Are Tetras Cold Water Fish

Tetras Cold Water Fish

If you have enough knowledge about tetras, you probably have little idea about their native climate. You may still be wondering, are tetras cold water fish?

Well, no, Tetras are not cold-water fish as they are native to the tropical climate, making themselves comfortable for warm water. And, cold water brings serious complications to your fish health and life-span.

Here is the answer to the series of your WH questions. The why, the how, the what are the constant question you keep wondering about your tetras and its water parameter.

Let us dive in to find answers to your queries and insecurities regarding tetras in cold water.

Are Tetras Cold Water Fish?

If you know the water condition of tetras’ natural habitat, then you know the obvious. No, Tetras are not cold-water fish; however, they can adjust to cold water for a while.

Tetras originally belong to Amazon Basin in South America, which is a tropical region with warm water streams.

Moreover, Tetras can adjust to a temperature slightly below the ideal mark, but the side effects start showing. They develop various diseases resulting in death eventually.

What Is The Ideal Temperature For Tetras In The Tank?

As you already know, tetras are tropical fish and demand an ideal temperature that mimics their natural habitat.

Their natural habitat has a temperature of around 80.6°F, making it a warm water environment. That’s why tetras prefer the temperature around this. Their ideal temperature ranges between 72°F to 80°F.

If you want your tetra tank to be beautiful, while you can ensure the safety of your tetras too, then it is wise to maintain the ideal temperature all the time.

I would suggest you use a heater for this purpose. I find AQQA Mini Submersible Aquarium Heater the best one in stock personally.

What Is Water Temperature Too Cold For Tetras?

Tetras fish are, as we know, healthy and happy in the temperature range between 72°F to 80°F. They can, however, adjust to the low temperature up to 70°F.

Any temperature range below this will bring unwanted chaos and health issues in the tetras. These tetras are delicate and sensitive when it comes to water temperature.

How Does Cold Water Affect Tetras?

Well, let’s begin with an example here. Imagine you are in the street with no sweater on a winter morning. How would you feel?

The answer is simple here: You, a warm-blooded human being, cannot handle the cold climate. You can’t handle temperature any higher as well. You demand a normal temperature that your body is adapted to.

The same thing goes with these tetra fish. They might adjust for a while, but once the cold water catches up with them, the result isn’t quite pleasant.

The change in temperature affects their metabolism and respiration. The cold water slows down their respiration and digestion, affecting their growth and activity.

Your tetra starts getting sleepy and sluggish as the result of cold water. A certain amount of stress is also something that builds up within them in the cold water.

Besides, the stress that follows the cold water is quite high for the tetra to handle, and all this eventually results in the death of your tetras.

Cold Water Borne Diseases In Tetras

The slight fluctuation in temperature invites many parasites and bacteria into your tetra tank. The most common case is with the Ich.

Ichthyophthirius multifiliis, commonly known as ICH, causes white spot disease in the warm water fish. Fish start showing small white spots in their skin after their exposure to this ICH.

ICH also feeds on the fins and gills of the fish and inflicts significant damages to them with a disease like Fin rot.

After prolonged exposure to cold water, tetras sometimes show diseases like mouth fungus and swim bladder disease as well.

How Can You Maintain Temperature For Tetras?

The necessity to maintain an appropriate water environment for tetras is unquestionably high.

The simple thing you can do is to put your tetra tank in a room with a temperature that mimics tropical climate.

The room temperature fluctuates time, and again, that’s why it is not an ideal way to maintain warm water for tetras. The heater at home cannot offer much help in the case of the aquarium.

The other thing you can do is, you can rely on aquarium lights to some extent. If the water temperature is slightly low than required, then these lights can maintain the heat in the tank water. I suggest Tetra Hidden LED Stick Light for Aquariums, Brilliant White, for lights in your tetra aquarium.

The next and the best thing you can do is get an aquarium heater for that tank. The heater will heat the water throughout the tank and keep up with the ideal temperature all the time.

The most necessary time to get a heater for tetras is winter. They can not deal with the cold, and the heater helps you to keep the water warm.

And in the case of temperate climates, the heater helps to maintain ideal temperature during summer.

Why Should You Use Heater In Your Tetra Tank?

The heater is the most important equipment your tetra tank need. It is simple and clear, while your fish swim freely, the heater maintains the heat without disturbing them.

Do Neon Tetras Need Heater For Survival? Find out here.

The heater will keep up with the ideal temperature throughout the day. Even in your absence, it works fine and reduces your stress about fish health and temperature maintenance.

Coldwater is some long-forgotten history when you have a heater in the tank.

Can Sunlight Help You Keep Tetras In Cold Water Tank?

No, absolutely not, you should never keep tetra tank direct to the sunlight. First thing first, avoid the direct sunlight and then find another way to maintain the water temperature.

Tetras neither prefers the sunlight nor handles cold water well. Both of these factors bring issues to the fish.

You may question about sunlight heating the tank and saving the cost of the heater. And you are right, direct sunlight makes the water warmer, but it makes the water, way hotter than it is necessary.

Another issue here is you’ll have no control over the sunlight and cannot manage the ideal temperature throughout the day.

And of course, the light that sunlight brings along with the heat. That light fuels the algal growth in the tank.

Tetras do well in the darker tank with few algae; however, the algal growth becomes limitless light resulting in chaos and crowd in the tank. This crowd and chaos make it difficult for tetras to live in.

Find out about “Do Tetra Fish Eat Algae? – Should You Add Algae To Their Diet?”

Frequently Asked Questions

Which Type Of Tetra Is Cold Water Fish?

Bloodfin tetra can be easily raised in a cold water tank.

Can You Mix Tetras?

Yes, you can mix tetras, but they, generally thrive in school with similar species. Find out more about Are Tetras Schooling Fish? – Easy Schooling Fish.

What Are The Best Cold Water Fish?

Paradise fish, dwarf crawfish, fancy goldfish, etc. are some best cold-water fish.

Which Tropical Fish Can Adjust In Cold Water?

Guppies, although is tropical fish, can adjust to cold water too.


In conclusion, it is clear that tetras are warm-water fish and thrives well when the ideal temperature is met. They develop diseases in cold water and dies eventually. Your fish should have a warm water aquarium, and a heater can help you with that. The heater maintains the ideal temperature and makes both you and your fish stress-free.

Related articles:

  1. How Many Tetra Fish Per Gallon of Water?
  2. How To Increase the pH of Your Freshwater Aquarium?
  3. Water Parameters for Tetra Fish: Stable Water Condition
  4. Can Tetra Fish Live Without Heater And Filter?
  5. Maintain Tetra Fish Tank Temperature Without Heater | Power Outage

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top