Cardinal Tetra
Paracheirodon axelrodi
Also known as Red Neon
Edited by Ivan F. · Reviewed
Beginner verdict
Like a neon tetra with the red stripe running the full length of the body, this peaceful schooler glows in a soft, warm, planted tank. It handles warmer water than neons, which makes it a natural partner for rams and other warm-water community fish.
Care at a glance
- Min tank size
- 14 US gal
- Footprint
- 24 x 12 in
- Temperature
- 73–84 °F
- pH
- 3.5–7.5
- Hardness
- 1–12 dGH
- Swim zone
- Mid-Water
- Min group
- 8 fish
- Lifespan
- 4–5 years
Cardinal Tetra care mistakes to avoid
The mistakes beginners most often make with this species.
- Do not buy just one or two. Keep at least 8 fish so they feel secure.
- Do not add them to a brand new tank. Cardinals handle ammonia and nitrite poorly.
- Many are wild caught, so expect a delicate first few weeks and acclimate slowly.
- Avoid fish big enough to eat them, because a small cardinal fits in many larger mouths.
- Check your tank before you buy. Our sourced minimum is 14 US gallons.
Cardinal Tetra tank mates and swim zone
Mid-Water
Spends most of its time in this part of the tank.
Poecilia reticulata
Xiphophorus maculatus
Trichogaster chuna
Trichogaster lalius
Trichopodus leerii
Trichopsis pumila
Barbodes semifasciolatus
Their temperature ranges barely overlap, so you will have little room for error.
Betta splendens
Betta often does best alone. Only try this in a larger, planted tank, and watch closely.
Sewellia lineolata
Their temperature ranges barely overlap, so you will have little room for error.
Ancistrus cirrhosus
Bristlenose Pleco is much larger than Cardinal Tetra and may frighten or even eat it.
Tanichthys albonubes
Their temperature ranges do not overlap, so one of them would always be stressed.
Xiphophorus hellerii
Swordtail is big enough to eat or bully a fish as small as Cardinal Tetra.
Pseudomugil furcatus
One needs much harder water than the other can tolerate.
Compare
Cardinal Tetra feeding and care
How to feed
- Feed micro pellets or crushed flakes small enough for a tiny mouth.
- Add frozen daphnia or baby brine shrimp a few times a week.
- Feed small portions you can see finished within a couple of minutes, because overfeeding fouls the water fast.
Telling males from females
Mature females are noticeably rounder in the body and a little larger than males.
Plants that suit it
Species facts
- Family
- Characidae
- Native to
- Upper Orinoco and Negro rivers, South America
- Adult size
- 1.4 in (3.5 cm)
- Temperament
- Peaceful
- Social needs
- Schooling/Shoaling (6+)
- Diet
- Omnivore
- Water flow
- Gentle
- Substrate
- Any
- Live plants
- Yes - Loves Plants
- Shrimp
- Adult Shrimp Only
- Fin nipping
- None
- Vulnerable to nippers
- No
- Breeding
- Difficult in Home Tanks
Cardinal Tetra FAQ
What size tank do Cardinal Tetras need?
Our sourced minimum is 14 US gallons (54 liters), with a footprint of 60 x 30 cm. A bigger tank is always easier to keep stable.
How many Cardinal Tetras should I keep?
Keep at least 8 fish. Bigger groups usually look better and behave more confidently.
What can live with Cardinal Tetras?
Good matches on our list include Fancy Guppy, Platy and Honey Gourami. Avoid White Cloud Mountain Minnow and Endler's Livebearer.
How long do Cardinal Tetras live?
Care guides report about 4–5 years. Stable water and a good diet make the biggest difference.
What is the difference between a cardinal and a neon tetra?
On a cardinal the red stripe runs the whole length of the body, while on a neon it stops halfway. Cardinals also prefer warmer, softer water.
Where to buy Cardinal Tetra
Stores that list it under the same scientific name as this page. We earn nothing from these links. We have not bought from them, so check each store's own terms.
We have not found a store that sells Cardinal Tetra under its scientific name yet. We add stores as we confirm them.
Live animals and plants travel by courier. Check the store's live-arrival guarantee, and only buy once your tank has cycled (see how to cycle a fish tank).
Some US states restrict certain species. Check our US state aquarium rules table and your state's own rules before you buy.
Complete the tank
A forgiving setup with room for a small community.
Tank size for this species
At least 14 US gallons (54 L), 60 x 30 cm footprint
Filter
Hang-on-back or large sponge filter
Easy to maintain and strong enough for a community without blasting the fish.
We are still choosing products for this.
Heater
Adjustable heater, about 5 W per gallon: 100 W at 20 gallons, about 150 W at 29
Enough power to hold a stable temperature in most homes. Size up for a cold room.
We are still choosing products for this.
Water Conditioner
Dechlorinator such as Seachem Prime
Tap water contains chlorine or chloramine that harms fish.
Seachem Prime US
Fritz Complete Water Conditioner US
API Betta Water Conditioner US
sera aquatan Spain
Tetra AquaSafe Spain
Maker's page · Sold at Kiwoko · Sold at Tiendanimal · Sold at zooplus.es
Why we chose these (Best Water Conditioner for Betta Fish). Nobody here has used or tested them.
Test Kit
Liquid kit such as API Freshwater Master
Tracks ammonia, nitrite, nitrate and pH while the tank cycles.
API Freshwater Master Test Kit US
API General & Carbonate Hardness Test Kit US
Maker's page · Sold at The Shrimp Farm · Sold at Bulk Reef Supply
sera aqua-test box (Cl) Spain
JBL PROAQUATEST COMBISET Plus NH4 Spain
Why we chose these (Best Test Kit for a Freshwater Aquarium). Nobody here has used or tested them.
Cycle the tank before adding animals. See our guide on how to cycle a fish tank.