Amazon.com : Hot Tub Things pH and Alkalinity Down - Water Balancing, Crystal Clear Water, Alkalinity Reducer for Spa and Swimming Pool, Maintenance, Comfortable Relaxation, Refreshing, 1.25 Pounds : Home & Kitchen
Hot Tub Things pH and Alkalinity Up (2 lb)
How to Lower pH in a Hot Tub: 12 Steps (with Pictures) - wikiHow