Cardinal Tetras Diet: Feeding Tips and Compatibility

Cardinal tetra is a popular fish among aquarium enthusiasts. Cardinal tetras are hardy, active, and relatively inexpensive to purchase. These fish can undoubtedly tempt most fish keeping to take them home due to their enticing appearance. But you should know about the diet and aquarium setup of Cardinal tetras first before getting them.

Cardinal tetras’ diet can vary depending on the age and their activity level. Cardinal tetras are omnivores and will eat most types of food that you feed them. However, they do prefer live foods such as brine shrimp or bloodworms over flakes or pellets.

But there are some general guidelines that you should follow to provide them with an optimal diet. This article will go over the Cardinal tetras diet with feeding tips and compatibility with other species of fish.

Cardinal Tetras Diet

Tetras are omnivores and can do well on a varied diet. So, Cardinal tetras mostly eat insect larvae, insects, invertebrates like worms or snails, small crustaceans like copepods, and other zooplankton in the water. You can also supplement their diet with a flake or pellet food.

One of the most exciting things about these fish is that they will enjoy eating home-prepared food, making them great fish to keep in an aquarium with a homemade tank setup. When it comes to fresh vegetables, they will enjoy small zucchini, spinach, and lettuce.

In terms of commercial foods, they will enjoy most types of flake or pellet type food and frozen foods such as brine shrimp and bloodworms. There are also some aquarium foods with all the nutrients for your fish that you can prepare at home.

Seafood can also be a great addition to their diet as well. Most types of frozen seafood will work perfectly fine in the aquarium- thaw it out first before feeding it to your Cardinal Tetras. You can also provide them include shrimp/prawns, small pieces of fish fillet, like Tilapia or Cod (make sure there are no bones).

How Often Should You Feed Cardinal Tetras?

Cardinal tetras are not voracious eaters, but they do need a lot of food to survive. In the wild, you will find that these fish eat small insects and animals when there is nothing else available for them. It means that when it comes time to feed your Cardinal tetra tank mates, you should be careful not to overfeed or underfeed them.

Ignorance while feeding may result in a lack of nutrients or a build-up of toxins, leading to sickness and disease. So, when it comes time for your Cardinal tetra to eat, you should feed them as much food as they need to survive. Otherwise, the tank will become polluted quickly.

However, most aquarists prefer to feed Cardinal tetras at least twice a day. Also, make sure to remove any leftovers after twenty minutes. Usually, the best feeding time for Cardinal tetras is in the morning and at night because it fuels them to swim throughout the day.

What Foods Should You Feed Your Cardinal Tetras?

Feeding cardinal tetras are not tricky at all. You can also feed them through regular aquarium feeders. However, the cardinal tetra’s diet is not only about how often you feed them. You also need to know what kind of food they like and how much of it should be provided in every feeding session if you want your fish to stay healthy.

Some Of the foods best for Cardinal tetras are:

Live Foods

Live foods, such as brine shrimp and daphnia, are a good option for your Cardinal Tetras. However, some aquarists prefer to use freeze-dried varieties of food instead because they believe that it is easier to offer than live ones.

Regardless of the kind you choose, feeding them with these two options will surely provide them with the necessary nutrients they need to keep healthy.

Vegetable Foods

You can also feed your cardinals with vegetables such as zucchini, lettuce leaves, and spinach. However, only choose the ones that are safe for fish. Some of these veggies will undoubtedly negatively affect their health if fed too much or wrongly.

For example, feeding them with lettuce leaves will surely make your fish sick. It is because lettuce has a lot of lactucarium and can affect Cardinal tetras’ digestive system. It is the same reason why you should not feed them with cucumber as well.

Commercial Foods

In addition to these options, you can also provide your cardinals with some commercial food pellets and flakes instead of living or vegetable foods. Just make sure to read the label first before buying some because some food pellets contain too many fillers, which are not suitable for your fish.

Do Cardinal Tetras Eat Algae?

Cardinal Tetras eat algae. But they do not prefer whether the food source is of plant or animal origin. They will also feed on small insects and crustaceans in their natural habitat.

So if you are keeping them as pets, it would be wise to add some live foods into their diet regime from time to time. It can include brine shrimp, mosquito larvae, and fruit flies.

How Long Will Cardinal Tetras Survive Without Food?

Cardinal tetras can survive without food for around 10 to 14 days. If you plan on going out of town and leaving the fish alone in the tank, then it would be good to leave them some freeze-dried bloodworms or brine shrimp as these will not decompose if left for several weeks.

Is Automatic Feeder A Good Option To Feed Cardinal Tetras When You Go On Vacation?

An automatic fish feeder is an excellent option to keep the Cardinal tetras fed even when you are on vacation. You can program this device as per your wish. Thus, it will dispense food at regular intervals that you have set before going out of town.

What Are The Things To Consider When You Choose Cardinal Tetras Diet?

Firstly, choose the right food for your fish. It is better to get a variety of foods and feed them in small portions throughout the day than getting one type of pellet and feeding it all at once. Some brands provide you with different kinds of fish food pellets so that you can mix or match according to what works best for your fish.

Secondly, choose the right pellet size that best fits your pet’s mouth. Be sure that Cardinal tetras can swallow it easily without any difficulty. Their diet should fit into their mouths so they can eat them comfortably. If you’re not too sure which one will work well with your fish, then try some of the smaller-sized pellets and see how they react to them.

Lastly, mix and match your fish’s diet with some vegetables or other types of food. It will not only give them a little variety but also help maintain their overall health. For example, if you plan to feed your Cardinal Tetras pellet foods, consider adding some frozen or fresh brine shrimp to the diet.

Frozen foods are also great for your tetras, but you have to make sure that they can eat them without getting any issues with defrosting the food first before feeding it to them.

Some FAQs

What Is The Best Cardinal Tetra Tank Size?

The best tank size for cardinal tetras should be at least 20 gallons. But if you plan on keeping more than one pair of these fish in the same tank, you will need to have at least 30 gallons.

The larger the cardinal tetra tank size is, the better it will be for your fish. It is because they can swim around more freely. Also, there is less chance of stress when they have enough room to move around.

What Are The Fishes Compatible With Cardinal Tetras?

Cardinal tetras are very peaceful fish, and they do not bother other tank mates. They also get along well with most of the community fishes. So you can put them together in a large group. Just make sure that the group members have similar water conditions to avoid any issues between different species.

Some of the ideal tankmates for Cardinal tetras are:

  • White Cloud Mountain Minnows
  • Harlequin Rasboras
  • Ember Tetras
  • Glow Light Tetra, and many more


In conclusion, Cardinal Tetras’ diet should consist of a variety of foods. You can feed them in small portions throughout the day. You can feed them with live or frozen food. But make sure that the food you give is easily digestible.

Feeding these fish is not too difficult as long as you know what types of food will work best for your fish.

Hopefully, this blog post gave you a good idea about the Cardinal tetras diet. I have answered all your questions regarding what to feed them. Happy Feeding Your Cardinals!

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