Summarize:

This will raise the alkalinity of the water by 10 ppm. Adjust the values to determine how much baking soda you need to add for the volume of your pool. For example, if you want to go from 60 ppm to 80 ppm in a 10,000 US gal (38,000 L) pool, you would add 2.5 pounds (1,100 g) of baking soda. Adding too much baking soda to the water at a time could raise the pH of the water. Let the baking soda settle and mix with the water before adding more. If you need to raise the alkalinity further, wait until the next day to add more baking soda. Use a circular motion as you pour the baking soda. It may cause some cloudiness in the water initially. The baking soda will sink to the bottom of the pool and settle before it begins mixing. To avoid cloudiness in the water, pour the baking soda directly into the skimmer. Your pool water needs to pump and circulate through a full cycle before you retest the water. Check the alkalinity using your test kit.  Let the pool run for a full pump cycle, which takes about 10 hours, before swimming. If your alkalinity levels are still off after the first baking soda treatment, add more baking soda to reach the desired ppm.
Add 1.25 lb (570 g) of baking soda per 10,000 US gal (38,000 L) of water. Use only 2 pounds (910 g) of baking soda per day. Pour the baking soda into the deep end of the pool. Retest the water after 10 hours and make further adjustments if necessary.