poolchemistrycalc

Raise total alkalinity

Into 21,100 gal of water, add

11.80lb 5.35kg

HASA Alkalinity Up — sodium bicarbonate, 100.0%. Total alkalinity from 60 ppm to 100 ppm.

Total alkalinity on one scale: the band 60–180, the ideal band 80–120, the reading now at 60 ppm, and an arrow to 100 ppm carrying 11.80 lb. reads now 60 ppm target 100 ppm ideal code 60 80 120 180 11.80 lb +40 ppm with HASA Alkalinity Up

Your pool

feet, the long side
feet
inches of water, not wall height
inches of water
what your kit reads
where you want it

The quantity, the drawing, every product row and every step on this page are worked again as you type.

At 21,100 gal

Every product that does this

This product makes the whole change of +40 ppm on its own.
Product Add Also moves
HASA Alkalinity Up
sodium bicarbonate 100.0% 		11.80 lb
5.35 kg		 nothing else measured

The HASA Alkalinity Up label says: “1.5 lbs per 10,000 gallons for approximately a 10 ppm alkalinity increase”.

In steps, if you would rather

Split into 5 equal steps of 2.36 lb each: add one, run the pump, and test again before the next.

To reach Total added
68 ppm 2.36 lb
76 ppm 4.72 lb
84 ppm 7.08 lb
92 ppm 9.44 lb
100 ppm 11.80 lb

Where the band comes from

Source Range
COMAR 10.17.01.45 A(2)
conventional pool 		60–180 ppm
COMAR 10.17.01.45 A(2)
spa or hot tub 		60–180 ppm

Pool and spa rules are adopted and amended state by state, and most of the ranges here are written for public pools. Confirm every figure against the code your jurisdiction has adopted and against your own product label.

Other adjustments

Updated October 2026

Sources and dates

Ranges are quoted from the code named beside them, product strengths from the manufacturer's own product page, each retrieved on the date shown.

This site publishes calculated water volumes and chemical quantities for home pool and spa owners. It is not a health, safety or professional service, and it does not replace the instructions printed on the product you are holding. Not affiliated with, endorsed by or sponsored by HASA, Pyrock Chemical, Pentair, Hayward, Sonoma Hot Tubs, the Centers for Disease Control and Prevention, or any state health department. Product names are the trademarks of their owners and appear here only to identify the strength of what is in the container.