Wow! That is a lot of duck food, you can just not give them more food tomorrow until they eat it off the ground. In the long un though you could get a real feeder that is free choice, and you can pu a catch tray under it. I do this with a random lid for and old garbage can or a large plastic bin. But just something to catch the spilled food with. OR yo could get a feeder from the website Granpa's feeders! I love these! tHey are awesome! No spill, water proof, and rodent proof! They are on the expensive side for sure, but totally worth it! Oh and if yo buy a grandpa's feeder, it could take up to a mont plus to arrive because they are made in New Zealand, this depends on where you live, but don't be alarmed if you order it, an dit take a bit to arrive.