Quick Answer
The Redtail Catfish is a expert-level freshwater fish needing at least a 1000-gallon tank, 68-79°F water, and pH 6.0-7.5. Redtail Catfishs demand precise water conditions and are best kept by experienced aquarists.
Redtail Catfish Overview
The Redtail Catfish (Phractocephalus hemioliopterus) is a challenging but stunning species for experienced aquarists only, native to South America. As a freshwater carnivore, this species has earned its place as a staple in community tanks, species-only setups, and planted aquariums worldwide. The Redtail Catfish has unique compatibility needs that vary by individual and tank setup. With proper care and appropriate water conditions, Redtail Catfishs can live for several years and become a rewarding centerpiece — or supporting cast — of your aquarium.
According to FishBase's species profile, the Phractocephalus hemioliopterus is widely distributed across South America 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 Redtail Catfish requires a 1000-gallon or larger aquarium — this is a non-negotiable minimum. 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 high-capacity canister filter or sump system to keep the water clean and well-oxygenated.
- Minimum Tank Size: 1000 gallons
- Temperature: 68-79°F (ideal: ~73°F)
- pH: 6.0-7.5 To lower pH toward the 6.0-7.5 range, consider RO/DI water, driftwood, or Indian almond leaves. See our guide on how to lower pH in your aquarium.
- Filtration: A high-capacity canister filter or sump system
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, Redtail Catfishs 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 Redtail Catfish's compatibility depends on tank size and individual temperament. Research specific tank mate choices carefully before mixing species.
Good tank mate options from our database include Angelfish, Apistogramma, and Betta Fish. Monitor new introductions closely for signs of aggression or stress.
Common Health Issues
The Redtail Catfish 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 Redtail Catfish.
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.
Hole in the Head (HITH)
A nutritional and water-quality related disease causing pitting around the head and lateral line. Address with varied diet (vitamin-rich foods), carbon removal, and excellent water quality.
Recommended Products
Frequently Asked Questions
What size tank does a Redtail Catfish need?
The Redtail Catfish requires a minimum of 1000 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 Redtail Catfishs eat?
The Redtail Catfish 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 Redtail Catfish need?
Maintain water temperature between 68-79°F and pH between 6.0-7.5. 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 Redtail Catfish?
The Redtail Catfish can coexist with Angelfish, Apistogramma, Betta Fish, among others with similar temperament and water requirements. Avoid pairing with timid small fish that will be stressed by this species.
Is the Redtail Catfish hard to keep?
Yes — the Redtail Catfish is considered an expert-level fish requiring precise water chemistry, specialized diet, and extensive tank space. It is not recommended for beginners. Research thoroughly before purchasing, and never buy on impulse.
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