The Koi Pond

Do Koi Ponds Need Heaters? Unpacking the Pros and Cons Koi is a popular ornamental fish species that can add life and color to any backyard pond. Despite being resilient and adaptable, koi require certain environmental conditions to thrive, the most important of which is temperature. Cold temperatures can slow down the metabolism of koi and affect their immune system, making them more susceptible to diseases. On the other hand, high temperatures can increase the oxygen demand in the pond and stress the fish, leading to lethargy, loss of appetite, and even death. … »