Can Goldfish And Tetras Live Together? Why Or Why Not?

It’s no question that people enjoy mixing different kinds of fish together. If you’ve made it to this page, you’re probably one of them!

Goldfish and tetras are both very beautiful, but very different species of fish. So, is it okay to house goldfish and tetras together?

Why Shouldn’t Goldfish And Tetras Live Together?

Goldfish and tetras shouldn’t live together because their habitat requirements are different. To make one fish happy, you’re going to have to sacrifice the needs of the other. This isn’t a good thing to do as you should strive to keep all your fish happy and healthy.

Tetra Care Requirements

Tetras are tropical fish that natively live in the Americas and Africa. Most of them come from the river systems in South America like the Amazon river basin.

Because of this, they need warm water provided by a heater. The ideal temperature for tetras is going to be between 75° and 80° F. Anything colder than that, and their immune system will suffer. So, they’ll be likely to become sick.

Tetras also need tropical flakes as their staple food. Tropical flakes are high in protein and low in vitamins. This is perfect for tetras, but not for goldfish. Goldfish don’t digest protein well, and they need high levels of vitamins.

Goldfish Care Requirements

Goldfish are coldwater fish that are native to parts of Eastern Asia. Today, they live in many places around the world. But, they primarily live in temperate environments.

As such, the best temperature for fancy goldfish is between 65° to 74° F. Comets and shubunkins can stand water that is a bit colder, with optimal temperatures of 60° and 70°F.

Goldfish can stand warmer temperatures, but that doesn’t mean they do well in heated tanks. Water that is too warm will lower the immune system of your goldfish.

Tetras can do well in smaller (10-20 gallon tanks), but goldfish need larger aquariums. You should have at least 30 gallons for a single goldfish. You should add an extra 10 gallons to that for every other goldfish you add to the tank.

Unlike what most people think, goldfish don’t “grow to the size of their tank”. Most grow about 6-8 inches long, with many growing even larger than that. If you were to attempt housing goldfish and tetras together (this isn’t a good idea), you’d need a very large tank.

Goldfish also shouldn’t eat the high-protein diet of tropical flakes. Instead, they should get goldfish-specific food. This food is lower in protein and high in vitamins which is easier for them to digest.

Goldfish Will Make The Water Too Dirty

A goldfish’s digestive system doesn’t work the same way that tropical fish do. They don’t have stomachs. So, the food passes through their body more quickly, and they have to eat more than the typical fish.

This also means that they produce more waste.

You might’ve heard that goldfish are “dirty” fish. They poop a lot, so you need to clean their tank more often, and they need the best filtration. Usually, these conditions aren’t the best for tropical fish like tetras. They tend to be particularly sensitive to water quality.

Goldfish May Eat The Tetras

While the goldfish are small, they may be able to live somewhat happily with tetras. But, goldfish are opportunistic eaters. They will eat just about anything that will fit in their mouth. Goldfish also grow very large, unlike tetras. So, once the goldfish get large enough, your tetras are likely to become a snack.

Tetras Can Be Nippy

Fancy goldfish have compact and robust bodies that aren’t good for swimming. Combine their awkward bodies with their long, flowy fins, and you have a fish that can’t swim well or quickly at all.

Tetras are generally considered peaceful. But, there are kinds that can be especially nippy. Tetras are also quick swimmers, unlike fancy goldfish. So, your goldfish’s fins are likely to get torn up, leaving them susceptible to infection.

What Can You House With Goldfish Instead?

It’s better to keep goldfish with goldfish and tetras with other tropical fish. There are so many different varieties of goldfish. So, you shouldn’t ever get tired of housing them together.

Likewise, there are so many different kinds of tropical fish that go really well with tetras.

There’s really no reason to try and mix the two. Your fish will be happier if you get them tank mates that are well suited for them.


Unfortunately, it’s not a good idea to try and house goldfish and tetras together. The main reason is that they have completely different housing requirements.

Goldfish like cold water, tetras like warm water. Goldfish need lots of fiber, while tetras need more protein. These are just a few examples.

It’s simply a better idea to keep the two apart.

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