Well, Tony, the pond is down to 73F, so the koi know its getting to be winter.

... This is when I get serious about forcing their bodies to think it is winter. With it being dark when I get home, this is the time of year when the koi get one feeding in the morning on weekdays... two feedings per day on weekends. The morning feed now includes 50% sinking wheatgerm (Hikari). The weekend feedings are floating pellets. The higher protein pellets are now diluted 50% by mixing in a staple pellet. By Thanksgiving only sinking wheatgerm and a staple pellet will be fed. By then temps will be in the mid-60sF. Volume of food will be cut by maybe a third at each feeding. Christmas Day is the last day they are fed until February. During January the water will edge a bit below 60F on the coldest days. Of course, the koi consume a lot of algae during these 3 months of reduced food. I can't really say this regimen does them good, but it may. I can say it does them no harm.