A 15 x 30-foot oval pool with an average depth of 48 inches holds 12,000 gallons of water. A pool with the same exterior dimensions and an average depth of 52 inches holds 14,800 gallons of water.
It is necessary to know a pool's capacity in order to calculate the amount of chemicals to add to the water. When using liquid chlorine, 11 ounces should be added each day for every 10,000 gallons of water. To shock a pool that is out of balance, up to 104 ounces of liquid chlorine is needed for every 10,000 gallons. That same amount is needed to clean a pool after winter.