Swimming Pool Blog
by Rob, December 19, 2008
FROZEN SWIMMING POOL!
If your in ground pool develops a thin sheet of ice across the surface, chances are there is nothing to worry about. If you don't winterize your pool, be sure to keep the pump running, moving water through the pipes and equipment, so that it won't freeze within the pool plumbing. If the ice sheet becomes thick, then it may put pressure on your in ground pool tile and skimmers, or above ground pool walls.
Most pool tile is frost free, built to withstand chipping from ice damage, but best practice is to keep the water beneath the tile band if it freezes more than 1/2" thick. Pool Skimmers can crack from expansive pressure on the inner walls of a skimmer. Use a Gizzmo or fill a algaecide bottle 1/2 full with antifreeze or small pebbles.
Ice sheets can be damaging to vinyl liners if your pool has a leak. If a liner pool loses several inches of water beneath an ice sheet, the sheet can fall, and damage the pool liner. Add water if necessary, and don't pump out pool water beneath an ice sheet.
Mesh Safety Covers can look as if they are going to break under a heavy snow or ice load. It won't. The cover itself actually freezes to the surface, and will spring back to a taut fit after the thaw. Do not attempt to shovel snow off of a mesh pool cover. Lower the water level before a deep freeze, never during. This hotel pool in Boston above, should keep the water lower than in the picture. Lowering the water level after the pool has frozen may cause damage to the cover, or a vinyl liner, as mentioned above.
After the ice and snow melts, a good method to lower water level in a winter pool is to place a small pump in the pool skimmer. This will pump down to the bottom of the tile band, a good place to be. Another option is to place the pump on the first step. If the pool is already frozen more than slightly, wait for a bit of a thaw.
For safety pool covers, be careful not to lower the pool more than 12" below the tile line. This could damage a safety pool cover which needs the water level to help support the snow load. The best place for the water level in a safety cover on an in ground pool is 1-10" below the tile. Depending on how wet the winter is ~ you may need to lower the water level several times.
For Above Ground pools, the practice is different. Use an Ice Equalizer or Air Pillow to keep the ice from freezing very solid in your pool. Above Ground pool walls can only take so much ice expansion, and if ice sheets form in the skimmer, and the water level is pump or leaks out, it can cause real damage. Another practice is to use Floating milk jugs, 1/2 filled with an antifreeze mix or with small pebbles. (Do Not add pool antifreeze directly to pool water). Use Air Pillows to prevent a continuous ice sheet, and use skimmer covers to keep pool water out of the skimmer.
All pool types need to keep water in the pool during winter, do not drain your pool to avoid the ice! Pools can pop out of the ground. You don't want to end up like this guy!
OK, now for some fun - found this video of some teenage hooligans ~ really, I don't know them! Enjoy.