We are not aware of a specific standard for pools. However, ACI 350.1-10, “Specification for Tightness Testing of Environmental Engineering Concrete Containment Structures,” specifies a volume loss of 0.05% of volume per day conducted over a 72-hour test period for “hydrostatic tightness testing of open liquid containment structures. Specifics of conducting the test can be found in the ACI 350.1-10 document.
It should be noted that the pool should be filled and allowed to saturate for 3 days before beginning the measurements.