Koi are cold-blooded and their metabolism is directly tied to water temperature. Feeding the wrong food at the wrong temperature is one of the most common mistakes in koi keeping.
Temperature-based feeding rules:
Below 50F (10C): Do not feed. Koi cannot digest food at this temperature. Undigested food can rot in their gut and cause illness.50-60F (10-15C): Feed wheat germ based food only, once every 2-3 days. Small amounts.60-70F (15-21C): Feed wheat germ or low-protein food, once daily.70-80F (21-27C): Feed high-protein growth food, 2-3 times daily. This is peak growing season.80-85F (27-29C): Reduce feeding. Dissolved oxygen is lower at high temps. Feed once daily.Above 85F (29C): Stop or drastically reduce feeding. Focus on aeration.General feeding guidelines:
Feed only what koi consume in 3-5 minutesRemove uneaten food to prevent water quality issuesVariety is good: supplement pellets with occasional treats like shrimp, lettuce, or watermelonNever feed bread, corn, or processed human foodTransitioning between seasons:
Spring: start feeding slowly as temperatures rise above 50F, begin with wheat germFall: transition to wheat germ as temperatures drop below 65F, stop feeding below 50F