It’s not advisable to keep neon tetras and goldfish in the same tank. Because both fish species have different needs, living together can put them in danger.
Neon tetras and goldfish are both social, playful, and peaceful fish. Not only do they bring their own unique colors and personalities to the aquarium. They’re also low-maintenance and quite affordable.
These two species may appear to be perfect tank mates. Neon tetras and goldfish, unfortunately, don’t share the same living conditions and environments. As a result, they can’t thrive sharing the same tank.
Let’s take a more in-depth look into the reasons why neon tetras can’t live with goldfish.
Can Neon Tetras Live With Goldfish?
Neon tetras can’t and shouldn’t live with goldfish. While they’re both peaceful and may get along, it’s impossible to create conditions in the tank that allow both species to thrive. So, keeping neon tetras and goldfish in the same tank can put their health at risk.
What’s more, because goldfish can be insatiable, they may mistake the much smaller neon tetras for food.
Here’s an overview of the reasons why neon tetras can’t live with goldfish:
- Mature goldfish are significantly larger than neon tetras.
- Goldfish, due to their size, require a larger tank than neon tetras.
- Neon tetras aren’t finicky with their food, while goldfish have specific dietary needs.
- Both species have different water requirements.
- Goldfish produce large amounts of waste, which can be detrimental to neon tetras.
- Together, neon tetras and goldfish have lower disease resistance.
- Both species have different temperaments.
Size Difference
One of the main factors neon tetras and goldfish shouldn’t live together is their huge size difference.
In a tank, the common goldfish can grow up to 6–8 inches long. The average size of neon tetras, on the other hand, is around 1.5 inches long.
In extremely rare cases, neon tetras can grow to around 1.75 to 2.5 inches long. That’s still much shorter than the smallest goldfish species, which can grow to be six inches long.
Because goldfish are big and omnivorous, they tend to view smaller fish like neon tetras as snacks.
If you don’t take into account the other factors, you may get away with pairing neon tetras and goldfish for the first four to six months of their lives.
During that age, goldfish are around the same size as neon tetras. They also don’t cause as much mess as adult goldfish.
However, goldfish will eventually outgrow the neon tetras. So, when they reach a medium size, it’s best to move them to a separate tank. Otherwise, some neon tetras might end up as goldfish dinner.
Tank Size
Almost no fish species can thrive in a confined space. So, both neon tetras and goldfish need their space to swim freely.
However, because goldfish are significantly larger than neon tetras, they require a larger tank that’s at least 30 gallons.
Goldfish also grow much faster than neon tetras. To avoid stress, they must be kept in large tanks.
Neon tetras value their space as well and should be kept in groups of at least six tetras. Still, given their small size, neon tetras can thrive in a 10-gallon tank.
Dietary Requirements
Both neon tetras and goldfish are omnivorous fish that will eat almost anything that comes their way. That said, they have different dietary requirements to stay healthy.
To begin with, goldfish are prone to digestive issues as a result of poor feeding habits. That’s why it’s preferable to feed goldfish food made specifically for them.
Goldfish pellets and flakes are usually sufficient. The occasional live food treat should provide extra nutrients while causing no digestive issues.
Neon tetras, on the other hand, aren’t picky about their food as long as it contains enough protein. So, in addition to tropical fish flakes, neon tetras should have the following treats 2–3 times per week:
- Brine shrimp
- Daphnia
- Freeze-dried bloodworms
This tropical diet contains at least 44% protein, which is higher than the protein requirements of goldfish.
Water Temperature Requirements
One of the main reasons neon tetras and goldfish can’t coexist in the same tank is water temperature.
Goldfish are cold-water fish species, so they thrive in water temperatures from 68°F to 74°F. Warmer temperatures can hasten their already rapid growth. As a result, the goldfish can suffer from defects and deformities.
Neon tetras, on the other hand, thrive in warmer water temperatures ranging from 72°F to 76°F. If the temperatures drop, neon tetras may have difficulty digesting their food. It also increases the tetras chances of getting sick.
Water Change Frequency
Goldfish by nature create a messier environment. Whereas goldfish eat a lot and thus produce a lot of waste, neon tetras eat less and thus produce less waste.
What’s more, because goldfish are voracious eaters, they swim around moving tank decorations and plants in search of food.
As a result, a tank with goldfish will require frequent upkeep to maintain a healthy environment for the tank inhabitants.
These frequent water changes will most likely stress neon tetras. Stressed neon tetras can develop health problems and become more susceptible to diseases.
Disease Transmissibility
In general, goldfish have lower disease resistance in warm water temperatures. Neon tetras also become more susceptible to illness in unfavorable water conditions.
Pairing neon tetras with goldfish will most almost certainly result in poor living conditions for both fish. As a result, they’re more likely to become stressed, which reduces their disease resistance.

Different Temperaments
Neon tetras are shoaling fish, which means they need to live with a group of their own to thrive. Most goldfish, on the other hand, live a long, healthy, and happy life on their own.
On top of that, neon tetras are very active swimmers, which can be a bit too much for goldfish. While goldfish aren’t sluggish, they aren’t the most active swimmers unless they’re looking for food.
Even if there weren’t such significant differences between the two species, neon tetras and goldfish may not be compatible based solely on temperament.
In Conclusion
Neon tetras and goldfish are both bright, colorful fish that are known for their peaceful temperament. However, that’s where their similarities end.
Goldfish can only thrive in colder water, whereas neon tetras thrive in warm water. What’s more, goldfish are larger and more voracious than neon tetras. As a result, the small tetras are in constant danger of being eaten.
With these significant differences, it’d be unfair to keep both neon tetras and goldfish in the same tank.
So, if you want to raise both species, you should get them their own tanks. This way, you can provide them with the best possible environment for healthy growth.