I stopped feeding for about one month this summer beacause the fish disappeared following some suspected heavy heron raids, my pond is WELL planted and must be crawling with insect life and natural food because a there were no emaciated fish when they finally emerged. I guess there is anywhere between 70 and 150 goldfish in 1450 UK gallon. My heavt crop of blanket weed also disappeared during the nonfeeding month and I have concuded from that that the undigested food was fertiliser for the BW. My fish LOVE live food like mosquito larvae and I have some water barrels set up to grow them but it has been a poor crop this year. In previous years I have been able to feed the fish for one month on live food, the big advantage is that live food doesnt promote BW growth.