Cardinal Tetra Care Guide
The cardinal tetra (Paracheirodon axelrodi) is one of the most popular tropical freshwater fish in the UK. Known for its vibrant red and blue colouring, it's a staple in planted and community aquariums.
In this guide, you'll learn everything you need to know about cardinal tetra care, including tank size, water conditions, compatibility, feeding, and typical UK prices - plus how to buy or sell them locally.
Quick facts about Cardinal Tetras
Cardinal tetras are small schooling fish native to the Amazon Basin. They are often compared to neon tetras but feature a longer red stripe running the full length of their body.
They are peaceful and best kept in groups, where their colours and behaviour really stand out.
Paracheirodon axelrodi
4-5 cm
Amazon Basin (Brazil, Venezuela, Colombia)
60-75L (15-20gal)
4-5 years
Peaceful, shoaling
24-28°C
Omnivore (flakes, micro pellets, frozen, live foods)
5.5-7.0
£2-£4 per fish
How Many Cardinal Tetras Should You Keep?
Cardinal tetras are shoaling fish and should always be kept in groups.
- Minimum group size of 6-10
- Larger groups of 15+ are ideal
- Bigger shoals create stronger schooling behaviour
Keeping too few can lead to:
- Stress and hiding
- Dull colouration
- Increased susceptibility to illness
In larger groups, they display beautiful, synchronised movement.
Ideal Tank Conditions for Cardinal Tetras
Providing the right environment helps cardinal tetras thrive and display their best colours.
- Tank Setup: Well-planted aquarium with open swimming space
- Substrate: Dark substrate enhances colour
- Plants & Decor: Dense planting, driftwood, and shaded areas
- Water Conditions: Soft, slightly acidic water preferred
- Filtration & Flow: Gentle flow with good filtration
- Lighting: Dim to moderate lighting mimics their natural habitat
Stable conditions are more important than exact parameters.
Compatibility with Other Fish
Cardinal tetras are peaceful and ideal for community aquariums.
- Good Tankmates: other small tetras, rasboras, corydoras catfish, dwarf cichlids, and small gouramis
- Avoid: large or aggressive fish, and species that may see them as food
Their small size means tankmates should be chosen carefully.
Are Cardinal Tetras Easy to Care For?
Cardinal tetras are moderately easy to care for and slightly more sensitive than some beginner fish.
They require:
- A stable, mature tank
- Good water quality
- A proper group size
- A varied diet
They are hardy once established but sensitive to sudden changes.
Cardinal Tetra Price in the UK
In the UK, cardinal tetras typically cost between £2-£4 per fish.
Prices vary depending on:
- Size and condition
- Availability
- Shop vs hobbyist sellers
They are widely available and affordable.
Where to Buy Cardinal Tetras in the UK
Cardinal tetras are widely available in UK aquarium shops and from private sellers.
Sourcing fish locally can:
- Reduce transport stress
- Improve survival rates
- Offer better value
TankMate UK helps connect fishkeepers who want to buy, sell, or rehome fish safely - without shipping.
Can You Sell Cardinal Tetras?
Yes - cardinal tetras are sometimes bred and sold by hobbyists, though breeding is more challenging than with some species.
Selling locally is often the best option, as it:
- Minimises stress for the fish
- Avoids the risks of shipping
- Connects you with responsible aquarists
TankMate UK allows you to list fish quickly and find local buyers.
Feeding Cardinal Tetras
Cardinal tetras are omnivorous and require a varied diet.
Key Tips:
- Feed high-quality flakes or micro pellets
- Supplement with frozen or live foods (e.g. daphnia, brine shrimp)
- Feed small amounts regularly
- Ensure food is small enough for their mouths
- A varied diet helps maintain their vibrant colours.
Common Problems with Cardinal Tetras
Fading colour, often caused by:
- Stress
- Poor water quality
- Inadequate diet
Sudden death after introduction, linked to:
- Poor acclimation
- Unstable tanks
Hiding behaviour, caused by:
- Too small a group
- Lack of cover
Why Cardinal Tetras Are So Popular
- Bright red and blue colouration
- Peaceful and community-friendly
- Ideal for planted aquariums
- Beautiful schooling behaviour
- Affordable and widely available
When kept correctly, cardinal tetras create a vibrant and dynamic display in any aquarium.
Frequently Asked Questions
Cardinal tetras have a longer red stripe running the full length of their body.
At least 6-10, though larger groups are recommended.
They can be, but are best in stable, established tanks.
At least 60-75 litres, with more space preferred for larger groups.
Looking to Buy or Sell Cardinal Tetras Locally?
TankMate UK connects fishkeepers who want to buy, sell, or rehome fish safely within their local area.
Whether you're stocking your aquarium or passing fish on to a new home, you can:
- Browse fish available near you
- List your own fish in minutes
- Avoid the risks of shipping
Explore local listings with TankMate UK and find the right fish for your aquarium.