There are a limited number of causes for mineral escaping the tank. Most common is a cracked/broken distributor tube or bottom basket; or a top basket if there is one. If that is the cause, you really need to find and fix it because if it gets worse your plumbing and appliances could become totally blocked. I suggest you call Culligan for service unless your tank has an industry standard 2.5" 8 thread er inch opening. If so you can DIY by buying a new distributor tube and replacing the old one.
Another cause is a leaking o-ring in the bottom of the control valve where the distributor tube goes up into the control valve.