Choose healthy, mature koi with strong body shape and clear fins
Use breeders that are at least 2 to 3 years old
Select one female and two or more males for better fertilization
Keep breeding fish in separate, clean conditioning tanks before spawning
Feed high-quality protein-rich food for several weeks before breeding
Maintain stable water quality with low ammonia and nitrite
Keep water temperature around 68 to 74°F
Provide spawning mats, brushes, or fine-leaved plants for egg laying
Introduce males and female into the breeding pond or tank at the right time
Watch for chasing and spawning activity early in the morning
Remove adults after spawning to prevent egg eating
Aerate the water gently to keep eggs oxygenated
Treat or remove unfertilized eggs to reduce fungus spread
Use antifungal treatment if needed and allowed
Keep eggs in clean, well-oxygenated water
Expect eggs to hatch in about 3 to 5 days depending on temperature
Feed fry infusoria or liquid fry food after yolk sacs are absorbed
Gradually switch fry to baby brine shrimp or finely crushed food
Separate fry by size as they grow to reduce cannibalism and competition
Cull weak, deformed, or unhealthy fry if breeding for quality koi
Maintain frequent water changes and filtration throughout growth
Avoid overcrowding in breeding and grow-out tanks
Keep detailed records of parent fish, spawning dates, and fry quality
Quarantine new fish before adding them to breeding stock
Monitor for disease, parasites, and stress throughout the process