How much liquid chlorine for a 15,000 gallon pool

In a 15,000 gallon pool, 19 fl oz (568 mL) of 10% liquid chlorine raises free chlorine by 1 ppm. The usual evening top-up from 2 to 6 ppm (CYA 40) takes 0.6 gal (2.3 L). With 12.5% chlorine use 15 fl oz per ppm; with 8.25% bleach, 22 fl oz.

Liquid chlorine doses for 15,000 gallons

15,000 US gallons (56,781 L). The last row is a shock (SLAM) at CYA 40.
Free chlorine10%12.5%8.25% bleach6% bleach
Raise 1 ppm19 fl oz15 fl oz22 fl oz31 fl oz
Raise 2 ppm0.3 gal31 fl oz0.34 gal0.48 gal
Raise 3 ppm0.45 gal0.36 gal0.51 gal0.73 gal
Raise 4 ppm0.6 gal0.48 gal0.68 gal0.97 gal
Raise 5 ppm0.75 gal0.6 gal0.85 gal1.2 gal
Shock 2 → 16 ppm2.1 gal1.7 gal2.4 gal3.4 gal

Run it with your numbers

gal

Not sure? Work out your pool volume.

%
ppm

Never added stabilizer? Enter 0.

ppm
ppm

Set from your CYA until you change it.

Add

0.6gal

of Liquid chlorine 10%

77 fl oz2.3 L

Raises free chlorine from 2 ppm to 6 ppm in 15,000 gal. Best added at dusk.

  • Side effects: Salt +6.6 ppm.
  • Pour it slowly in front of a return jet with the pump running.

Check the product label. Strengths vary by brand, so enter the % printed on yours. Add one chemical at a time, into the water, and never mix chemicals.

With CYA at 40 ppm: minimum free chlorine 3 ppm, target 6 ppm, shock level 16 ppm. FC/CYA chart

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About liquid chlorine

Liquid chlorine adds almost nothing but chlorine. As it is used up it leaves a little salt behind (about 1.6 ppm per ppm of chlorine), which is harmless. It loses strength in storage, faster in a hot garage, so buy it fresh and keep it shaded.

Your target depends on your stabilizer (CYA). At CYA 40 the minimum is 3 ppm and the daily target about 6 ppm. At CYA 60 those become 4.5 and 7.5 ppm. Shocking at CYA 40 means holding 16 ppm, which takes 2.1 gal (7.9 L) from 2 ppm in this pool.

Never pour chlorine and acid together or in the same spot. Add one, run the pump for 30 minutes, then add the other.

Dosing a 15,000 gallon pool

That is about the size of a 14 × 28 ft in-ground pool averaging 5 ft deep (about 14,660 gal). 15,000 gallons is a typical backyard pool. Measure the volume once rather than trusting the builder’s brochure: an error of 20% in gallons makes every dose 20% off. The pool volume calculator takes a minute.

Questions

How much liquid chlorine do I put in a 15,000 gallon pool?

About 19 fl oz of 10% liquid chlorine per 1 ppm of free chlorine. To go from 2 to 6 ppm, add 0.6 gal.

How much liquid chlorine to shock a 15,000 gallon pool?

At CYA 40 the shock level is 16 ppm. From 2 ppm that is 2.1 gal of 10% liquid chlorine. Higher CYA needs more: the shock level is 40% of CYA.

Can I use bleach instead of liquid chlorine?

Yes, if it is plain unscented bleach. It is weaker, so use more: 22 fl oz of 8.25% bleach per ppm in 15,000 gallons.