Monarch Ultimate Block Salt is available in 8kg bags. Each bag contains 2 x 4kg blocks of Monarch Water Block Salt. Suitable for all Block Salt Water Softeners including the Monarch Plumbsoft Solo and Solo Ultra Non Electric Water Softeners. Why should you switch to Monarch Ultimate Block Salt Firstly, Monarch are so confident of its quality; they have put our name on it. Secondly, it s BS EN973 approved and great for fish and chips too! For optimum performance and efficiency your water softener requires periodically topping up with good quality food grade Tablet Salt. Made with special care for water softness, Monarch Salt tablets dissolve evenly, so there are no problems with undissolved salt building up in the base of your water softener. The salt blocks of sits into approximately 1 cm of water in the salt tank, dissolving slowly from the bottom. Once the salt drops to about a third of it’s size, another block can be placed on top, ensuring there is always some salt in the machine