Try feeding when water temps. are warmer and the fish are more active. If the water temp. dips into the 50's at night, avoid late afternoon/evening feedings.
Start feeding everyother day or so gradually going towards 2-3 times per week. Eventually once a week and then none at all if temps. dip below 50 for the winter. You don't want the Koi and goldfish swimming around w/full bellies. That undigested food in the intestines is what leads to health problems, as well as water quality issues if they stop feeding all together and the food goes uneaten. I am sure there is enough "stuff" for the fish to graze on during off days.
The cat may need to be direct fed a little more until the temps. get really, consitantly cold. Again, error on less than more food for him as his metabolism is also going to slow down a lot too.
