Pool Alkalinity Levels Chart

Quick Answer

Ideal total alkalinity (TA) for most pools is 80–120 ppm. TA acts as a pH buffer — low TA causes rapid pH swings, while high TA causes pH to drift upward and resist downward correction. Always adjust TA before making pH adjustments.

Reference table

TA levelStatusEffectAction
< 60 ppmToo lowpH swings; corrosion riskAdd sodium bicarbonate (baking soda)
60–80 ppmLowSome pH instabilityAdd bicarb; retest after 24 h
80–120 ppmIdealpH stable and bufferedNone — maintain range
120–150 ppmElevatedpH drifts upwardAdd muriatic acid in small doses
150–200 ppmHighpH very resistant to correction; scale riskLower with acid; aerate to restore pH
> 200 ppmVery highSevere pH drift; cloudy water; scalePartial drain + refill + rebalance

Frequently Asked Questions

What is total alkalinity in a pool?

Total alkalinity measures the concentration of alkaline substances (mainly bicarbonates and carbonates) dissolved in pool water. These substances neutralize acid, preventing wild pH swings. It is measured in ppm (parts per million) with a test kit.

How do I raise pool alkalinity?

Add sodium bicarbonate (baking soda). Use 1.5 lb per 10,000 gallons to raise TA by approximately 10 ppm. Broadcast it across the pool with the pump running, and retest after 24 hours.

How do I lower pool alkalinity?

Add muriatic acid (pH reducer) directly in front of a return jet with the pump running. After adding, run jets or aerate with the cover off to allow CO2 to escape and let pH recover naturally. Repeat as needed over several days.

Does alkalinity affect chlorine?

Yes indirectly. High alkalinity keeps pH elevated, which reduces chlorine effectiveness. Low alkalinity allows pH to drop, which is corrosive and also affects sanitizer balance. Correct TA first, then pH, then chlorine for best results.

Calculate your dose

Pool Chemical Calculator

Alkalinity Calculator

Also see: Pool Chemical Levels Chart · pH Levels Chart

Last updated: June 2026