How many 3-inch chlorine tabs should I use?
How many 3-inch chlorine tabs should I use? To use the right number of tablets, always round your pool volume up to the nearest unit of 5,000 gallons. For instance, your pool has a capacity of 20,000 gallons, you would add four chlorine tablets. But if your pool holds just 16,000 gallons, you’d still use four, three-inch chlorine tablets.