After many years working in the water chemistry field, this author still gets the same question: What is the most important aspect of hot tub water care? In speaking to hot tub customers, service technicians, water care sales teams, retailers, and store owners from all over the world, the answer remains the same: The best way to enjoy the hot tub experience is to maintain the proper sanitizer levels in the water and prevent or remove biofilm buildup in places like plumbing lines, shell surface, or filters. These are the two pillars to hot tub maintenance.