It is essential to know the size and volume of the pool or spa you are operating. The following steps and formulas will assist in determining the size and volume of the pool. First determine the Surface Area, then Average Depth, and finally Volume of Pool.

VOLUME OF POOL

Volume equals the surface area multiplied by the average depth of the pool or spa multiplied by 7.5 which is the conversion from cubic feet to gallons.

Volume = (S.A.) x (Ave. Depth) x (7.5)

EXAMPLE

A pool that is 15 feet by 30 feet with a depth of 5 feet in the deep end and 3 feet in the shallow end would have a surface area of 450 square feet and an average depth of 4 feet and a volume of 13,500 gallons.

Surface Area = 15 ft. x 30 ft = 450 sq. ft.

Average depth = (5 ft. + 3 ft.) / 2 = 4 ft.                                

TURNOVER RATE -Turnover rate is the time required to recirculate the entire volume of water in the pool or spa through the filter.

FLOW RATE - Flow rate is the amount of water going through the recirculation system, usually measured in gallons per minute.

Flow rate = Volume of the pool / Turnover rate