Rock Away

[dianer29]

My Silkies are 8 months old and I finished up the last of the parakeet grit I had been using for them. I purchased regular grit for them thru a poultry supplier. It is much bigger in grain size and I do not feel comfortable offering to them,as it is much bigger than what worked for them. They are not free to range .I cannot understand why the grit would be such a size difference ?
Input please. Mahola