Cardinal Tetra - Paracheirodon axelrodi

Updated August 5, 2019
Author: Mike - FishLore Admin
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The Cardinal Tetra looks very similar and is often confused with the Neon Tetra. The Cardinal Tetra will have the red stripe the full length of its body on the lower half, whereas the Neon Tetra will have the red stripe only half way. These tetras make excellent community tank mates and for best results you should keep them in a school (shoal) of 6 or more.

Paracheirodon axelrodi School of Paracheirodon axelrodi

They prefer water slightly on the acidic side and for best results you'll want to acclimate them very slowly to your tank. Slowly mix in a little water from your tank to the bag they came in over a period of an hour or more. They can be very sensitive to dramatic changes in water chemistry (especially pH). Though these Cardinal Tetras should fare well if properly acclimated, this is not the fish to add to a new aquarium. Make sure that your tank has completed the aquarium nitrogen cycle. Give them a tank with low light levels and lots of aquarium plants.

It can be difficult to differentiate the male from the female but there is speculation that the females are a little bit larger than the male.

They will accept all sorts of tropical fish food, including flakes, frozen and freeze dried foods and definitley live foods.

Shoal of Cardinal Tetras Paracheirodon axelrodi Paracheirodon axelrodi Paracheirodon axelrodi

Cardinal Tetra Care

Scientific Name : Paracheirodon axelrodi

Common Names : Cardinal Tetra

Care Level : Easy, acclimate slowly to your tank water and don't even think about adding them to an aquarium that has not completed the aquarium nitrogen cycle.

Size : Up to 2 inches (5 cm)

pH : 5.5 - 7, prefer water slightly on the acidic side

Temperature : 73°F - 80°F (23°C - 27°C)

Water Hardness : 2° to 6° dH

Lifespan : 2 - 5 years

Origin / Habitat : South America

Temperament / Behavior : This is a very peaceful tropical fish and best kept in schools of 6 or more.

Breeding : They can be difficult to breed in the home aquarium. They are egglayers and the adult fish must be removed after dropping the eggs. Provide low lighting and very soft water (1° to 3° dH). Feed the fry brine shrimp.

Aquarium Size : 10 gallon or larger.

Tank Mates : Many, given their peaceful nature. Avoid keeping with tropical fish large enough to eat them.

Disease : Freshwater Fish Disease

Diet / Foods : Will go after flakes, live and freeze dried foods. Give them a varied diet for best results.

Tank Region : Mostly middle to top.

Gender : The male is usually smaller than a female of the same age.

Photo Credit : Photos copyright

Site References :

Paracheirodon axelrodi School of Cardinal Tetras

Cardinal Tetra Comments

From: Chris
These little cardinal tetras school with more or less any other similar size schooling fish.

From: Andy
Cardinal Tetras are beautiful, and they often get a bad rap because they are sensitive, some say more so than neons. But, I've had 4 cardinals that I quarantined for 2 weeks upon purchase and transferred to my well-planted tank (which actually has a higher pH than preferred) and they're doing well. Again, better than the six or so neons I have. I love them and will probably get more in the future.

From: Lauren
I have 5 neon tetras and they are doing well in my 16 gallon tank along with my clown loach, bala shark and 2 guppys. My question is: Is the Cardinal Tetra easier to keep than neons?
These tetras do seem to be hardier than the neon tetras. BUT - you have a much bigger problem here. The clown loach and the bala shark get way to large for a 16 gallon tank. Please get a much larger aquarium or return these fish to the store for a refund or credit. Also, please, please, please read up on (research) the fish you would like to keep before purchasing.

From: Marian
Hello, I just started my fish tank about a month ago with two Cardinal tetras. I would like to add 2 or 3 more fish for a total of 4 to 5 small schooling fish because I don't want to overcrowd my 20 gallon fish tank. What other fish school with Cardinals? Or should I just get cardinals? I would like to get a couple other types for variety. Which would be the best and is this a good enough number of fish for a 20 gallon tank? Thanks!
I think that having a school of cardinals like this in an aquarium stocked with live plants would make a great small fish tank setup. The colors on the cardinals are fantastic and couple that with the greenery from the live aquarium plants and you'll have a nice looking and well functioning aquarium.

From: Dean
I have 25 of these guys in my 400 litre tank with many other fish. They get on great with the others and they dont tend to school as much though.

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