DescriptionAlkalinity Up for hot tubs increases Total Alkalinity (TA) and will help bring up low pH to the proper range. Helps reduce corrosion of spa metal parts and damage to pump motors and heaters. Alkalinity Up buffers the water to minimize pH bounce, and optimizes the effectiveness of bromine and other sanitizers. Fast dissolving and optimized for solubility in spa water, Alkalinity Up is an alkalinity increaser which raises TA, without raising pH to excessively high levels. Fast-dissolving form for spas Raises TA Buffers pH Product notes: Check spa water with test strips to achieve balance. Adjust Total Alkalinity (TA) first, then adjust for proper pH range. Proper TA will buffer pH, preventing pH fluctuations. Contains 100% granular sodium bicarbonate (also referred to as sodium hydrogen carbonate). pH 8.3. Sometimes called Spa Up.