I am trying to stock up on rock salt for the spring but believe it or not I am having trouble finding it. No problem finding grass seed or BBQs though! Go figure. Anyway, I did manage to find rock salt made from Halite. If I recall from Geology, Halite is salt. Is it OK for ponds? Also, what about one that says the rock salt was processed from the red sea. The word processed made be wonder if chemicals were added. Any advice?