Koi will sleep, because koi and people, have their own unique biological clock. When Koi want to sleep, they will hide in the dark or lie motionless at the bottom of the tank. The general koi sleep time every day in four to five hours, if the nature is relatively lazy dragon and phoenix koi, sleep time is not the same as the general koi, usually sleep to six to seven hours.
Koi fish and people need to sleep, after observation, they come to the night, they will avoid to the fish tank behind the water plants and other dark static, this is the state of koi fish sleep. Koi living in fresh water basically like to hide behind reefs, water grass and other dark places to sleep. Because fish do not have eyelids like humans, koi fish do not have eyelids, so they do not close their eyes when sleeping.
Koi sleep can not have too much noise, will affect the rest of the Koi. Especially small koi, if often woken up, will affect the survival rate. Koi can not change water when sleeping, changing water will affect Koi sleep, should wait for Koi to wake up and then change water. Similarly, koi do not need to feed when they sleep, and they should wait for koi to wake up before feeding.
