Koi are majestic pond fish known for being great companion pets. On average they live 20-30 years, but if given a large natural environment they have been reported to live over 200 years reaching lengths of over 4ft. Koi are cold water fish and can withstand temperatures from 35-85 degrees, but they will be the most comfortable and active in 65-75 degree water. We recommend providing adequate filtration and at least 10 gallons of water per inch of Koi. Koi are not picky when it comes to eating and will love a mixed diet of high protein flake, pellet, frozen/freeze dried foods, and blanched vegetables.