White deposits inside Bosch dishwasher?

I've checked the filters, topped up the salt, topped up the rinse aid, used a dishwasher cleaner, checked and cleaned the spray bars... but I'm still getting streaky glasses and white smears on the inside of the dishwasher. Looks like the salt isn't getting into the wash water. I've poked around inside the salt reservoir, but that doesn't do anything either. Help!