Flow Rate Calculator
One of the most important ways to maintain a clear, healthy, and inviting community pool is by ensuring adequate water flow through the filtration system. Clogs, restrictions, and mechanical issues may result in insufficient water flow, leading to many different .
Checking the Flow Rate will help to ensure proper circulation and filtration.
Flow Rate Calculator
Enter your pool’s volume (in gallons), using a Turnover Rate of 6, to determine Flow Rate.
FLOW RATE (FR)*
Measures how many gallons of water move through the system per minute.
- May be measured using a flow meter installed in the return line; compare flow meter rate to recommended flow rate (see chart below).
- Must be sufficient to meet the turnover rate required by your local code.
- Daily monitoring is recommended.
- Poor flow rate may be a sign of an obstruction or mechanical problems.
To measure Flow Rate (FR), use this formula:
[Pool Volume gallons] ÷ [Turnover Rate] ÷ 60 [minutes/hour] = FR
Example: What is the flow rate for a 75,000-gallon pool with a turnover rate of 6?
75,000 ÷ 6 ÷ 60 = 208.3 gallons per minute
TURNOVER RATE (TR)*
Measures the time it takes to move the entire volume of the pool through the filtration system back into the pool. One full cycle is one “turnover.”
- New pollutants are always being introduced by bathers and environmental conditions.
- Filtering the water requires continuous circulation.
- Multiple “turnovers” occur every day to ensure adequate filtration.
- Turnover requirements vary depending on the type of pool, expected usage, and regulations.
- The turnover rate determines the necessary minimum flow rate for any pool operation.
- The following turnover rates are sample standards from the Pool and Hot Tub Alliance.
- Pools - 6 hours.
- Spas - 30 minutes.
To measure TR, use this formula:
[Pool Volume gallons] ÷ Flow Rate ÷ 60 [minutes/hour] = [TR]
Example: 200,000-gallon pool with a flow rate of 750 gallons/minute.
200,000 gal. ÷ 750 ÷ 60 = 4.44
*Both flow rate and turnover rate are regulated by local codes.
