I don't know what quantity you're using at a time, but if you're wanting finer particles you can buy oyster shell meant for cage birds like finches and it's much smaller.Yikes. I just reordered shell from Amazon. The one they sell used to be little flakes about 1/8 inch diameter or so. This new bag has big flakes about 1/4 inch in diameter. You can't hide 1/4 inch pieces in their feed and expect them to eat it. They just pick around it. They do the same thing with the white rocks. I'm going back to using coral sand.