Koi Carp for sale in the Netherlands

Koi carp: behaviour and suitability

Koi quickly learn where food appears and swim in a loose group. Their strength, digging and food competition make them unsuitable for small ornamental ponds or fragile small fish. Always assess the actual animal and, when a trade label covers several species, verify the scientific name before acquisition. Age, sex, health and previous housing can noticeably influence behaviour.

Care and housing

Use an outdoor pond at least 1.5 metres deep with clear flowing water and effective mechanical and biological filtration. Measure oxygen, hardness, pH, ammonia and nitrite. 15–25 °C is the preferred temperature range. Set up the complete enclosure before the animal arrives and record relevant values and daily behaviour. A sudden change in appetite, activity, breathing, posture or droppings calls for a check of the environment and, where needed, knowledgeable help.

Health and responsible acquisition

Buy active koi with close-fitting scales, intact fins and a normal appetite. Isolation, lethargy, reduced appetite or surface gasping are warning signs. Ask about quarantine and testing for contagious, fatal KHV. Ask the seller about age, origin, current care and known health problems, and ensure any documents belong to the animal offered. Never choose on colour, size or price alone, and identify a knowledgeable veterinarian or other species expert before urgent problems arise.