Quick Stats
| Adult Size | 20–30 cm |
| Minimum Tank | 40 gal |
| Temperature | 15–22°C |
| pH Range | 7.0–8.4 |
| Hardness (GH) | 10–20 dGH |
| Difficulty | Easy |
| Temperament | Peaceful |
| Diet | Omnivore — goldfish pellets, blanched vegetables, earthworms |
| Schooling | Keep in groups of 3+ |
Tank Setup
The Goldfish (Single Tail) (Carassius auratus) requires a minimum tank size of 40 gal. For a species this size, a larger tank is always better — more water volume means more stable parameters and a healthier environment.
Water parameters should be maintained within the following ranges: temperature 15–22°C, pH 7.0–8.4, and hardness 10–20 dGH. These are relatively tolerant fish that adapt to a range of conditions.
Provide appropriate hiding places, a suitable substrate, and open swimming space to match the natural behaviour of this species.
Tank Mates
Goldfish (Single Tail) are peaceful fish. They work well in community tanks with similarly-sized peaceful species.
Compatible tank mates include: Other Single-Tail Goldfish, Weather Loach, Hillstream Loach (cooler water). Avoid housing with aggressive or much larger fish.
Schooling requirements: Keep in groups of 3+. Keeping them in adequate numbers is essential for their wellbeing.
Diet & Feeding
Goldfish (Single Tail) are Omnivore. Feed a varied diet to ensure optimal health and colouration.
Omnivore — goldfish pellets, blanched vegetables, earthworms
Feed small amounts 1–2 times daily. Only provide what the fish can consume within 2–3 minutes to prevent overfeeding and water quality issues.
Common Health Issues
Like all aquarium fish, Goldfish (Single Tail) can be susceptible to common diseases including ich (white spot disease), fin rot, and bacterial infections. This species is generally hardy and disease-resistant when kept in good conditions.
Prevention is always better than treatment. Maintain stable water parameters, avoid overfeeding, quarantine new fish before adding them to the main tank, and perform regular water changes. A regular maintenance routine will prevent most health issues.
If disease does occur, isolate affected fish in a quarantine tank and treat appropriately. Always research medication compatibility before use — some treatments are toxic to invertebrates and scaleless fish.
Breeding
Breeding Goldfish (Single Tail) is possible in the home aquarium.
Provide appropriate breeding conditions — planted areas with fine-leaved plants. Condition breeding pairs with high-quality foods before attempting to spawn them.
Many Goldfish (Single Tail) will breed readily without intervention. Be prepared to remove eggs or fry if you want to raise them — adult fish may eat their own young.
Frequently Asked Questions
What size tank does a Goldfish (Single Tail) need?
A Goldfish (Single Tail) needs a minimum tank size of 40 gal. However, larger is always better — more water volume means more stable water parameters and healthier fish.
Are Goldfish (Single Tail) easy to keep?
Goldfish (Single Tail) are rated as Easy difficulty. Beginners can keep them successfully with proper research and a cycled tank.
What do Goldfish (Single Tail) eat?
Goldfish (Single Tail) are Omnivore. Feed a varied diet including goldfish pellets, blanched vegetables, earthworms.
Can Goldfish (Single Tail) live with other fish?
Goldfish (Single Tail) are peaceful. Compatible tankmates include: Other Single-Tail Goldfish, Weather Loach, Hillstream Loach (cooler water). They work well in community tanks with similarly-sized peaceful fish.