When you operate a pool or spa, the safety of your swimmers and the clarity of your water become top priorities. Your swimmers require a safe environment and good water clarity. For you to provide sanitary and clear water you must keep the swimming pool free of harmful microorganisms. Circulation plays a key role in this process. The pool’s pump must move the proper amount of water through its filtration system and return the filtered water to the pool. As a result anyone involved with the operation of a pool or spa should familiarize themselves with the concept of a turnover rate. Understanding the turnover rate allows you to determine if your pump circulates the proper amount of water for safe swimming.
The turnover rate is the amount of time it takes a pool’s circulation system to move all the water in the pool through the filtration equipment. For public pools local health departments set required turnover rates. Since I provide Pittsburgh pool services, I focus on the standards that apply to my area. Allegheny County, Pennsylvania sets the following standards for turnover rates.
Wading Pools and Spray Pools: 2 hours or less
Hot Tubs and Spas: 30 minutes of less
Pools built before January 1, 2008: 8 hours or less
Pools built after January 1, 2008, 6 hours or less
If you operate a pool at a public facility, the regulations dictating proper circulation make it critical that you can calculate a pool’s turnover rate.
Figuring a turnover rate requires knowing the volume of water in the pool and a reliable flow meter. All facilities should have a flow meter installed downstream of all equipment just before the water is returned to the pool. The flow meter will give a flow rate reading in gallons per minute. Once you note this reading, you can determine your pool ‘s turnover rate. The formula for determining the turnover rate is:
- Turnover Rate (hr) = Pool Volume / Flow Rate / 60 min/hr
For example, if you have have a 150,000 gallon pool with a flow rate of 425 gpm your turnover rate is 5.88 hours.
If you apply the formula above, and find your turnover rate falls outside of code, the problem should be corrected immediately. I suggest starting this process by looking for obstructions restricting flow. For example there may be debris in your skimmers and lint catchers, or your filter may need backwashed. Cleaning skimmer baskets, clearing lint catchers, and filter backwashing are all maintenance tasks that need performed on a routine basis. Allegheny Pool Services Co. performs these tasks for our clients with maintenance contracts to help keep their swimmers happy and their operation running smoothly.
I hope you found this explanation of the turnover rate. helpful. We are here to assist you with providing your patrons the best swimming experience possible. If you have any questions regarding the topics in this article or would like to discuss any other pool issues please contact us. You can also find more information at our homepage.
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