King Feathertail pair

Feather-tailed monarchs of alkaline waters—two tiny tyrants, always on guard.

King Feathertail pair: stunning aggressive fish for high pH aquariums. 5-6 cm. Ideal for experienced keepers seeking a challenging species.

• Water Conditions: The King Feathertail is a fish that thrives in high pH water, typically between 7.5 and 8.5. They prefer hard water with a general hardness (dGH) of 10–20 and a carbonate hardness (dKH) of 6–12. Temperature should be maintained between 24–28°C (75–82°F) with minimal fluctuation. A stable pH is more important than a specific number; avoid swings by using a reliable heater, regular testing, and avoiding overstocking. A tank of at least 20 gallons (75 litres) is recommended for a pair, as they can be territorial, especially during breeding. Provide gentle to moderate water flow; strong currents can stress them. Excellent filtration is mandatory—a canister filter or a hang-on-back with biological media is ideal. Perform 20–30% water changes weekly, using a gravel vacuum to remove debris. Always dechlorinate water and match temperature. These fish are sensitive to poor water quality and copper-based medications, which are toxic. Ensure the tank is fully cycled before adding them, and quarantine new arrivals for at least two weeks.
• Suitable Tank Mates: Due to their aggressive temperament, King Feathertails are best kept in a species-only aquarium. If you must add tank mates, choose robust, fast-swimming fish that occupy different areas of the tank and can tolerate high pH. Suitable options include large tetras (e.g., Congo tetras), barbs (e.g., tiger barbs), and bottom-dwelling catfish like Synodontis species. Avoid slow-moving, long-finned fish such as guppies, bettas, angelfish, and fancy goldfish—they will be nipped and stressed. Also avoid small shrimp, snails, and tiny rasboras, which may be eaten. If keeping a community, provide plenty of hiding spots (caves, driftwood, dense plants) and break lines of sight with decor. Monitor closely for aggression; if bullying occurs, separate immediately. A pair may become more aggressive during spawning, so a separate breeding tank is wise. Always quarantine new additions to prevent disease introduction. Remember that every fish has a unique personality; some King Feathertails may tolerate more than others, but caution is key.
• Feeding Habits: King Feathertails are omnivorous with hearty appetites and are aggressive eaters. They will readily accept a variety of foods, so offering a balanced diet is essential for their health and colouration. Use a high-quality staple flake or pellet food as the base, supplemented with frozen or live foods such as bloodworms, brine shrimp, daphnia, and chopped earthworms. This variety ensures they receive essential proteins, vitamins, and fibre. Feed small amounts two to three times daily, only what they can consume in 2–3 minutes. Overfeeding can lead to obesity, constipation, and water quality issues, so monitor their intake. Because they are aggressive at feeding time, ensure all tank mates get their share by distributing food across the tank or using a pipette to target specific areas. If conditioning for breeding, offer richer foods like live blackworms. Remove any uneaten food immediately to prevent ammonia spikes. Fasting one day a week can help maintain digestive health. Observe their body shape—a slightly rounded belly is healthy, but a sunken one indicates underfeeding.
• Care Requirements: Caring for King Feathertails requires dedication and attention to detail. Set up a well-maintained tank with a sandy substrate, as they may sift through it. Provide plenty of hiding places using caves, driftwood, and plants (real or artificial). Live plants like Anubias, Java fern, and Vallisneria work well in high pH. A tight-fitting lid is essential—they are known jumpers. Perform regular water changes and monitor parameters weekly. Due to their aggressive nature, watch for fin nipping, bullying, and stress. If you notice damaged fins, treat with a mild antibacterial or Melafix, and address the cause. They are livebearers, and if a pair breeds, the female can drop 20–50 fry. Provide dense floating plants for fry to hide, or move the female to a separate breeding tank. Breeding can increase aggression, so plan accordingly. Acclimate new fish slowly using the drip method to avoid shock. Handle with care, as they can be skittish. A varied diet and stable environment promote a lifespan of 3–5 years. Regular health checks, including observing gill movement and body condition, are advised. Keep a spare tank ready for isolation if needed.