Love this product! After a lot of research on different products we decided to give SilkBalance a try. Are we glad we did! I didn’t use our hot tub a lot because of the chemical smell and the fact that I always had to take a shower afterwards. Now I finally enjoy using our hot tub. We shut our tub down for the winter, we live up north, because I was tired of always standing out in the cold fiddling around trying to get the tub balanced and trying to clean the biofilm off. Now with just 75 ml once a week we will be using our hot tub year round. We now have soft, crystal clear water with no chemical odour or biofilm! Thank you for such an awesome product!