When you fill a hot tub for the first time, or when you refill it after draining it, you’ll use start-up chemicals to properly balance the pH and sanitize the water prior to use. This will help ensure a safe and comfortable soaking experience through correct pH levels, alkalinity, sanitizer levels and other factors that impact the quality of your water. For each brand of hot tubs that we carry, we offer different options of start-up chemical kits for you to choose from at checkout.