about 1/2 ton of salt
I buy a yard of bulk salt at a time. Dumped into an open-top box made of a 4x8 3/4" plywood with 2x12 sides and two 4' dividers. Makes 3 sections that keep the weight behind the rear wheel after I empty the front section. Works great! I can pull it out to dump in a load of salt, then push it back under the camper shell to keep it dry.