I bought my spa in April 2013. The start-up package they gave me contained Silk Balance. Silk Balance is such a great time saver because it eliminates all the testing and having to mess with all the chemicals to get the spa water chemically balanced. A few ounces of Silk Balance once a week is all it needs to stay balanced. The chlorine and the shock oxidizer are harsh chemicals and are hard on your skin. Silk Balance softens the water so your skin feels good when your done using the spa Al Larsen