A pool with 10,000 gallons of water requires one or two 3-inch chlorine tablets per week to maintain the recommended 1 to 3 parts per million. Test pool water regularly, and adjust the amount of chlorine as needed.
In order to raise the chlorine level by 1 part per million, multiply the pool's total gallons of water by 0.00013, and add that many ounces of chlorine. Each 3-inch chlorine tablet has about 7 ounces of chlorine in it.
Chlorine tablets are intended to be placed in automatic chlorine feeders, floaters or skimmers. The tablets dissolve slowly and release chlorine continuously into the pool.