Are Neon Tetras Cold Water Fish?

Neon tetras aren’t considered cold-water fish because they can’t tolerate temperatures lower than 60 °F. They’re originally from South American forests, so they’re used to a warm, tropical climate. Low water temperature can cause severe adverse effects to neon tetras, so you’ll need to install a heater if you’re living in a cold region.

Neon tetras are a brilliant addition to any tank. Their fast-paced movement is entertaining to watch.

Yet, to maintain this vitality, neon tetras need optimum conditions. So, are neon tetras cold water fish?

In this article, we’ll explain why neon tetras require warm water and how to maintain the temperature within a tolerable range.

Are Neon Tetras Cold Water Fish?

Cold water fish are categorized differently based on context. In the aquarium context, cold water fish are species that don’t require heaters to be able to live indoors.

Here’s why neon tetras don’t belong to cold water fish:

Place of Origin

When South America comes to mind, we think of tropical fruits, dense bushes, and, most importantly, hot, humid weather. This continent is home to neon tetras, who are native to the Amazon basin.

More specifically, this species lives in western Brazil, southeastern Colombia, and eastern Peru. The temperatures of the water there range between 68 and 79 °F.

Breeding Conditions

Nowadays, most neon tetras in pet shops aren’t imported from their native land in South America. Instead, they’re mostly bred in Eastern Europe and the Far East.

Still, warm water is necessary for fulfilling their breeding conditions. Besides complying with the required hardness and PH conditions, the water temperature should range from 72 °F to 75 °F.

Neon Tetra Fish

Neon Tetras Need Heaters

As mentioned earlier, cold water fish don’t require heaters. For example, goldfish are among the most common aquarium species that belong to this group.

Conversely, neon tetras need heaters, especially if you live in the colder parts of the country.

Adverse Effects from Cold Water

For neon tetras, warm water isn’t just a preference. If the temperature drops below their tolerable range, neon tetras can suffer extreme adverse effects.

Here’s what cold water can do to neon tetras.

Slowing Down

As the water becomes colder, the metabolism of your neon tetras will slow down, making them less active than normal. Not only will the reduced activity make them less interesting in your tank, but it will also slow down their digestion, respiration, and growth.

Loss of Appetite

Slow growth is partly related to eating less. Most fish species will lose appetite if they’re placed in a harsh environment.

This includes incompatible tank mates as well as wrong temperature ranges. For this reason, if you notice your neon tetras aren’t eating their typical portions, check the water temperature.


As their metabolism slows down in cold water, neon tetras may become pale and develop several illnesses. If these conditions persist for a long period, neon tetras may eventually perish.

Even more seriously, a sudden drop in temperature can speed up adverse effects and cause irreversible harm to your fish. Therefore, if you’re using a heater, you need to maintain consistency to avoid harming your fish.

How to Maintain the Right Temperature for Neon Tetras?

Depending on where you live, you’ll have to adjust your tank’s temperature for fish that come from a different climate. Otherwise, you can limit your tank community to local varieties, which are more likely to thrive in your home without high heating costs.

As for neon tetras, pet owners in colder regions need to heat their tank’s water. Here’s what you need to optimize the temperature for your neon tetras.

Purchase Helpful Tools

Anytime you purchase a tank, you’ll need two additional vital items. First, search for a reliable aquarium heater in pet supply shops.

Second, you need to purchase a thermometer to regularly check the water temperature and ensure the heater is working consistently. However, note that overheating is equally harmful to neon tetras, so keep an eye on the upper limit of the temperature range.

Carefully Change the Water

All fish require routine water changes to dispose of waste from their tanks. Neon tetras even need more attention to their water quality as they originally come from clear water streams in the Amazon basin.

When changing water, make sure you don’t change the whole tank volume at once. Instead, we recommend replacing only a quarter of the total volume to avoid sudden changes in temperature.

Admittedly, changing a fraction of the tank’s water won’t make a big difference, so you’ll have to increase the frequency of changes. We recommend replacing the water for neon tetras once per week.

Neon Tetra Fish

Frequently Asked Questions

What is the maximum temperature for neon tetras?

Although some guides recommend up to 80°F for neon tetra tanks, this temperature isn’t suitable for tetras in general. At 80° F, there’s a risk that your fish will have increased metabolism and stress, which will affect their health.

It’s best to keep the tank temperature below 78° F to suit neon tetras.

Do neon tetras need heaters?

Yes, neon tetras need heaters if you’re living in a cold region and can’t maintain a water temperature of at least 68 degrees. Therefore, they can’t share the same tank with cold water fish, like goldfish.

What to do if the fish tank heater stops working?

If your tank heater breaks or there’s a power cut in your region, immediately cover the tank. Then, keep checking the thermometer and gradually add warm water to the tank when needed.

Wrap Up

Finally, are neon tetras cold water fish?

By definition, cold water fish don’t require heaters in tanks. So, neon tetras aren’t classified as cold water fish because they can only thrive in warm water.

If you reside in a cold region, you’ll need to use a heater and continuously track the temperatures, ensuring they don’t fall below the vital range.

Neon tetras are true masterpieces in any aquarium. They’re admired for their glossy bodies, bright colors, and energetic swimming.

So, to keep that energy going, give them a warm welcome and make them feel at home.