Cold Water Fish for Sale UK

No — goldfish are coldwater fish and thrive at 18–22°C, which matches most UK indoor room temperatures year-round. Fancy varieties like Orandas prefer the warmer end of that range and can benefit from a heater set low (around 20°C) in colder houses, but they do not need tropical temperatures.

A single fancy goldfish needs at least 75L, with 40L added for every additional fish. Single-tail goldfish (Comets, Shubunkins) grow over 25cm and really belong in ponds or very large tanks of 200L+. The goldfish bowl is a myth that leaves fish stunted and unwell.

Only as young juveniles and for a limited time. Koi grow to 60–90cm and live 30+ years — they need a pond of at least 1,000L per fish with proper filtration. Young koi in tanks should be moved outside once they outgrow an indoor setup, typically by 15–20cm.

Weather Loaches, White Cloud Mountain Minnows and Rosy Barbs tolerate the cooler water that goldfish prefer, but you need a large tank with good flow. Avoid small fish that goldfish can swallow — goldfish mouths grow fast and anything under 3cm is potential food.

Feed adults once or twice a day, only what they eat in two minutes. Goldfish are greedy and will overeat, fouling the water. Skip a day each week to aid digestion. Vary between sinking pellets, frozen bloodworm and blanched vegetables for balanced nutrition.