Calculating Pool Turnover Rate

All of these factors depend on:

1. Pool Volume –_total amount of water in the pool (in gallons or liters).
2. Flow Rate – How much the pool pump circulates water per minute (gpm and/or lpm).

Step 1: Calculate the Pool Turnover Time

The turnover time: this is calculated by dividing the total pool volume by the pump’s flow rate.

Formula (in Hours):

$\text{Turnover Time (hours)} = \frac{\text{Pool Volume (gallons)}}{\text{Flow Rate (gallons per minute)} \times 60}$

Step 2: Required Turnovers per Day

For good filtration, most pools need to circulate their entire volume of water to the filter at least every 6-8 hours. The recommended turnover frequency per day is:

Formula:

$\text{Turnovers per Day} = \frac{24}{\text{Turnover Time (hours)}}$

Step 3: Then, determine if your turnover rate is pool standard.

• Residential pools: 1 turnover / 8 hours (3 times per day)
• Commercial swimming pools: 1 turnover every 6 hours (4 times each day)
• Hot tubs/spas: 1 turnover every 30 minutes to 1 hour

If the turnover time is greater than the recommended, then you would need to either increase your flow rate through the pump or increase the amount of time the pump runs.

Example Calculation

Given Data:

• Pool Volume: 20,000 gallons
• Flow Rate: 50 gallons per minute

Step 1: Calculate Turnover Time

$\text{Turnover Time} = \frac{20,000}{50 \times 60} = 6.67 \text{ hours}$

Step 2: Calculate Turnovers per Day

$\text{Turnovers per Day} = \frac{24}{6.67} \approx 3.6$

Final Output for the Example:

• Turnover Time: 6.67 hours
• Number of turnovers/day: 3.6 (In line with residential pool standards)