The success of commercially prepared feed or its equivalent is measured by how much increased weight of fish is produced by what weight of feed (FCR = feed conversion ratio). This means the weight of feed added to the pond whether the fish eats it or not because you have still paid for it in either case. Sinking feed often goes right to the bottom before the fish can eat it and then they can't find it. This is a subsurface feeding platform so that the feed can always be found by the fish when it is placed on it. The fish learn very quickly where to find the food, so this improves the FCR over what it would be without the platform.