In a 1,000 gallon pool, 1.3 fl oz (38 mL) of 10% liquid chlorine raises free chlorine by 1 ppm. The usual evening top-up from 2 to 6 ppm (CYA 40) takes 5.1 fl oz (151 mL). With 12.5% chlorine use 1 fl oz per ppm; with 8.25% bleach, 1.5 fl oz.
| Free chlorine | 10% | 12.5% | 8.25% bleach | 6% bleach |
|---|---|---|---|---|
| Raise 1 ppm | 1.3 fl oz | 1 fl oz | 1.5 fl oz | 2.1 fl oz |
| Raise 2 ppm | 2.6 fl oz | 2 fl oz | 2.9 fl oz | 4.1 fl oz |
| Raise 3 ppm | 3.8 fl oz | 3.1 fl oz | 4.4 fl oz | 6.2 fl oz |
| Raise 4 ppm | 5.1 fl oz | 4.1 fl oz | 5.8 fl oz | 8.3 fl oz |
| Raise 5 ppm | 6.4 fl oz | 5.1 fl oz | 7.3 fl oz | 10 fl oz |
| Shock 2 → 16 ppm | 18 fl oz | 14 fl oz | 20 fl oz | 29 fl oz |
In kitchen measures: 1 ppm is about 2½ tbsp of 10% chlorine, and 2 to 6 ppm about ⅝ cup.
Add
5.1fl oz
of Liquid chlorine 10%
151 mL⅝ cup
Raises free chlorine from 2 ppm to 6 ppm in 1,000 gal. Best added at dusk.
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
Save this test and get reminded when it is time to retest.
Pool Calc for iPhoneComing soon to the App StoreLiquid 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 18 fl oz (530 mL) 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.
A 1,000 gallon pool is usually a large inflatable, a stock tank or a small frame pool. Doses this small are easy to overshoot: one extra splash is several ppm. Measure liquid chlorine with kitchen measures you keep only for pool chemicals, and test after every addition.
Small pools also lose chlorine fast on sunny days because there is so little water. Test daily, and when the numbers drift far off it is often quicker to drain and refill than to correct them.
About 1.3 fl oz of 10% liquid chlorine per 1 ppm of free chlorine. To go from 2 to 6 ppm, add 5.1 fl oz.
At CYA 40 the shock level is 16 ppm. From 2 ppm that is 18 fl oz of 10% liquid chlorine. Higher CYA needs more: the shock level is 40% of CYA.
Yes, if it is plain unscented bleach. It is weaker, so use more: 1.5 fl oz of 8.25% bleach per ppm in 1,000 gallons.