Pool Calculations and Formulas Questions and Answers Flashcards
6 cards from real CPO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Pool Calculations and Formulas Questions and Answers flashcards as text
A rectangular pool is 75 feet long, 42 feet wide, and has an average depth of 5.5 feet. What is the pool volume in gallons?
Answer: 130,178 gallons
Volume equals length times width times depth times 7.48 gallons per cubic foot: 75 times 42 times 5.5 times 7.48 equals approximately 130,178 gallons.
How many pounds of calcium hypochlorite (65 percent available chlorine) are needed to raise the free chlorine by 2.0 ppm in a 50,000-gallon pool?
Answer: 1.28 pounds
Using standard dosing references, approximately 1.28 pounds of 65 percent cal-hypo is needed for this adjustment.
A circular spa has a diameter of 8 feet and a uniform depth of 3.5 feet. What is its volume in gallons?
Answer: 1,316 gallons
Circular volume equals pi times radius squared times depth times 7.48: 3.14 times 16 times 3.5 times 7.48 equals approximately 1,316 gallons.
What flow rate in GPM is required for a 120,000-gallon pool to achieve a 6-hour turnover?
Answer: 333 GPM
Flow rate equals pool volume divided by turnover time in minutes: 120,000 divided by 360 equals 333 GPM.
The Langelier Saturation Index of a pool reads negative 0.5. What does this indicate?
Answer: The water is corrosive
A negative LSI value indicates corrosive water that will dissolve calcium from plaster, grout, and metal surfaces. The ideal LSI range is negative 0.3 to positive 0.3.
A pool operator needs to lower pH from 7.8 to 7.4 in a 60,000-gallon pool. Approximately how much muriatic acid (31.45 percent HCl) is needed?
Answer: 1 gallon
Approximately 1 gallon of 31.45 percent muriatic acid is needed to lower the pH by 0.4 units in a 60,000-gallon pool, though actual amounts vary with alkalinity.