Asagi Koi Care Guide
The Asagi koi is one of the oldest and most recognisable koi varieties in the UK. Known for its blue-grey netted pattern and contrasting red or orange markings, it's a favourite among pond keepers.
In this guide, you'll learn everything you need to know about Asagi koi care, including pond size, water conditions, feeding, compatibility, and typical UK prices - plus how to buy or sell them locally.
Quick facts about Asagi Koi
Asagi koi are ornamental carp bred for outdoor ponds. They are known for their distinctive reticulated (net-like) pattern along the back and red/orange colouring on the sides, fins, and cheeks.
They are hardy, long-lived fish that grow large and require proper pond conditions.
Cyprinus carpio
60-90 cm (can grow larger in ideal conditions)
Japan (developed from common carp)
1,000L+ (larger strongly recommended)
20-30+ years
Peaceful, social
4-28°C (coldwater species)
Omnivore (pellets, vegetables, natural pond foods)
6.5-8.0
£20-£200+ depending on size and quality
How Many Asagi Koi Should You Keep?
Koi are social fish and should be kept in groups.
- Minimum of 2-3 koi, though more is ideal
- Stocking depends on pond size and filtration
- Allow plenty of space per fish due to their large adult size
Overstocking can lead to:
- Poor water quality
- Stunted growth
- Increased disease risk
A well-sized pond is essential for keeping koi successfully.
Ideal Pond Conditions for Asagi Koi
Creating the right pond environment is key to maintaining healthy, vibrant koi.
- Pond Size: Larger ponds (2,000L+) are strongly recommended for long-term care
- Depth: At least 1-1.5 metres to protect from temperature swings and predators
- Filtration: Strong mechanical and biological filtration is essential
- Water Conditions: Stable, clean water with good oxygenation
- Plants & Features: Marginal plants and shaded areas help reduce stress
- Aeration: Air pumps or waterfalls improve oxygen levels
Regular maintenance is critical for koi health.
Compatibility with Other Fish
Asagi koi are peaceful and can be kept with other pond fish.
- Good Tankmates: other koi varieties, goldfish, and other peaceful coldwater species
- Avoid: very small fish that may be outcompeted for food
Koi are active feeders and may disturb plants while foraging.
Are Asagi Koi Easy to Care For?
Asagi koi are moderately easy to care for but require proper pond setup and ongoing maintenance.
They require:
- Large, well-filtered ponds
- Regular water testing and maintenance
- High-quality diet
- Long-term commitment due to lifespan
They are not suitable for small tanks or beginner setups without preparation.
Asagi Koi Price in the UK
In the UK, Asagi koi typically cost between £20-£200+, depending on size, age, and quality. High-grade specimens from specialist breeders can cost significantly more.
Prices vary depending on:
- Size and age
- Colour quality and pattern
- Breeder and origin (e.g. Japanese imports)
Buying locally can reduce stress and transport risks.
Where to Buy Asagi Koi in the UK
Asagi koi are available from specialist koi dealers and pond suppliers across the UK, as well as from private hobbyists.
Sourcing koi locally can:
- Reduce transport stress
- Allow you to inspect fish before buying
- Offer better value
TankMate UK helps connect pond keepers who want to buy, sell, or rehome fish safely - without shipping.
Can You Sell Asagi Koi?
Yes - koi are commonly sold or rehomed by pond keepers.
Selling locally is often the best option, as it:
- Minimises stress for the fish
- Avoids the risks of transport
- Connects you with knowledgeable buyers
TankMate UK allows you to list koi quickly and find local buyers.
Feeding Asagi Koi
Asagi koi are omnivorous and require a balanced diet.
Key Tips:
- Feed high-quality koi pellets as a staple
- Supplement with vegetables (e.g. peas, lettuce)
- Adjust feeding based on water temperature
- Avoid overfeeding to maintain water quality
Feeding should be reduced or stopped in very cold conditions.
Common Problems with Asagi Koi
Poor colour development, often caused by:
- Poor diet
- Suboptimal water quality
Stunted growth, linked to:
- Small pond size
- Overcrowding
Water quality issues, leading to:
- Illness
- Stress
Why Asagi Koi Are So Popular
- Classic and historic koi variety
- Distinctive blue net pattern with red highlights
- Hardy and adaptable
- Long lifespan
- Striking addition to any pond
When kept correctly, Asagi koi become a long-term, visually stunning feature of outdoor ponds.
Frequently Asked Questions
They typically grow to 60-90 cm, sometimes larger in ideal conditions.
Yes, they can coexist with goldfish in suitable pond conditions.
No, they are coldwater fish and can tolerate seasonal temperature changes.
At least 1,000 litres, though much larger ponds are strongly recommended.
Looking to Buy or Sell Asagi Koi Locally?
TankMate UK connects pond keepers who want to buy, sell, or rehome fish safely within their local area.
Whether you're stocking your pond 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 transport