Made naturally with sun, wind and time®. Our solar salt water softener crystals are a 99.6% pure and a natural choice for treating your hard water. It’s a great way to put nature to work softening your hard water. Diamond Crystal® Solar Naturals® Water Softener Salt Crystals have a white, opaque appearance and are recommended for use in all water softeners. Contain up to 99.6% pure salt Made naturally with sun, wind and time® Solar salt crystals are naturally white and opaque Low insoluble content Minimize accumulation tank residue Recommended for use in all water softeners