Hi, we have inherited a water softener from the previous owners of our new property. It looks like they used the 4kg blocks and am wondering if there would be any issues using the tablet salt? The model we have says suitable for block or tablet but when the service guy came out he said block is better and tablet will mean it needs servicing more often but not sure if that's just sales speak as they prefer to sell the blocks as they are more expensive! Anyone with a water softener that can share their experience? Thanks