish. With proper care and appropriate water conditions, Peacock Eels can live for several years and become a rewarding centerpiece — or supporting cast — of your aquarium.
According to FishBase's species profile, the Macrognathus siamensis is widely distributed across Southeast Asia and has been selectively bred in captivity for decades, resulting in a robust trade fish that typically adapts well to aquarium conditions. That said, replicating natural water parameters as closely as possible always produces the healthiest fish.
Tank Requirements
The Peacock Eel requires a 35-gallon tank as a minimum — larger is always better. Crowding this species into too-small quarters leads to stress, aggression, and disease — the most common cause of failure with this fish. Budget for a canister filter with adequate flow — target 4–6× tank volume per hour to keep the water clean and well-oxygenated.
- Minimum Tank Size: 35 gallons
- Temperature: 73-82°F (ideal: ~77°F)
- pH: 6.5-7.5
- Filtration: A canister filter with adequate flow — target 4–6× tank volume per hour
A fine to medium-grain substrate is appropriate for most specimens, with some species preferring sand or smooth gravel. Once your tank is fully cycled, perform 20–30% water changes weekly to maintain stable parameters. Stability matters more than hitting exact numbers — sudden swings cause far more harm than gradual drift.
Diet & Feeding
In the wild, Peacock Eels are predators that hunt live prey. In captivity, replicate this with high-protein foods. High-quality carnivore pellets, frozen bloodworms, frozen brine shrimp, mysis shrimp, and occasional live foods are all excellent choices for this species.
Feed once or twice daily, offering only what they can consume in 2–3 minutes. Remove uneaten food promptly. Variety is key — rotate between different protein sources to prevent nutritional deficiencies.
Compatibility & Tank Mates
The Peacock Eel has a peaceful temperament and does well in community aquariums with similarly sized, non-aggressive fish.
Good tank mate options from our database include African Dwarf Frog, Black Phantom Tetra, and Bolivian Ram. Avoid housing Peacock Eels with highly aggressive species or fish that compete for the same territory.
Common Health Issues
The Peacock Eel is susceptible to disease when conditions are suboptimal, but no aquarium fish is immune to illness. Prevention through clean water and a varied diet is always better than treatment. For detailed species-specific health notes, SeriouslyFish has an excellent care sheet for the Peacock Eel.
Ich (White Spot Disease)
The most common freshwater disease — small white spots on fins and body. Raise temperature to 82–86°F and treat with API Super Ich Cure. See our full guide on treating ich.
Fin Rot
Bacterial deterioration of fin tissue, usually caused by poor water quality. Improve water changes, remove organic waste, and treat with Kanaplex or Maracyn if severe.
Velvet (Oodinium)
A parasitic infection causing a gold-dust shimmer on the body. More subtle than ich but equally dangerous. Treat with copper-based medication in a quarantine tank.
Recommended Products
Frequently Asked Questions
What size tank does a Peacock Eel need?
The Peacock Eel requires a minimum of 35 gallons. Smaller tanks cause stress, reduce lifespan, and increase disease susceptibility. If you can afford a larger tank, always go bigger — fish generally thrive with extra space.
What do Peacock Eels eat?
The Peacock Eel is a carnivore. Feed high-protein foods: frozen bloodworms, mysis shrimp, carnivore pellets, and occasional live foods. Feed once or twice daily, only what they can eat in 2–3 minutes.
What water temperature and pH does the Peacock Eel need?
Maintain water temperature between 73-82°F and pH between 6.5-7.5. Use a reliable aquarium thermometer and test your water weekly. Stability is more important than hitting exact numbers — sudden parameter swings are more dangerous than gradual drift.
What fish can live with a Peacock Eel?
The Peacock Eel can coexist with African Dwarf Frog, Black Phantom Tetra, Bolivian Ram, among others with similar temperament and water requirements. Avoid pairing with aggressive fin-nippers or much larger predators.
Is the Peacock Eel suitable for intermediate aquarists?
Yes — the Peacock Eel is a good step up for aquarists moving beyond beginner species. It requires more consistent water quality and some knowledge of the nitrogen cycle, but rewards careful keeping with impressive behavior and appearance.
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