When Winterizing a Swimming Pool
Here’s an important reason to lower the water level in a swimming pool when winterizing.
If the water level is not properly lowered in a swimming pool when it is closed for the season, that is, the water level is at or above the skimmer (Figure SP-1), the water near the surface of the pool can freeze during the winter months forming an ice float and interlock itself into the opening of the skimmer, a jet nozzle, and/or other penetration.
During the time of thawing water under and around the ice float may be able to evaporate, drain from the pool due to a leak, and/or drain from the pool due to damage at the skimmer, jet nozzle, or other penetration. The loss of water will lower the level of the water in the pool and cause the ice float to drop. A significant drop in the height of the ice can damage the liner, the skimmer, and/or jet nozzle, or other penetration leading to additional water loss.
Eventually the ice may become supported on the thin metal wall of the swimming pool. A one foot deep by 24 foot diameter ice float weighs approximately 28,000 pounds. Since a thin metal swimming pool wall is not designed to support this weight it is prone to buckling, as shown in Figures SP-2 and the featured photo above.
So, remember to lower the level of the water in your pool this fall.