Alkalinity calculator
Add about 6.8 lbs of baking soda (sodium bicarbonate) to raise TA by 30 ppm. Add in thirds, circulating and retesting between.
Treat this as a starting dose: add less than the full amount when unsure, circulate for a few hours, retest, repeat. Always follow your product's label.
Total alkalinity is the buffer that keeps pH stable, so getting it into the 80–120 ppm range is worth doing precisely — the calculator above tells you how much baking soda to add to raise it, or how much acid to lower it, without guessing.
Raising vs lowering
Enter your volume, current TA, and target, and the tool sizes the dose for the direction you need. To raise alkalinity, it calculates sodium bicarbonate (baking soda) — a gentle chemical that lifts TA well and pH only slightly. To lower it, it calculates acid, which drops both TA and pH. Knowing which way you're going, and by how much, is what turns a vague "add some baking soda" into an accurate adjustment.
Why precise TA pays off
Alkalinity is the foundation of stable chemistry, so dialing it in makes everything downstream easier. When TA sits in range, pH holds steady and stops drifting or bouncing; when TA is off, you fight pH endlessly. That's why it's worth using the calculator to get TA right first rather than approximating — a precise alkalinity adjustment saves you repeated pH corrections later.
Dose, circulate, retest
Add the calculated amount with the pump running and let it circulate for several hours before retesting, since alkalinity takes time to distribute. If you have a lot of ground to cover, add in stages and retest between rounds rather than one huge dose. After TA is in range, recheck pH and nudge it into the 7.2–7.6 band — do alkalinity first, pH second, and neither will fight you.
Frequently asked questions
What does total alkalinity mean in a pool?
Total alkalinity is the water's buffering capacity. In plain English, it affects how easily pH moves up or down.
How do I raise pool alkalinity?
Pool owners commonly use sodium bicarbonate or alkalinity increaser. The calculator should estimate dose based on gallons, current alkalinity, target alkalinity, and product label strength.
How do I lower pool alkalinity?
Lowering alkalinity usually involves acid additions and aeration to bring pH back up. Do it slowly, test often, and follow product labels.
Can alkalinity cause cloudy pool water?
High alkalinity can contribute to pH drift, scaling, and cloudy water. It is not the only cause, so test chlorine, pH, calcium hardness, and filter performance too.
Should I adjust alkalinity before pH?
If alkalinity is far off, correct it before chasing pH. If pH is dangerously low or high, bring pH into a safer range first, then work on alkalinity in smaller steps.
Embed this calculator (free)
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