Calculators

Alkalinity Adjustment

Adjustment inputs

Total alkalinity is treated as ppm as CaCO3.

Pool volume gal Product Current total alkalinity ppm Target total alkalinity ppm Label active ingredient % Display unit

Product note

Select the active ingredient from the product label.

Prefilled calculator link

Verify before applying a dose

Verify the reading, pool volume, and product concentration against the label. Follow label and site directions; for large corrections, dose in stages, circulate, and retest before adding more.

Dry product addition -

Enter readings to calculate an adjustment.

Read the Alkalinity Adjustment guide.

Target after mixing -

TA increase -

Product basis -

Field factor -

How PoolKit calculates the dose

PoolKit converts the target alkalinity increase to grams of CaCO3-equivalent alkalinity, then divides by the selected product's equivalent fraction and the label active ingredient percentage. The result is dry product weight for full mixing in the entered pool volume.

The pH impact worksheet estimates the pH after this alkalinity dose when current pH, temperature, and CYA readings are available. Sodium carbonate is included because it is a common field product, but it should be selected only when the label and the intended pH movement match the job.

Sources: PubChem sodium bicarbonate, PubChem sodium carbonate, PubChem cyanuric acid, ppm as CaCO3 equivalent stoichiometry, and carbonate/cyanurate acid-base equilibrium.

Product selection

Use sodium bicarbonate when the field product is alkalinity increaser or the label lists sodium bicarbonate, sodium hydrogen carbonate, NaHCO3, or CAS No. 144-55-8.

Use sodium carbonate only for soda ash or pH Up products whose label matches sodium carbonate, Na2CO3, or anhydrous sodium carbonate.

When sodium carbonate is selected because pH needs to move up, check the worksheet below or open the pH Up calculator with these product details.

Field use

PoolKit shows the full calculated dose. Large corrections should be staged, circulated, and retested because pool volume, product labeling, and test readings all carry field error.

Label directions, site procedures, and local requirements take priority over calculator output.

pH impact worksheet

Estimated from the alkalinity dose above, carbonate balance, CYA, and water temperature.

Open pH Up

Current pH Water temperature Cyanuric acid ppm

Estimated pH after dose -

Enter pH readings to estimate impact.

pH change -

Estimated TA -

Product dose -

Product basis -

Step	Formula	Value Used
Pool volume	`gallons x 3.785411784`	-
Alkalinity increase	`target TA - current TA`	-
Product chemistry	`formula, molar mass, alkalinity equivalents`	-
Product equivalent fraction	`(equivalents x 50.04345) / molar mass`	-
Label active ingredient	`active ingredient percent / 100`	-
Effective product fraction	`equivalent fraction x active fraction`	-
Required CaCO3 equivalent	`liters x ppm increase / 1000`	-
Product dose	`required CaCO3 equivalent / effective fraction`	-
Expected total alkalinity	`current TA + increase`	-

The dose is based on total alkalinity as CaCO3 equivalent, not adjusted carbonate alkalinity.

If the field product includes other active ingredients or a different hydrate form, do not use it here until the calculation basis is known.