How much liquid chlorine should you add to a pool?

It depends on the strength on the label. Per 10,000 gallons of water, to raise free chlorine by 1 ppm:

• 12.5% liquid chlorine: about 10 fluid ounces.
• 10% liquid chlorine: about 13 fluid ounces.
• 6% household bleach (unscented): about 20 fluid ounces.

Scale it from there. A 20,000 gallon pool needs twice as much for the same rise, and climbing 3 ppm takes three times as much as climbing 1.

Measure and multiply. For a rectangle, length times width times average depth, all in feet, times 7.5. For a round pool, diameter times diameter times average depth times 5.9. For an oval, length times width times average depth times 6.7. Those are the same factors Hayward's AquaRite manual uses. Average depth is the shallow end and deep end added together and halved.

Enough to replace what the pool burns off, which you find by testing. Test free chlorine in the evening, add enough to get back to your target, and test again the next evening. After a few days you know your pool's daily loss and can dose it without guessing. In a Florida summer it climbs fast: sun, heat, rain and swimmers all eat chlorine. The CDC minimum is 1 ppm free chlorine, or 2 ppm in a pool with stabilizer. If you would rather not test and dose it yourself, our weekly pool service tests and balances the water every week, and every chemical is included in the monthly price.

Enough to raise free chlorine well above your everyday level, and a lot more for a green pool. Many owners take a clear pool up to around 10 ppm for a routine shock. A pool with algae needs more and needs it held until the water clears, which is covered in how to get algae out of a pool. The step by step is in how to shock a pool.

Yes, if it is plain, unscented bleach with nothing added. It is the same chemical as liquid pool chlorine, just weaker, so it takes about twice as much as 12.5% pool chlorine. Skip anything labeled splashless, scented or with cleaners added.

Yes, and faster in heat. A jug that sat in a hot Florida garage for a couple of months is noticeably weaker than the label says, so buy what you will use in a few weeks and keep it somewhere cool and shaded. The CDC says to store pool chemicals cool and dry and to keep different chemicals from mixing.

In the evening, with the pump running, poured slowly in front of a return. Added at noon, a good part of it is gone to the sun before it does anything.