CPO Pool Calculations and Formulas 2 — Questions and Answers
Question 1: A rectangular pool is 75 feet long, 30 feet wide, and has an average depth of 6 feet. Using 7.5 gallons per cubic foot, what is the pool volume in gallons?
- 13,500 gallons
- 67,500 gallons
- 101,250 gallons (Correct answer)
- 135,000 gallons
Correct answer: 101,250 gallons
Volume = length × width × average depth × 7.5 = 75 × 30 × 6 × 7.5 = 101,250 gallons.
Question 2: A circular pool has a radius of 15 feet and an average depth of 5 feet. Using π ≈ 3.14, what is the volume in gallons?
- 13,247 gallons
- 26,494 gallons (Correct answer)
- 35,325 gallons
- 52,988 gallons
Correct answer: 26,494 gallons
Volume = π × r² × depth × 7.5 = 3.14 × 225 × 5 × 7.5 ≈ 26,494 gallons.
Question 3: A pool contains 120,000 gallons and state code requires the water to turn over every 6 hours. What minimum pump flow rate in GPM is required?
- 200 GPM
- 267 GPM
- 333 GPM (Correct answer)
- 400 GPM
Correct answer: 333 GPM
Divide pool volume by turnover time in minutes: 120,000 ÷ (6 × 60) = 120,000 ÷ 360 = 333 GPM.
Question 4: Which constant is used when calculating the volume of an oval (elliptical) pool?
- 7.5
- 5.9 (Correct answer)
- 3.14
- 0.785
Correct answer: 5.9
Oval pool volume = length × width × average depth × 5.9, where 5.9 accounts for the elliptical shape (≈ π/4 × 7.5).
Question 5: A pool pump operates at 250 GPM. How many gallons does it circulate in 8 hours of continuous operation?
- 30,000 gallons
- 60,000 gallons
- 120,000 gallons (Correct answer)
- 240,000 gallons
Correct answer: 120,000 gallons
250 GPM × 60 min/hr × 8 hr = 120,000 gallons circulated in 8 hours.
Question 6: A pool with an irregular shape has a measured surface area of 800 square feet and an average depth of 4 feet. What is the pool volume in gallons?
- 3,200 gallons
- 12,000 gallons
- 24,000 gallons (Correct answer)
- 32,000 gallons
Correct answer: 24,000 gallons
Volume = surface area × average depth × 7.5 = 800 × 4 × 7.5 = 24,000 gallons.
Question 7: A small spa holds 600 gallons and local code requires it to turn over every 30 minutes. What minimum flow rate in GPM is required?
- 10 GPM
- 20 GPM (Correct answer)
- 30 GPM
- 60 GPM
Correct answer: 20 GPM
GPM = pool volume ÷ turnover time in minutes = 600 ÷ 30 = 20 GPM.
CPO Pool Calculations and Formulas 2
A rectangular pool is 75 feet long, 30 feet wide, and has an average depth of 6 feet.
Using 7.5 gallons per cubic foot, what is the pool volume in gallons?