Final answer:
To achieve a concentration of 3.0 ppm of chlorine in a 21,200 kg (or 5,000 gal) pool, 63.6 g of chlorine must be added. Wading pools and spas require careful monitoring and potential adjustment due to a higher bather-to-water volume ratio.
Step-by-step explanation:
Chlorine should be added in a pool to maintain a maximum level of 3.0 ppm for sanitation purposes. To calculate the mass of chlorine needed for a typical 5,000 gal pool, which contains approximately 21,200 kg of water, you would use the following conversion: 1 ppm is equivalent to 1 mg of solute per liter of solution. So for 3 ppm in a 21,200 kg pool, we first convert kilograms to liters (assuming the density of water is 1 kg/L), and then multiply by the desired ppm.
The calculation would look like this: 21,200 kg (assuming 1 kg/L) x 3 mg/L = 63,600 mg, or 63.6 g of chlorine. Therefore, to achieve a concentration of 3.0 ppm of chlorine in a 5,000-gallon pool, you would need to add 63.6 g of chlorine.
In a wading pool or spa, where the volume of water is much less and the concentration of users typically higher, pool managers may often need to adjust the chlorine levels to maintain appropriate sanitization without irritating users' skin and eyes. As spas and wading pools typically have a higher ratio of bathers to water volume, they often require more frequent monitoring and adjustment of chlorine levels to ensure safety and comfort.