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The pH scale ranges from 0 (extremely acidic) to 14 (extremely alkaline). Baking soda typically registers at a pH of about 8.4, slightly above neutral (7). Because of this, you cannot raise the pH of a water body beyond 8.4 with baking soda alone; however, you can shift a solution that is below 8.4 toward neutral or mild alkalinity.
Insert the test strip into the water and wait 10-30 seconds, or follow your meter's instructions. Compare the resulting color or reading to the reference chart to determine the current pH.
If the pool's pH is under 7.2, add approximately 3 lb (1.4 kg) of baking soda per 10,000 gal (37.9 m3). For a pH between 7.2 and 7.5, add about 2 lb (0.9 kg) per 10,000 gal. If the pH is already above 7.5, no addition is required.
For hot tubs, add 1/3 cup of baking soda per 500 gal (1,900 L) for each 0.1-point increase needed. For example, a 1,000-gal tub at pH 7.0 would need roughly 1 1/3 cups.
To make a gallon of drinking water mildly alkaline, add 1/4 tsp (1.3 g) of baking soda. Note that while some anecdotal reports link this practice to weight loss, scientific evidence is limited, and you should consult a healthcare professional before making dietary changes.
After any adjustment, retest the water after 24-48 hours and repeat as necessary to reach the desired pH range.
