We purchased our hot tub about a year ago now. The sales staff convinced us to use Silk Balance and gave us the first bottle. Initially I thought it was just another sales ploy to purchase more expensive chemicals. Our best friends who have had a hot tub for many years have never used it. Since it was free I used it. It has made a world of difference. Sitting in our tub versus our friends who doesn’t use Silk Balance is like day and night. The water in ours is so much softer. Also don’t have the dryness on our skin from the chlorine. Even our suits don’t have near the chlorine smell. When our friends came over and used our hot tub they were amazed by the difference.