Enter your pool volume, current total alkalinity (TA), and target TA to get an exact baking soda dose. Target TA is 80–120 ppm for most pools.
Total alkalinity (TA) measures how much bicarbonate, carbonate, and hydroxide is dissolved in your water. It acts as a chemical buffer — it absorbs pH changes before they affect the bulk water. Without enough TA, small additions of acid or base swing pH wildly. Too much TA pushes pH upward and makes it difficult to lower, no matter how much acid you add.
The target range is 80–120 ppm. At the lower end (80–100 ppm), pH is well-buffered and acid additions are predictable. At the higher end (above 120 ppm), pH tends to drift upward toward 8.0 and above — wasting chlorine and requiring more acid to correct.
Broadcast baking soda around the pool perimeter, or pre-dissolve it in a bucket of pool water before adding. Avoid dumping it directly in front of the skimmer. For large doses (more than 3 lbs), split into multiple additions spaced 4–6 hours apart and retest between doses.
Baking soda is sodium bicarbonate (NaHCO₃, molecular weight 84). Total alkalinity is measured as mg/L of CaCO₃ equivalent (molecular weight 50). To raise TA by 1 ppm in 1 liter of water, you need enough bicarbonate to provide 1 mg of CaCO₃-equivalent alkalinity — which works out to 84/50 = 1.68 mg of NaHCO₃ per mg of CaCO₃ alkalinity.
At 10 ppm per 10,000 gallons, this works out to about 22 oz (1.4 lbs) of baking soda — consistent with the standard rule of thumb you'll find on product labels.
A 15,000-gallon pool tests at TA 65 ppm. Target is 100 ppm — a rise of 35 ppm.
35 × 15,000 × 3.785 × 1.68 ÷ (1,000 × 28.35) = 117 oz ≈ 7.3 lbs. Add 2–3 lbs at a time, wait 4–6 hours, retest before adding more.
For a 10,000-gallon pool: about 1.4 lbs (22 oz). For a 15,000-gallon pool: about 2.1 lbs (33 oz). The dose scales directly with pool volume and TA rise — use the calculator above for your exact numbers.
80–120 ppm. In practice, 80–100 ppm is the sweet spot — enough buffer to stabilize pH without causing upward pH drift. If TA creeps above 120 ppm, pH becomes difficult to keep in range and you'll find yourself adding muriatic acid more frequently.
Baking soda (sodium bicarbonate) raises TA with minimal effect on pH — the right choice when TA is low but pH is already in range. Soda ash (sodium carbonate, sold as "pH increaser") raises pH significantly and also raises TA. If both pH and TA are low, soda ash can address both; if only TA is low, use baking soda. See the baking soda vs. soda ash guide for a full comparison.
Yes. Adding a large dose at once can temporarily cloud the water and cause pH to rise above its target range. Add no more than 2–3 lbs per 10,000 gallons in a single dose. Wait 4–6 hours, let the pump circulate the water fully, retest, and add more if needed.
TA drops mainly from adding muriatic acid to control pH — that's the expected tradeoff. If you're dosing acid often, TA will drift down over a season. Raise it back with baking soda when it falls below 80 ppm. Rain dilution (from acidic rain) and CO₂ outgassing in aerated pools or spas also contribute to TA loss over time.
PoolChem Tracker calculates your baking soda dose automatically from your current readings — no calculator required. It also tracks your history so you can see how TA trends over time.
