Is baking soda the same as the pool-store "alkalinity increaser"?

Yes — alkalinity increaser is sodium bicarbonate, the same compound as baking soda. Buying it as a grocery product is often cheaper for the identical result. Check the label to confirm it is 100% sodium bicarbonate.

Will raising alkalinity also change my pH?

Slightly. Sodium bicarbonate raises pH a little as it raises alkalinity, but far less than soda ash does. Adjust alkalinity first, let it circulate, then fine-tune pH with the pH adjustment calculator.

Why fix alkalinity before pH?

Because alkalinity is what stabilizes pH. If you chase pH while alkalinity is low, it will keep drifting back. Set TA into the 80–120 ppm range first and pH becomes much easier to hold. Retest both with a kit after dosing.

Alkalinity Calculator

Find the baking soda (sodium bicarbonate) needed to raise total alkalinity to your target — from your pool volume and current TA.

Inputs

Pool volume — gallons

gal

Current TA

ppm

Target TA

ppm

Product — baking soda — NaHCO₃

Results update as you type — no submit

Baking soda to add

4.2 lb

≈ 1.91 kg

TA change20 ppm

ProductSodium bicarbonate (baking soda)

Formula

raise TA by 20 ppm in 15,000 gal
baking soda = 4.2 lb ≈ 1.91 kg

Add chemicals to water, never water to chemicals. Broadcast over the deep end with the pump running, then retest before adding more.

Doses are estimates from published product concentrations — always follow the product label, add chemicals to water (never the reverse), test with a kit, and retest after dosing.

MeasureShedmeasureshed.com/calculator/alkalinity-calculator

Alkalinity dose — dose sheetUNITS: US GAL · ppm

Inputs

Pool volume15,000 gal

Current TA70 ppm

Target TA90 ppm

ProductSodium bicarbonate (baking soda)

Results

baking soda to add4.2 lb

Other units1.91 kg

TA change20 TA ppm

Safe dosing: add product to water (never the reverse) · broadcast with the pump running · wait and retest before re-dosing · keep chemicals apart and dry.

Shopping list

☐ 4.2 lb (1.91 kg) — Sodium bicarbonate (baking soda)

Formula

raise TA by 20 ppm in 15,000 gal

baking soda = 4.2 lb (1.91 kg)

Doses are estimates from published product concentrations — always follow the product label, add chemicals to water (never the reverse), test with a kit, and retest after dosing.SHEET 1 OF 1

How it works

Total alkalinity (TA) is the water's buffer — it keeps pH from swinging every time you add a chemical. When TA is low, pH bounces; the fix is sodium bicarbonate, plain baking soda. The calculator finds how much to add from your pool volume and the gap between your current and target TA.

The math comes from chemistry, not a rule of thumb. TA is measured as parts per million of calcium carbonate. Sodium bicarbonate (`NaHCO₃`, `84.0 g/mol`) supplies one unit of alkalinity per molecule, so raising TA by `10 ppm` in `10,000 gal` takes about `1.4 lb` of baking soda. That figure lines up with the service-industry rule of roughly `1.5 lb` per `10,000 gal` per `10 ppm`.

Broadcast baking soda across the pool with the pump running and give it time to circulate before retesting — it dissolves readily but the reading takes a few hours to settle. Baking soda nudges pH up slightly too, so recheck pH after. As always, add product to water and test with a kit before and after dosing.

Worked example

Volume `15,000 gal` · total alkalinity `70 → 90 ppm` (`+20 ppm`)
baking soda = (84.0 ÷ 50.0) × 20 × 15,000 × 3.785 ÷ 1,000 ÷ 1,000
= `1,907 g` = `4.2 lb`

Questions about total alkalinity

About 1.4 lb of sodium bicarbonate per 10,000 gal lifts total alkalinity by 10 ppm. For a 15,000 gal pool going from 70 to 90 ppm, that works out to roughly 4.2 lb. Add it in stages if you are raising TA a lot.

SOURCES — NaHCO₃ 84.0 g/mol · alkalinity as CaCO₃ 50.0 g/eq · Taylor/Orenda ~1.5 lb/10k gal/10 ppm

Doses are estimates from published product concentrations — always follow the product label, add chemicals to water (never the reverse), test with a kit, and retest after dosing.