Somat Water Softener Salt for water softening in dishwashers. Somat Special Salt is for water softening in dishwashers. Tap water often contains lime. So that lime is not deposited on dishes and the dishwasher, some dishwashers have a water softening unit which withdraws the harmful lime from the water. Table salt is unsuitable for water softening in dishwashers. It may contain insoluble components affecting the efficiency of the water softening unit. Pictures and images are for illustration purposes only. Case of 8 boxes.