Shock the pool

Into 21,100 gal of water, add

6.40qt 6.06L

HASA CHLOR — sodium hypochlorite, 12.5%. Free chlorine from 0.5 ppm to 10.0 ppm.

Shocking works to the top of the range the code allows, 10 mg/L of free chlorine under Florida 64E-9.004(1)(d)2. That is a limit, not a level anyone publishes as a target. The band the rest of this site works to is 2 to 4 ppm, and the pool is back inside it before it is used again.

Your pool

Length

feet, the long side

Width

feet

Shallow end

inches of water, not wall height

Deep end

inches of water

Your reading

what your kit reads

Target

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

Each product makes the whole change of +9.5 ppm on its own, so add one of them, not all.
Product	Add	Also moves
HASA CHLOR sodium hypochlorite 12.5%	6.40 qt 6.06 L	nothing else measured
Multi-Chlor sodium hypochlorite 12.5%	6.40 qt 6.06 L	nothing else measured
Cal Hypo 68% Granular Pool Shock calcium hypochlorite 68.0%	2.46 lb 1.11 kg	nothing else measured

The HASA CHLOR label says: “10 fluid ounces per 10,000 gallons”.

In steps, if you would rather

Split into 5 equal steps of 1.28 qt each: add one, run the pump, and test again before the next.

To reach	Total added
2.4 ppm	1.28 qt
4.3 ppm	2.56 qt
6.2 ppm	3.84 qt
8.1 ppm	5.12 qt
10.0 ppm	6.40 qt

Where the band comes from

Source	Range
Florida 64E-9.004 (1)(d)2 conventional pool	1.0–10.0 ppm
Florida 64E-9.004 (1)(d)2 spa or hot tub	2.0–5.0 ppm
Florida 64E-9.004 (1)(d)2 indoor pool	up to 5.0 ppm
CDC Healthy Swimming stabilised pool	2.0 and up 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.

Florida 64E-9.004 (1)(d)2 · http://flrules.elaws.us/fac/64e-9.004 · 2026-09-17
HASA · https://hasa.com/pool-chemical-calculator · 2026-09-17
CDC Healthy Swimming · https://www.cdc.gov/healthy-swimming/about/home-pool-and-hot-tub-water-treatment-and-testing.html · 2026-09-17
HASA CHLOR · https://hasa.com/product/hasachlor · 2026-09-17
Multi-Chlor · https://hasa.com/products/ · 2026-09-17
Cal Hypo 68% Granular Pool Shock · https://pyrockchemical.com/products/pool-shock-calcium-hypochlorite-65-for-sale · 2026-10-01

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.