“Winter“ is not the same all over the world. In some countries it’s still 30°C like in summer, but with more rain.
In northern countries the winter starts in September and in Central Europe the winter can be free of snow or can pass with temperatures barely dropping below zero.
At temperatures below 10 °C pond fish mostly retreat into the deeper water layers to slowly come to a rest. Nevertheless it often happens that fish remain active at surface temperatures between 5 and 15 °C (where most measurements are carried out). Activity means energy demand, and this energy needs to be supplied with adequate food. Otherwise the fish have to live from their energy reserves. Unfortunately many pond owners experience that by spring the fish are so weakened from the winter period that they have become very susceptible to illnesses. Spring viraemia is a dreaded phenomenon. Only when the fish cease their activities and more or less lie on the pond ground does their need for food stop completely.
With the right winter food you can prevent problems very efficiently. As long as the animals are still active and feeding, JBL ProPond Winter will supply them with more energy than they need to metabolize the food at temperatures between 5 and 15 °C. Other food ranges may contain an energy content which is below the energy needed for their metabolism. Then the fish will be starving while they eat. Fish oil, salmon, and shrimps along with wheat and corn in the JBL ProPond food provide the scientifically required protein/fat ratio of 2:1.
If you invest in the right winter food you’ll have healthy fish in spring and save money and trouble too.