How the pool alkalinity calculator works
Baking soda, sold as sodium bicarbonate, raises alkalinity with very little effect on pH. Around 1.5 pounds per 10,000 gallons moves TA up by 10 ppm.
Lowering TA takes acid poured in one spot with the pump off, then aeration to bring pH back up. The calculator gives the acid volume for the drop you asked for.
The formula, step by step
Baking Soda (lbs) = (Target TA - Current TA) / 10 x 1.5 x (Gallons / 10,000)
- Subtract your current TA from your target TA.
- Divide by 10 to count how many 10 ppm steps you need.
- Multiply by 1.5 pounds for each step.
- Scale by your pool size in units of 10,000 gallons.
Worked example
A 24,000 gallon pool reads 60 ppm TA and you want 100 ppm.
Gap = 40 ppm, which is four steps of 10 ppm.
4 x 1.5 x 2.4 = 14.4 pounds of baking soda, best added across two days.
Watch it done
This short video walks through the same job in real life, so you can match what you see on screen to what you do at the pool.
Tips before you start
Keep TA between 80 and 120 ppm for plaster pools and 100 to 140 ppm for vinyl and fiberglass. Below 80 your pH bounces every time it rains.
Add no more than half the dose at once. Broadcast it over the deep end with the pump running, then retest six hours later.
Pool Alkalinity Calculator FAQs
How much baking soda raises alkalinity?
About 1.5 pounds per 10,000 gallons for each 10 ppm you need. A 20,000 gallon pool needs 3 pounds for that same 10 ppm bump.
Will baking soda change my pH?
Slightly. It nudges pH upward, so test both after the water has circulated for a few hours.
How do I lower total alkalinity?
Add muriatic acid, then aerate with jets or a fountain. Aeration raises pH back up while alkalinity stays down.