Hi, I have read that oyster shells were good to put in soil. So I have purchased a few times the large bag of oyster shell, which I am to understand that this is the chicken grit that is actually what is used to add to soil mixes. I have added oyster shells to my potting mix and garden beds to help the clay soil drain better and easier to pull a weed out. I haven't found a problem with it, but have wondered if this is the "chicken grit" that the gardener was using for his soil as an additive. Also, I read in the UCDAVIS soil mix that someone linked to in Creating Soil, I think...use oyster shells to their soil mixes. So I guess I'm on the right path, but wondered about the salt factor that is on or in the oyster shell as helping or can cause a problem?