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- Vendor: Squeaky's Aquatics
Comet Goldfish (Carassius auratus)
Comet Goldfish (Carassius auratus) is the classic long-finned, single-tailed goldfish, a fast and hardy swimmer that brings bright orange color to ponds and large coldwater aquariums. Comets are tough, inexpensive, and endlessly entertaining, but they grow big and produce a lot of waste, so they need plenty of space and strong filtration rather than a bowl. Sold at roughly 3 to 4 inches. Browse the rest of our freshwater fish.
Care Guide
- Give them space: Comets reach 8 to 12 inches and are built to swim. Plan on a stocked pond or a 40 gallon-plus tank with room to grow, adding volume for each additional fish.
- Strong filtration: They are messy eaters. Over-filter and keep up with water changes to control the ammonia and nitrate they generate.
- Coldwater fish: They thrive at room temperature and do not need a heater. Avoid housing them with tropical community fish that need warmer water.
- Diet: Feed a quality sinking goldfish pellet plus blanched veggies and occasional treats. Avoid overfeeding floating flakes, which can contribute to swim-bladder issues.
Specifications
| Common Name | Comet Goldfish, Comet |
| Scientific Name | Carassius auratus |
| Origin | Domesticated (China) |
| Care Level | Beginner |
| Temperament | Peaceful |
| Adult Size | 8 to 12 in |
| Minimum Tank Size | 40 gallons or pond |
| Temperature | 50 to 75F (coldwater) |
| pH | 6.5 to 8.0 |
| Diet | Omnivore |
| Sold As | 3 to 4 in each |
Compatibility
Comets are peaceful but big, fast, and cold-preferring, so they belong with their own kind rather than small tropical fish. House them with other single-tailed goldfish, Koi, and Shubunkins in ponds and large tanks. Avoid mixing them with slow fancy goldfish (which cannot compete at feeding time) or small tropicals like tetras.
Recommended Foods & Supplies
- Quality sinking goldfish or pond pellets as a daily staple
- Hardscape and decor for a naturalistic pond or tank
- Robust filtration and regular water changes to handle their waste
- More freshwater fish
FAQ
Can a Comet live in a bowl or small tank?
No. Comets grow large and are strong swimmers that quickly outgrow small setups. A pond or large aquarium with good filtration keeps them healthy.
Do they need a heater?
No. Comets are coldwater fish and do best at room temperature or in an outdoor pond.
Will they get along with my tropical community fish?
Not ideally. Their size, speed, and preference for cooler water make them a poor match for small warm-water community fish.
How big do they really get?
In enough space a Comet can reach 8 to 12 inches, so plan for their adult size from the start.
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Comet Goldfish (Carassius auratus)
