How to feed oster shell to ducks?

[JoshSnape]

I going to get some and i don't know if i need to buy another grit feeder.

 

[veronicasmom]

I just put ours in a rubber feed bowl in their shed to keep it dry. I don't mix it with their food, just leave it separate so they ones that need it eat it and my drake doesn't bother with it.

 

[tia]

Do most people use a different grit dish... I sprinkle some on their food but was wondering if I was using the correct amount.