White Comet Goldfish (Carassius auratus)

Bring a pure white comet to a dark pond

The White Comet Goldfish is an all-white form of the comet goldfish, Carassius auratus. It has the comet's slim, streamlined body and long, deeply forked tail, but no red or orange at all: the scales carry a soft pearly sheen, the fins are translucent white and the dark eye stands out against the pale head. Against a black pond liner or a deep green planted margin, a white comet catches the light every time it turns, which makes it one of the easiest pond fish to watch from a distance.

Comets come in many colours. Wikipedia's comet goldfish article, drawing on Johnson and Hess's Fancy Goldfish and Chris Andrews's guide, lists yellow, orange, red, white and red-and-white as common, and describes the comet as slightly smaller and slimmer than the common goldfish, from which it was developed in the United States in the 1880s. Practical Fishkeeping puts it simply: any goldfish with the forked comet tail is a comet, whatever its colour, and a good tail is well spread and does not droop or overlap.

Tell a white comet from similar pale goldfish

For a contrasting partner, see our Bronzed Comet Goldfish, the same shape in metallic bronze, or compare the types in our comet goldfish guide. All our pond and fancy goldfish are listed under goldfish.

Know what arrives: one young comet at 2–3 in

Each purchase supplies one live White Comet Goldfish at 2–3 in, about 5–8 cm, measured nose to tail. That is a young fish with most of its growing ahead of it. Sex is not chosen or guaranteed; the differences only show once fish mature, and are covered in the breeding section below. Individual fish vary a little in the strength of the sheen and the clarity of the fins, so the photographs show the colour form rather than the fish you will receive.

Build a mixed group of single-tails

• Keep company: the Maidenhead Aquatics fish database recommends keeping goldfish in groups and says mixed varieties are fine.
• Match sizes: add fish of a similar size at the same time, so small newcomers are not crowded out at feeding.
• Mix colours: white, bronze, red and red-and-white comets share the same care, so one group can hold several colours.
• Stay single-tailed: comets, common goldfish and shubunkins suit each other; twin-tailed fancies need a separate home.

Check our delivery and Live Arrival Guarantee page for dispatch days before you order.

Give a small fish room for a 30 cm adult

A 2–3 in comet grows into a large, long-lived fish. OATA gives up to 30 cm as the most common maximum body length of pond goldfish, Practical Fishkeeping says comets reach up to 35 cm and regularly 30 cm, and FishBase records 48 cm total length as the species maximum. OATA reports goldfish living up to 20 years in a healthy pond, while Wikipedia gives comets 5–14 years and longer in ideal conditions. Plan the pond for the adult, not for the fish in the bag.

Use a stocking table

The Maidenhead Aquatics pond guide suggests 25 cm of fish per 455 litres (100 imperial gallons), counted at adult size. Applied to adult comets of 30 cm, that gives:

Treat this as a starting point: the OATA garden pond guide says it is not possible to say exactly how many fish a pond can hold, because filtration, plants and feeding all play a part. Work out your litres with our tank volume calculator and add any other fish with our stocking calculator.

Protect a white fish from herons and cats

A pale fish is easy to see from above. That is the appeal of a white comet, but it also means herons, cats and other visitors will find it. OATA recommends netting a pond to stop wild birds or animals taking fish, especially in winter when there is little plant cover, and the OATA garden pond guide lists the practical options.

Layer the defences

Plants help too. The Maidenhead Aquatics pond guide aims for about 33–50% of the surface covered with vegetation, which gives a white fish somewhere to slip out of sight.

Site and build the pond for comets

OATA recommends fish ponds at least 45–60 cm deep, and the garden pond guide asks for at least 60 cm in some parts, because depth keeps temperatures steadier in heat and frost. Choose a level spot with about four to six hours of sun and some shade, away from trees that drop leaves. Add shallow ledges for marginal plants and a mix of submerged and floating plants: OATA notes that live plants add oxygen, remove pollutants and provide food and shelter. Any pond with fish needs a filter, and a pump or fountain keeps the water moving and oxygenated.

Keep the water steady through the year

Comets cope with a wide range, which is why they live outdoors in the UK, but each source draws the range a little differently.

Separate habitat values from waste readings

pH and hardness describe the kind of water; a pH of 7.5–8.0 satisfies every source above. Ammonia, nitrite and nitrate measure waste, and those are the readings that make goldfish ill. Treat all tap water with a conditioner before it goes in, as OATA advises, and check your water company's postcode report. Our water matcher and water chemistry guide help you read the results, and test kits and conditioners are in our water care and treatment range.

Run a weekly pond log

OATA advises testing ammonia, nitrite, nitrate, pH and hardness every week, especially while a pond is new and after adding fish, and recording the results so changes stand out. A new pond should run with conditioned water and working equipment for at least 24 hours before fish go in, and a full fishless cycle takes several weeks; our nitrogen cycle article explains why.

Act on each reading

Our aquarium filtration guide covers how biological filters work, and the same principles apply to a pond.

Feed for the size of fish and the season

Goldfish are omnivores. FishBase records wild fish eating plankton, bottom-living invertebrates, plants and detritus, and Practical Fishkeeping says comets take a wide range of dried and frozen foods. OATA notes that different pellet sizes suit different sizes of fish, which matters for a 2–3 in comet: start with a small food and move up as it grows.

Build one measured meal

• Young fish: Tropical Super Goldfish Mini Sticks or Tropical Goldfish Pellet.
• Larger fish in summer: a floating staple such as Tropical Pond Sticks Mixed.
• As the water cools: Tropical Koi & Goldfish Wheat Germ & Garlic, the lower-protein type OATA recommends.
• Portion: once a day, only what is eaten within a few minutes.
• Cold water: OATA says it may be better not to feed below 8°C; the Maidenhead Aquatics pond guide feeds wheatgerm only at around 10°C and returns to normal food above 10–15°C.

Browse our fish food range for other sizes.

Settle it in, outdoors or indoors

In the warmer months, introduce the fish straight to the pond. OATA's method is to keep the bag out of bright light, float it for 10 minutes, add small amounts of pond water to the bag, then release the fish with as little bag water as possible. Our guide on how to acclimatise new fish shows each step. The OATA garden pond guide advises against adding fish in winter, when their immune system is inactive.

A small comet can also be grown on indoors first. The Maidenhead Aquatics database suggests starting small comets in a large aquarium and moving them to a pond as they grow, and OATA's aquarium sheet says non-fancy goldfish can be moved to an outdoor pond. Allow at least 100 litres for one goldfish and 50 litres more for each extra adult, with a filter and a 25% water change each week; move the fish out in spring once the pond and tank temperatures are close.

Use a first-week checkpoint plan

Choose companions that share the pace

OATA advises against keeping comets with fancy goldfish, because comets swim faster and often outcompete them for food, and some boisterous fish nip the fins of fancies; Practical Fishkeeping says the same about twin-tailed goldfish. Most pond fish otherwise live together well, OATA says, although they may need slightly different conditions.

Screen each companion

Try a planned mix in our tank mates tool, or browse goldfish and coldwater fish and the cold water fish A–Z.

Read health signs on a white fish

A white body shows changes clearly, which helps you catch problems early. OATA lists the signs of a healthy fish as clear, bright eyes, undamaged fins, intact scales with no ulcers or bumps, normal swimming and steady breathing, and warns about clamped fins, flicking and shimmying. Practical Fishkeeping advises against buying comets with visible blood in the fins.

Pair each sign with an action

Breed responsibly and never release

Goldfish are the pond fish most likely to spawn. OATA says spawning can happen on its own when the temperature is right and males outnumber females, and suggests a shallow, heavily planted area because adults eat eggs and fry. The Maidenhead Aquatics database puts the start of spawning chases at 15°C and above, with eggs hatching in 48–72 hours. Practical Fishkeeping notes that mature males develop white tubercles on the gill covers and ridges on the pectoral fins, while females turn plump with eggs, and that comets cross freely with common goldfish and shubunkins, so mixed ponds produce mixed young.

In England and Wales, government guidance lists goldfish among the non-native fish you can keep without a licence. OATA states that releasing fish into the wild is illegal, and FishBase records goldfish as a potential pest where introduced. Rehome surplus fish through another pond keeper or a local aquatic shop.

Answer White Comet Goldfish buying questions

What is a White Comet Goldfish?

It is an all-white colour form of the comet goldfish, Carassius auratus: a slim, single-tailed goldfish with a long, deeply forked tail. It is a hardy pond fish whose care is the same as any other comet.

How big does a White Comet Goldfish grow?

Usually to about 30 cm. OATA gives up to 30 cm as the most common maximum for pond goldfish, Practical Fishkeeping says comets grow to 35 cm, and FishBase records 48 cm for the species.

Is a white goldfish more at risk from herons?

A pale fish is easy to see from above, so protect the pond well. OATA suggests heron netting with a 15–100 mm square mesh held 30 cm above the water, or single-strand low-voltage fencing, plus plants for cover.

Can a White Comet live outside in winter?

Yes. Comets are hardy pond goldfish. In a filtered pond at least 45–60 cm deep they rest near the bottom in winter; keep part of the surface free of ice and stop or reduce feeding in cold water.

Can I grow it on indoors before it goes in the pond?

Yes. The Maidenhead Aquatics database suggests starting small comets in a large aquarium and moving them to a pond as they grow, and OATA says non-fancy goldfish can be moved to an outdoor pond. Allow at least 100 litres for one goldfish.

Why has my white comet developed black marks?

Practical Fishkeeping explains that goldfish can gain temporary black pigment after stress or treatment, as an outward sign of healing, usually lasting days or weeks. Test the water to find out what caused the stress.

Can it live with fancy goldfish?

It is better not to. OATA and Practical Fishkeeping both advise keeping comets apart from twin-tailed fancy goldfish, which are slower and lose out at feeding time.

How many fish come with one purchase?

One live White Comet Goldfish at 2–3 in (about 5–8 cm). Sex is not chosen or guaranteed.

Consult the care references

• OATA: How to look after pond fish — UK guidance on pond fish water values, sizes, group sizes, pond volume and depth, seasonal feeding, winter care, health signs and breeding.
• OATA: How to set up and look after your garden pond — UK guidance on siting, building, maturing and stocking a garden pond, adding fish and keeping herons and otters out.
• OATA: How to look after goldfish in an aquarium — UK guidance on goldfish in aquariums: volume per fish, water values, weekly maintenance and keeping comets apart from fancy goldfish.
• Practical Fishkeeping: Comet goldfish — what makes a comet, sarasa colouring, adult size, pond and aquarium space, water, diet, companions and sexing.
• Practical Fishkeeping: Will my red, black and white goldfish lose the black colour with age? — why black colour in goldfish often fades over time, faster in warmer water, and how temporary stress black appears.
• Maidenhead Aquatics fish database (fishkeeper.co.uk): Sarasa Comet — sarasa comet size, temperature, pH, pond depth, companions, colour development, spawning and lifespan.
• Maidenhead Aquatics: Taking care of goldfish in a pond — pond stocking rule, filter cleaning, seasonal feeding temperatures, oxygen and plant cover for goldfish ponds.
• FishBase: Carassius auratus — native range, maximum length and age, water values, wild diet and the pest risk when goldfish are released.
• Wikipedia: Comet (goldfish) — history of the comet goldfish, its body and tail, colour forms including the sarasa, and lifespan (citing Johnson & Hess and Andrews).
• GOV.UK: Introduce or keep non-native fish — England and Wales guidance listing goldfish and ide or orfe among the non-native fish you can keep without a licence.
• Tropical Fish Co delivery policy — current dispatch days and Live Arrival Guarantee terms.