The JBL PROPOND SPRING+GROWTH clearly shows that the protein/fat ratio alone is not decisive. At 3:1 it is identical for the Spring food and the Autumn food, even though the food composition is completely different! Because spring and autumn have the same water temperatures, the recommended protein/fat ratio is 3:1, but the objectives of the food are very different - and thus its composition as well. 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. This is why the autumn food is designed to sink.