I looked at two online sources for food grade DE and the product itself wasn't too costly but the shipping was almost equal, and in the case of smaller quantities more than the product. That eliminates ordering online for me. So now I need to find a source within driving distance. I found out that the Earl May Garden store 30 mi away has it in 4# bags for around $13, but the person I talked to had no idea as to it's being food grade or not. My guess is that being in the garden store it IS food grade. I may drive the 30 mi to find out. I was surprised the big health food store in Lawrence doesn't carry it, but I ws told they use it i n their storage areas for insects but don't sell it in the store. I continue my search.