If you want your Koi to love you, get them this KoiExerciser

Koi can lose their shape in a pond, developing large bellies. Since carp are a river fish rather than a pond fish they are happiest in an environment that can offer them some current to swim and play in.
Show koi especially need exercise to retain their shape, the first consideration of a koi judge is the shape of the koi.
The KoiExerciser comes complete with a 2 speed pump, exerciser manifold and timer.
Can be set to come on once or twice a day for exercise intervals. Koi will actually line up to swim against the current before the pump comes on after getting used to the KoiExerciser.
Each Eductor will add an additional 4 to 5 times the amount of water actually pumped through them.
Literally turns the pond into a river while it is on, the fish love it. KoiExerciser kit...pump, timer and 4 gang eductor.....949.95