Staff Answer
Jul 31, 2026 - 12:50 PM
Some variance between different flow measurements is always possible because the SmartFlo AF calculates flow from pump operating data rather than measuring it with a mechanical flow sensor. There are also two different comparisons that may be involved: the pump’s displayed GPM versus an external flow meter, or its displayed GPM versus the programmed target.
If comparing the pump’s displayed GPM with a physical flow meter, the two readings may not match exactly. Some variance should always be allowed since the flow is being measured by two different methods. For the most meaningful comparison, allow the pump to complete its priming cycle and operate at a stable flow. Comparisons made at very low operating speeds may show a larger percentage difference.
The displayed flow may also temporarily differ from the programmed target if hydraulic conditions have changed since the pump last calibrated. The pump recalibrates during its startup priming cycle, so the conditions present at that time are important. Confirm that:
The pump becomes completely primed and remains full of water.
The pool water level is adequate and air is not being drawn through the skimmer or suction plumbing.
The pump and skimmer baskets are clean.
The filter is not excessively restricted.
The valves are in their normal operating positions.
The priming speed has not been reduced substantially from its default setting. If it has, consider incrementally raising it and observing the results after another complete startup and priming cycle.
Under normal circumstances, the calculated flow should remain within a relatively small range of variance. A consistent difference between a 45 GPM target and a 36 GPM display is wide enough that we would recommend troubleshooting it.
If the issue is about the displayed and target flow rates, and if for some reason this does not align more closely after the pump continues to calibrate and the factors above have been checked, please contact CircuPool Support so we can help troubleshoot and review the pump settings and the condition of the pool system. Before contacting us, record the programmed target GPM, displayed GPM, RPM, and wattage while the program is running, and have access to the pump’s app. This information will help us identify whether the difference is related to calibration, hydraulic conditions, or pump settings.
Add New Comment