After your pool has been winterized, monitor the water level to make sure it is not leaking. When water temperatures drop, existing cracks can open due to terminal contraction causing a leak that may not in the summer.
Vynyl liner pools may have the same type of leak around the step gaskets. If you see that your pool is leaking make sure you keep the water level up so it does not damage the liner and call NPS Leak Detection. 336-971-5809