The amount of salt that you need to top up your water softener will depend on the model of the softener you have , how much water your household uses and the hardness of the mains water in your area. You can also confirm the compatibility of your water softener and the salt required by reading our Water Softener Salt Compatibility Chart. Once you’ve been using your water softener for a while, you’ll get a good idea of your household usage rate and how frequently you need to buy more salt . Our tablet salt is made by pressing fine, PDV food-grade salt under precisely controlled conditions to achieve high purity and consistency. As with all our salt, it is sourced from trusted suppliers, manufactured to the highest quality and delivered to your door in just a few days.