A common issue with water softener salt tanks is called bridging in the salt tank. Bridging is usually discovered when a homeowner realizes that they are probably not getting soft water because their showers feel hard, or they have some lime deposits on their fixtures. To be sure your salt tank is not bridging simply open the lid of your salt tank and check to see that the salt is reaching the bottom of the tank, sometimes the tank looks full but it is actually hollow at the bottom.  If the salt looks all stuck together, gently take a broom handle (or a blunt object) and carefully, as not to puncture the sides of the tank break up the salt. This is common in areas like Tampa where the humidity is high several months out of the year, and is easily remedied.