Can I Keep 1 Cardinal Tetra? – What You Need To Know

Fishkeeping is quite a widespread practice that has been around for a long time. Keeping fish is a great way to relax, and it also provides unique experiences that you can’t find anywhere else. While some owners find keeping a lot of fishes stressful, others enjoy having color and varieties in their aquarium. Mostly, fish can live alone, but they are better of with company. So, do you think it is better to keep just 1 Cardinal tetra?

Cardinal tetras are schooling fish, meaning you should always keep them in groups of at least six. It will ensure that the fish feel comfortable enough to school together and maintain their best colors throughout their lives.

Cardinal tetras have many benefits, including low maintenance and the ability to tolerate water conditions better than other species of tropical fish. However, most aqua experts do not recommend keeping just 1 cardinal tetra in your aquarium.

This article will explore the various aspects you need to know about before deciding whether or not you can keep just one – or any number!

Can I Keep 1 Cardinal Tetra?

Cardinal tetras are fascinating fish. They have unique red color and can grow up to four inches in length. However, they don’t do well on their own. So, you should only consider keeping them if you’re planning on having at least five of them together in the tank.

Moreover, Cardinal tetras are social and need the company of their species. Therefore, the schooling behavior of cardinal tetras is essential. They feel more secure and comfortable when they are in a group, especially with their species.

The best thing you can do for your cardinals is to give them the big tank possible (at least 55 gallons) and make sure that it has plenty of hiding places where they don’t have to see each other. Even if you keep cardinals in a smaller tank, they will not be as happy, and their color will suffer.

What Must Be The Minimum Number Of Cardinal Tetras In Your Tank?

Being a schooling fish, you need to ensure that you have enough cardinal tetras in your fish tank. The minimum number of Cardinal tetras that you must have in your fish tank is around six.

If you have the minimum number of cardinal tetras, they will form a school and swim together in your aquarium. This way, it becomes easy for them to hide if any danger approaches their territory or find food when scarce resources are available in the water column.

However, it doesn’t mean that the number of cardinal tetras in your tank should be only six. You can add more than five if you want, and they will still form a school with ease.

And finally, we would suggest not keeping solitary Cardinal tetra fish in an aquarium because they become too stressed without company, which could lead to their early demise.

Why Is Keeping Just 1 Cardinal Tetra A Bad Idea?

As explained earlier, Cardinal tetras are schooling fish that enjoys the company of their kind. But, keeping just one fish in the tank can be pretty depressing and stressful for this fish. Some of the reasons why you should never keep Cardinal tetras alone are:

  • The fish gets lonely and stressed.
  • They require a larger school size to keep them healthy and happy. It means that they need at least five other cardinal tetras in their tank.
  • Keeping just one Cardinal Tetra will cause stress because of the lack of company; this may lead to illness, injury, or even death.
  • A single Cardinal Tetra will not be able to enjoy the tank and its accessories fully.
  • Cardinal tetras are beautiful fish, but you can get a greater variety of colors when they live in schools. Your school should consist of at least five cardinal tetras for optimal coloration. Some examples include Blue (turquoise) metallic, black (dark), blue metallic, and purple.

So, if you are looking to keep one of these beautiful fish at home, I suggest that your purchase cardinal tetras in more significant numbers so the school can stay healthy and vibrant.

How To Choose The Ideal Tank Size For Your Cardinal Tetras?

Cardinal Tetras, a beautiful freshwater fish that comes from South America. They are peaceful and will be the perfect addition to any community tank as long as they have plenty of open space to swim around in, which is why you need at least 20 gallons tank is better.

These fish are a joy to watch and will add sparkle to any aquarium. They have an iridescent red body with a blue line that runs from the gills up through their eye! While they may not be as common in pet stores as other freshwater fish, they’re worth looking out for if you’re an aquarium hobbyist.

You can also see Cardinal tetras in groups of up to 20 or more. Thankfully, they are peaceful enough that they shouldn’t cause any problems with other tankmates. The only thing that you should make sure of is plenty of space for them all to swim around freely. Thus, it means the bigger your tank size is, always better.

What Are The Tankmates For Cardinal Tetras?

In their natural habitat, cardinal tetras live in groups of up to 100 individuals. So it is best to keep them together as a school. In addition, they often connect well with other small fish that belong to the same family Characidae. However, some of the fish that can be excellent tankmates for Cardinal tetras are:


These fish are very active and have a peaceful nature which makes them excellent tankmates for Cardinal Tetras. Also, they can grow up to eight inches, so it is best to combine these two species in a larger tank of at least 30 gallons capacity. In addition, guppies come from the same family as cardinal tetras and belong to the same genus.

Ember Tetra

These fish are very peaceful and do not grow over four inches, making them excellent tankmates for cardinal tetra. These fish are also great tankmates for Cardinal Tetras as long as you have a large enough aquarium to keep them all in.

In addition, ember tetras come from the same family Characidae, which means keeping these two species together.

White Cloud Mountain Minnows

These fish are popular as white cloud minnows. They can grow up to two inches which makes them good tankmates for cardinal tetras. Just make sure that you have a large enough aquarium of at least 30 gallons capacity. In addition, these fishes come from the same family (Cyprinidae) but from different genera, which means that they can live together.

However, you should avoid keeping white cloud minnows with goldfish because these two species have a very similar diet, and it would be hard for each of them to find their food in the same tank.


In conclusion, cardinal tetras are usually peaceful. Thus, you can keep them with most small community fish species.

However, you should avoid keeping them together with neon tetra, rummy nose tetra, etc., since they are very aggressive towards other fishes. Besides this, these two species also have similar temperaments as cardinal tetras. So, they will probably fight each other for dominance.

On the other hand, you should also avoid putting goldfish into the same tank with cardinal tetras. These two species have similar diets and live in the same water conditions. So, they might be competitive.

Thank you and happy fish keeping!

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