Betta (King Feathertail blue grizzle)

Meet the King Feathertail blue grizzle — a stunning yet aggressive aquatic gem (5-6cm) that commands high-pH water conditions and expert-level care.

• Water Conditions — The High-pH Imperative: The King Feathertail blue grizzle is not a fish for beginners navigating neutral parameters; it demands a distinctly alkaline environment. You must maintain a pH consistently between 7.8 and 8.6, ideally replicating the mineral-rich, hard-water biotopes of its natural habitat. Soft, acidic water will quickly lead to osmotic stress, faded colouration, and increased susceptibility to disease. To achieve and stabilise this elevated pH, incorporate crushed coral, aragonite, or limestone-based substrates into your filtration or hardscape. Regular water testing is non-negotiable — invest in a reliable digital pH meter and test at least twice weekly. Water hardness should sit between 12 and 20 dGH, with carbonate hardness (kH) kept above 8 dKH to buffer against dangerous pH swings. Temperature must remain stable in the upper range of 24°C to 28°C; sudden thermal drops can suppress the immune system and trigger latent infections. Filtration should be robust yet gentle — these fish appreciate well-oxygenated, moving water but dislike harsh current. Consider a high-flow canister filter paired with a spray bar to diffuse output. Perform weekly water changes of 30–40%, matching new water precisely to tank temperature and pH to avoid shocking this sensitive species. Never use pure RO water without remineralising agents; the King Feathertail simply will not tolerate instability.
• Tank Mates — Choosing Wisely with an Aggressive Nature: Temperament is the defining challenge here: the King Feathertail blue grizzle is markedly aggressive, especially when establishing territory or competing for food. It is best housed in a species-only tank, or with larger, robust, equally assertive fish capable of holding their own. Ideal companions include large cichlids of similar size, such as some Haplochromis or Aulonocara species, provided you use a spacious aquarium of at least 300 litres to allow territorial separation. Avoid anything small, slow-moving, or long-finned — the King Feathertail may nip fins relentlessly or outright bully smaller tank