We've added salt, doesn't seem to be doing anything

We've just moved into a house with a water softener. For the first three months, we've had good water, and I noticed last week that it wasn't slimy any longer. We added salt to our water softener, and my husband ran it through a cycle(?), but the water hasn't changed. Did we do something wrong? It's a Culligan, but I don't really want to call them -- they want $145 for a service call that may not be necessary.