SERUM watercare products are designed to work as a complete watercare system. It is designed to totally clean your hot tub pipes and plumbing and keeps the water clean, safe and worry free for up to 6 months! Hot tub SERUM is a two-step watercare system that is more efficient and more effective than anything in the marketplace today. Hot tub SERUM Total Clean System does four tasks--it's a purge product, surface cleaner, filter cleaner and a 6 month maintenance product! Hot tub SERUM watercare has been proven to be more effective than other leading watercare products and improve your hot tub's performance and water quality over time!