Goldfish
Carassius auratus
Also sold as Comet · Oranda · Ryukin · Ranchu · Shubunkin
Synonyms Fancy goldfish · Common goldfish · Black moor · Fantail goldfish · Lionhead goldfish · Pearlscale goldfish
Goldfish (Carassius auratus) is a peaceful freshwater fish that reaches about 20 cm (7.9 in) and swims in open water. It wants 50–73°F (10–23°C) and pH 7–8, is kept in groups of 2 or more, and needs a tank of at least 150 L (40 gal).
At a glance
| Type | Fish |
|---|---|
| Adult size | 20 cm (7.9 in) |
| Minimum tank | 150 L (40 gal) |
| Group size | 2 or more |
| Temperature | 50–73°F (10–23°C) |
| pH | 7–8 |
| Temperament | Peaceful |
| GH | 5–20 |
| Eats shrimp | Yes |
Before it goes in
- Goldfish needs at least 150 L (40 gal). The smallest size in this library that clears that is the 40 Gallon Breeder.
- Keep 2 or more. Below that it hides, colours down and is far more likely to be picked on.
- It eats small fish and shrimp — anything under about 6.7 cm (2.6 in). In this library that means Cherry Shrimp, Rummy Nose Tetra and Crystal Red Shrimp.
- It holds at 50–73°F (10–23°C). That shares a window with Cherry Shrimp and Common Pleco, but not with Betta and Angelfish.
- It digs in the substrate. A freshly planted carpet — Dwarf Hairgrass Mini and Downoi — gets lifted before it roots.
- It eats most plants. Hygrophila corymbosa 'Siamensis' and Bacopa caroliniana will not last with it; tough-leaved Anubias nana 'Petite' and Marimo Moss Ball will.
- Before you buy: it is a cold-water animal, so a typical tropical planted tank runs too warm for it.
- A group of 2 takes up roughly 60% of what a 40 Gallon Breeder will comfortably hold, so plan the rest of the stock around it.
What tank size does it need?
At least 150 L (40 gal). The smallest size here that clears it is the 40 Gallon Breeder.
How many should I keep?
2 or more. Fewer than that and it spends its time hiding instead of out in the open.
Will it eat shrimp?
Yes. Shrimp are food to it, so pick one or the other.
What water does it want?
50–73°F (10–23°C), pH 7–8, GH 5–20.
Good tank mates
- Tank mates from this library that share its temperature window, are peaceful and eat neither it nor its young: Bristlenose Pleco, Celestial Pearl Danio, Otocinclus, Ramshorn Snail and Julii Cory.
- Plants that hold up with it: Anubias nana 'Petite', Marimo Moss Ball, Subwassertang and Anubias barteri.
Often compared with
| Goldfish | Discus | Elephantnose Fish | |
|---|---|---|---|
| Adult size | 20 cm | 20 cm | 22.5 cm |
| Min tank | 150 L | 300 L | 243 L |
| Group | 2+ | 6+ | 1+ |
| Temperature | 50–73°F (10–23°C) | 82–88°F (28–31°C) | 73–82°F (23–28°C) |
| Eats shrimp | Yes | Yes | Yes |
More livestock
Sources (4) · checked Sep 2026
- Mature tank, Temperatureaquariumcoop.com
- What it eatsaquariadise.com
- Mature tankaquariumcodex.com
- What it eatsaquariumstoredepot.com