Blonde koi guppy

A guppy in koi's clothing, drifting through low-pH waters.

Blonde Koi Guppies are peaceful, colourful livebearers ideal for community and nano aquariums. Hardy, low-pH tolerant and easy to keep, with striking koi patterning.

• Water Conditions: Blonde koi guppies are adaptable, hardy livebearers, but they reward stable water far more than "textbook perfect" numbers. Aim for a temperature of 22–28°C (72–82°F), with 24–26°C being ideal for long-term health and vivid colour. Their listed low-pH tolerance is genuine — these fish will settle happily in soft, slightly acidic water — although guppies originally hail from hard, alkaline streams, so they cope best within a pH range of roughly 6.8 to 8.0 rather than at extremes. If you keep them in the lower end of that scale (pH 6.5–7.0), consistency is everything: a stable pH 6.8 is far kinder than a value that swings between 6.5 and 7.6. Pair soft, acidic conditions with adequate mineral content so the fish can maintain healthy osmoregulation. A general hardness of 8–20 dGH and carbonate hardness of 4–12 dKH suits them well. Ammonia and nitrite must always read zero, and nitrate should be kept below 20 ppm with regular partial water changes. Always use a fully cycled, mature filter, match the temperature of replacement water, and dechlorinate before it touches the tank. Because these fish are small — just 3–4 cm — and produce a modest bioload, a planted 40-litre aquarium comfortably houses a small group, but never cut corners on filtration or water quality.
• Suitable Tank Mates: Peaceful by nature, blonde koi guppies are classic community fish that do best with other calm, similarly sized species. Excellent companions include other guppies, Endler's livebearers, platies, mollies, small tetras such as neons, embers and glowlights, and peaceful rasboras like harlequins and chillies. Bottom dwellers are ideal too: pygmy and panda corydoras, otocinclus, kuhli loaches, plus cherry shrimp and nerite snails. What you should avoid matters just as much. Steer clear of fin nippers such as tiger barbs, serpae tetras and black widow tetras, which will shred those long, flowing tails. Large or predatory tank mates — angelfish, bigger cichlids, oscars, and anything that sees a 3 cm fish as a snack — are unsuitable, especially if you plan to raise fry. Crayfish, freshwater crabs and large frogs are risky too. Remember that even "peaceful" fish will opportunistically eat guppy fry, so if you want babies to survive, provide dense planting or a separate breeding tank.
• Feeding Habits: Blonde koi guppies are omnivores with small mouths and fast metabolisms, so a varied, fine-grained diet keeps them thriving. Use a high-quality micro granule or finely crushed flake as the staple, offering two to three small feedings per day rather than one large meal. Rotate in live and frozen foods — baby brine shrimp, daphnia, cyclops, grindal worms and bloodworm — to boost colour, condition and breeding activity. Plant matter is important for digestion: spirulina flake, blanched spinach or courgette, and the occasional algae wafer all help prevent constipation and bloating. Only feed what the group clears in two to three minutes; uneaten food fouls the water and overfeeding is the single most common cause of health problems in guppies, leading to fatty liver, bloat and poor water quality. A single fasting day each week is a simple, effective routine. Fry need infusoria, microworms and powdered flake from day one, and gravid females benefit from extra frozen food to support healthy fry development.
• Care & Maintenance: Keep guppies in groups of at least six, with a ratio of two to three females per male to spread attention and reduce stress on individual fish. A 40–60 litre aquarium suits a small group, and a tight-fitting lid is essential because guppies can and do jump. Furnish the tank with live plants, floating cover, gentle filtration and moderate flow, and avoid strong currents that tire these small swimmers. Perform a 25–30% water change weekly, siphon the substrate, and rinse filter media in tank water only. Always quarantine new arrivals for two to four weeks and drip-acclimatise them over 30–45 minutes before release. Watch for telltale signs of trouble — clamped fins, white spots, frayed tails, lethargy or gasping at the surface — and act quickly, as guppies can decline fast. Common issues include ich, fin rot and columnaris, most of which trace back to stress or poor water quality. With good care, expect a lifespan of two to three years, and be prepared for regular fry, as females store sperm and can produce young for months after a single mating.