Autumn is the ideal time for fish to build up their energy reserves for the winter. If you still have summer food left over, you can first mix it with the autumn food and then phase it out. The same procedure can be followed for the transition to winter. At water temperatures below 10 °C, only extremely easily digestible winter food should be given. At 3:1 the protein/fat ratio in the food is identical in the spring and autumn foods, although the food composition is completely different! Because spring and autumn have the same water temperatures, the ideal protein/fat ratio is 3:1, but the foods have very different objectives - and therefore also different compositions. In spring, the fish need fittening and fattening up after the harsh winter, e.g. to defy spring viraemia. In autumn, on the other hand, the fish need to build up "winter fat" for the coming winter in order to survive it in good health. Added to this is the different sinking behaviour of the food. In spring, the fish become active again and can come to the surface to feed (an opportunity to observe whether disease is present). This is why the spring food floats. In autumn, on the other hand, the fish come to rest and need to feed on the bottom. The autumn food is therefore designed to sink.