Question: how to raise tdr in hot tub?
Answer: Add 1 tablespoon of baking soda to the hot tub for every 100 gallons of water it holds. For example, add 4 tablespoons of baking soda to a hot tub that holds 400 gallons of water. Turn on the hot tub jets and allow the water to circulate the baking soda for two to four hours. Retest the pH level of the water.