I know places like Starbucks sometimes have bins for bags of used coffee grounds that are free to anyone that wants them . That would be great if cafes, diners or restaurants could save egg shells as well. I never have questioned the use of egg shells because it seems like a good idea. Not that I've ever had my soil tested. I wonder how much calcium, etc is really released over time and if it would be detrimental to have too much. Hmmm - now I'm curious.
