Free chlorine now and where you want it: how much liquid chlorine, bleach, cal-hypo, trichlor or dichlor to add.
Pool volume (gal)
Free chlorine now (ppm)
Free chlorine you want (ppm)
Common: 3 ppm. With more stabilizer, aim higher.
Your chlorine
Liquid chlorine / bleach
Cal-hypo (shock)
Trichlor (tabs, granules)
Dichlor (granules)
Liquid chlorine / bleach
Cal-hypo (shock)
Trichlor (tabs, granules)
Dichlor (granules)
Strength on the label (%)
Pool chlorine 10 or 12.5 %; household bleach 6 or 8.25 %.
Add
1 qt + 3¼ cups
Exactly
57.6 fl oz (1.7 L)
Estimates. Follow the label on your product. Add one chemical at a time with the pump running, and never mix chlorine and acid — not in the bucket, not in the skimmer.
How it works
Enter your pool volume, the free chlorine your test shows and the level you want. Pick your product and its strength from the label.
Formula: grams of chlorine = ppm to add × gallons × 3.785 ÷ 1000. A 10 % liquid has 10 g of chlorine per 100 ml, so 1 ppm in 10,000 gallons is 378 ml (12.8 fl oz).
Example: 15,000 gallons from 1.0 to 4.0 ppm with 10 % liquid chlorine: 1.70 liters, which is 1 quart + 3¼ cups (57.6 fl oz).
Frequently asked questions
How much bleach do I put in a pool?
With 6 % household bleach, about 21 fl oz per 1 ppm per 10,000 gallons; with 8.25 % bleach about 15.5 fl oz. Use plain, unscented bleach.
Does stabilized chlorine raise CYA?
Yes. Every 1 ppm of chlorine from dichlor adds about 0.9 ppm of CYA, and from trichlor about 0.6 ppm. Liquid chlorine and cal-hypo add none (cal-hypo adds calcium instead).
What free chlorine should I keep?
The CDC Model Aquatic Health Code asks for at least 1 ppm (2 ppm with stabilizer) and no more than 10 ppm to swim. Many home pools keep 2–5 ppm.