Is baking soda the right fix for pool alkalinity?

Yes, baking soda raises alkalinity without spiking pH like soda ash does. Use about 1.5 pounds per 10,000 gallons to raise alkalinity by 10 ppm. Dissolve it in a bucket of pool water, pour it around the deep end with the pump running, and test after a few hours. Grocery store baking soda works the same as pool-store “alkalinity increaser” for a quarter of the price.