TIP: CHECK WATER SOFTENER and add salt when it’s low. Refill the tank to around two-thirds full.
You should be picky about the salt you choose, too. There are three basic types of water softener salt: rock, solar and evaporated. In general, look for higher purity salts, which will leave less storage tank residue. This reduces the chance you'll have a salt bridges or salt mushing, and will result in less maintenance. High-quality salts—and salts in pellet form—help eliminate bridging problems.
Rock salt is the least expensive, but it also contains higher levels of insoluble minerals or impurities. If you use this you could end up with a dirty, muddy tank. Plus, the efficiency will be affected and there will be impurities in your water.
Solar salt is much more soluble than rock salt. It is created from the evaporation of seawater and is found in both pellet and crystal form.
But the best option is evaporated salt which is obtained through a combination of mining and evaporation. This is the purest form of salt. Additionally, many leading brands also offer salt products that address specific issues, such as high iron concentration, rust stains and sodium alternatives.