That the exact same water softener I have used for many years. It takes 2 pounds of common table salt to recharge.
Water Softener linkI usually recharge once a month but you can tell the water is just a bit less soft by the end of the month (we are in TX a lot) but I am too lazy to do it every couple of weeks. When you first install one you may find that some of your spigots/shower head may clog as the calcium in your lines/heater are dissolved and break loose. It's all worth it though as the soft water feel great and keeps your plumbing clear of all that build up.
However, if you have any issues with too much salt in your diet the water softener do add a small amount of salt to all water used in your coach including cooking and drinking.