Red Eye Tetra Care Guide
The Red Eye Tetra (Moenkhausia sanctaefilomenae) is a hardy and active freshwater fish popular among UK aquarists. Known for its striking red eyes, silver body, and contrasting black-and-white tail markings, it is an attractive schooling fish that thrives in larger community aquariums.
In this guide, you'll learn everything you need to know about Red Eye Tetra care, including tank size, water conditions, compatibility, feeding, and typical UK prices - plus how to buy or sell them locally.
Quick facts about Red Eye Tetras
Red Eye Tetras are native to South America and inhabit rivers, streams, and floodplain waters throughout Brazil, Paraguay, Bolivia, and Argentina. They are highly adaptable fish and are known for their hardiness, making them a good choice for both beginners and experienced fishkeepers.
Their bright red eyes and distinctive tail pattern make them easy to identify in a community aquarium.
Moenkhausia sanctaefilomenae
5-7 cm
Brazil, Paraguay, Bolivia, and Argentina
75L (20gal)
5-8 years
Peaceful, active, schooling
22-28°C
Omnivore (flakes, pellets, frozen and live foods)
6.0-8.0
£2-£5 per fish
How Many Red Eye Tetras Should You Keep?
Red Eye Tetras are schooling fish and should always be kept in groups.
- A minimum group of 6-8 is recommended
- Groups of 10 or more encourage natural behaviour
- Larger shoals reduce stress and improve confidence
Keeping too few can lead to:
- Nervous behaviour
- Increased fin-nipping
- Reduced colouration
They are most active and attractive when maintained in sizeable groups.
Ideal Tank Conditions for Red Eye Tetras
Providing the right environment helps Red Eye Tetras remain healthy and display their best colours.
- Tank Setup: Community aquarium with open swimming areas
- Substrate: Sand or gravel substrate
- Plants & Decor: Hardy plants, driftwood, rocks, and shaded areas
- Water Conditions: Stable freshwater with good water quality
- Filtration & Flow: Gentle to moderate filtration
- Lighting: Moderate lighting
They are adaptable fish but still benefit from a mature, well-maintained aquarium.
Compatibility with Other Fish
Red Eye Tetras are generally peaceful but can be energetic and occasionally boisterous.
- Good Tankmates: black neon tetras, bloodfin tetras, Congo tetras, rainbowfish, corydoras catfish, pearl gouramis, and peaceful barbs
- Avoid: very slow-moving long-finned fish, aggressive cichlids, and tiny nano species
Occasional fin-nipping can occur if shoals are too small.
Are Red Eye Tetras Easy to Care For?
Red Eye Tetras are easy to care for and suitable for beginners.
They require:
- Stable water quality
- Appropriate shoal sizes
- Regular feeding
- Adequate swimming space
They are among the more forgiving tetra species available.
Red Eye Tetra Price in the UK
In the UK, Red Eye Tetras typically cost between £2-£5 per fish.
Prices vary depending on:
- Size and age
- Availability
- Shop vs hobbyist breeders
They are affordable and widely available.
Where to Buy Red Eye Tetras in the UK
Red Eye Tetras are available from most aquarium shops and tropical fish retailers.
Sourcing fish locally can:
- Reduce transport stress
- Allow you to inspect health and body condition
- Offer better value
TankMate UK helps connect fishkeepers who want to buy, sell, or rehome fish safely - without shipping.
Can You Sell Red Eye Tetras?
Yes - Red Eye Tetras are occasionally bred and sold by hobbyists.
Selling locally is often the best option, as it:
- Minimises stress for the fish
- Avoids the risks of shipping
- Connects you with local aquarists
TankMate UK allows you to list fish quickly and find local buyers.
Feeding Red Eye Tetras
Red Eye Tetras are omnivorous and enthusiastic feeders.
Key Tips
- Feed high-quality flakes or small pellets
- Supplement with frozen bloodworms, daphnia, and brine shrimp
- Offer occasional live foods
- Feed small portions 1-2 times daily
A varied diet supports healthy growth and vibrant colouration.
Common Problems with Red Eye Tetras
Fin-nipping, often caused by:
- Small shoal sizes
- Overcrowding
- Inappropriate tankmates
Faded colours, linked to:
- Stress
- Poor water quality
- Inadequate diet
Disease outbreaks, caused by:
- Poor maintenance
- Sudden parameter changes
- Introduction of unquarantined fish
Why Red Eye Tetras Are So Popular
- Distinctive bright red eyes
- Hardy and beginner-friendly
- Active schooling behaviour
- Adaptable to a range of water conditions
- Excellent community fish
When kept correctly, Red Eye Tetras create a lively and attractive display that works well in a wide variety of freshwater aquariums.
Frequently Asked Questions
No, they are generally peaceful, although they can occasionally nip fins if kept in groups that are too small.
At least 6-8, though larger shoals are strongly recommended.
Yes, they are hardy, adaptable, and relatively easy to care for.
At least 75 litres, with plenty of swimming space and a suitable shoal.
Looking to Buy or Sell Red Eye Tetras Locally?
TankMate UK connects fishkeepers who want to buy, sell, or rehome fish safely within their local area.
Whether you're adding an active school of tetras to your aquarium or looking to rehome fish responsibly, 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.