Krystal, "Shell Grit" may be what you guys call oyster shell. See if it lists the ingredients on the bag. It's probably the right stuff, but I'm a trust but verify kind of a guy.
The flock is good, but some are brats... I can show pics of them in the front yard if you like.
The flock is good, but some are brats... I can show pics of them in the front yard if you like.