Baking soda is the right fix for pool alkalinity.

Yes, that’s exactly what baking soda is for.

Total alkalinity is just a measure of how well your pool water resists pH changes. Baking soda (sodium bicarbonate) raises alkalinity without sending pH through the roof the way soda ash (sodium carbonate) does. That’s why pool stores sell “alkalinity increaser” – it’s literally baking soda in a fancy bag.

The math: about 1.5 pounds per 10,000 gallons raises alkalinity by 10 ppm. Dissolve it in a bucket of pool water first, pour it around the deep end while the pump runs, and test after a few hours. Don’t dump it all in one spot – it can cloud the water temporarily. And yes, the box from the grocery store works exactly the same as the pool-store version for about a quarter of the price.

One thing: baking soda is not pH increaser. If you need to raise pH too, use soda ash (sodium carbonate). If you just need alkalinity, stick with baking soda.

Future You will thank you for not buying the overpriced bag at Leslie’s.