Fantail goldfish
Carassius auratus
intermediate careOverview
The fantail goldfish (Carassius auratus) is usually the first fancy goldfish keepers recommend — the hardiest and most forgiving of the egg-shaped, twin-tailed varieties. It has a rounded body and a split, fanned tail, reaches 15–20 cm, and lives 10–15 years. Fantails are slower and more delicate than single-tailed goldfish, but they are far tougher than the more extreme fancies, making them a sensible starting point for cold-water fishkeeping.
Tank & water
Give one fantail 75 litres (20 gallons) and add about 40 litres per extra fish. Priorities:
- No heater needed: fantails are cold-water fish; a steady 18–23 °C (the warm end of the goldfish range) suits fancies well.
- Strong, gentle filtration: they are messy but poor swimmers, so use a good external filter and temper the flow.
- Smooth décor: round-bodied fancies bump into things — avoid sharp ornaments.
Feeding
Fantails are omnivores. A quality sinking goldfish food is best — floating pellets make round-bodied fish gulp air and can trigger buoyancy problems. Add blanched peas (a classic remedy for constipation and floating) and other soft vegetables, plus occasional frozen treats. Feed small amounts once or twice a day and remove leftovers. Stay on top of maintenance and water testing.
Tankmates
Keep fantails with other fancy goldfish of similar swimming ability — orandas, ryukins, black moors and other twin-tails. Never house them with fast single-tailed goldfish like comets and shubunkins, which will out-compete these slow feeders. They are not tropical community fish. A small group of fancies in a spacious tank is the ideal — plan numbers with how many fish in an aquarium.
Because they are the toughest of the fancies, fantails are the variety most likely to succeed for a keeper new to cold-water fish, and a well-kept pair or trio makes a lovely, low-drama display. Just remember that “hardy for a fancy” still means a slow, round-bodied fish that needs sinking food, gentle flow and clean water — treat it with the same care as its more delicate cousins and it will reward you for a decade or more.
Fantail goldfish — frequently asked questions
How big do fantail goldfish get?
Fantails reach around 15–20 cm as chunky, egg-shaped fancy goldfish. They stay smaller than single-tails but are still substantial, heavy-waste fish that need a large tank — see how big do goldfish get.
Do fantail goldfish need a heater?
No. Fantails are cold-water fish, but as a fancy variety they prefer the warmer end of the goldfish range, around 18–23 °C, and dislike sudden chills. In most homes they need no heater at all — see do goldfish need a heater.
Why does my fantail float or struggle to swim?
Round-bodied fancies like fantails are prone to swim-bladder problems, often from gulping air with floating pellets. Feed a good sinking food and soak or pre-sink pellets before feeding to help prevent it.
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